HomeMy WebLinkAboutPR 21002: A RESOLUTION AUTHORIZING THE RENTAL OF AN AQUAROBIC SYSTEM DISK CI
j
iii? -! r !lru.
--,:.
Te.tas
INTEROFFICE MEMORANDUM
Date: August 7, 2019
To: The Honorable Mayor and City Council
Through: Ron Burton, Interim City Manager
From: Donald Stanton, Interim Director of Water Utilities
RE: PR 21002—A Resolution Authorizing the Rental of an Aquarobic System Disk
Introduction:
The collection system in Sabine Pass is in a failed state. In order for the pipebursting crew to
replace the pipe, the wastewater has to be pumped from the collection system through the
wastewater plant. Excessive Inflow and Infiltration (I/I), due to tidal waters and inflow points,
make it impossible to replace pipe. This unit will enable Wastewater Operators to adequately
treat the extra flow of wastewater through the plant while maintaining wastewater discharge
quality compliance. This technology is patented and should be considered sole source. The
aquarobic system disk will be rented from Aqua-Aerobic Systems, Inc. of Loves Park, Illinois
at a rate of$10,000 per month, for a total rental and installation cost not to exceed $190,000 for
an estimated 18 months from FY 2020 account number 405-1621-532.83-00, Sewer System.
Background:
The collection system in Sabine Pass is in a failed state. In order for the pipebursting crew to
replace the pipe, the wastewater has to be pumped from the collection system. Excessive Inflow
and Infiltration(I/I), due to tidal waters and inflow points, make it impossible to replace pipe.
Budget Impact:
The aquarobic system disk rental will be at$10,000 a month, for a total of$190,000. Rental for
the equipment is in the FY2020 budget in 405-1621-532.83-00, Sewer System.
Recommendation:
It is recommended that City Council approve PR 21002, authorizing the City Manager to rent a
filter system for up to 18 months for a total cost not to exceed$190,000.
"Remember,we are here to serve the Citizens of Port Arthur"
PR No. 21002
8/7/2019 bw
Page 1 of 3
RESOLUTION NO.
A RESOLUTION AUTHORIZING THE CITY MANAGER TO
RENT FOR UP TO 18 MONTHS A FILTER SYSTEM WITH AQUA-
AEROBIC SYSTEMS, INC. OF LOVES PARK, ILLINOIS, TO
ENABLE DEWATERING OF COLLECTION SYSTEM AND
ADEQUATE TREATMENT OF ELEVATED FLOWS IN SABINE
PASS FOR A CONTRACT PRICE OF $190,000.00; FUNDING IS
AVAILABLE IN FY2020, ACCOUNT NO. 405-1621-532.83-00,
SEWER SYSTEM.
WHEREAS,the collection system of Sabine Pass is in a failed state; and,
WHEREAS, the wastewater has to be pumped from the collection system and treated at
the Sabine Pass wastewater treatment plant to enable the pipebursting crew to replace pipe and
manholes; and,
WHEREAS,the aquaerobic filter disc unit will enable staff to process an adequate amount
of water from the collection system so that the repairs can take place; and.
WHEREAS, the total installation and rental cost for up to 18 months is not to exceed
$190,000.00; and,
WHEREAS, a copy of the quote is attached hereto as Exhibit"A"; and,
WHEREAS, this purchase is authorized by Procurement Policies and Procedures Section
3-105 Sole Source Procurement, b) Compatibility—The product must match an existing brand of
equipment for compatibility and is available from only one supplier(Exhibit"B"); and,
WHEREAS, this procurement is exempt from the bid process under Texas Local
Government Code Section 252.022, General Exemptions (a) (7) (D), captive replacement parts or
components for equipment; and,
WHEREAS,the City of Port Arthur's Water Utilities Department has set aside funding in
the FY2020 budget in 405-1621-532.83-00, Sewer System.
PR No. 21002
8/7/2019 bw
Page 2 of 3
NOW,THEREFORE,BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY
OF PORT ARTHUR:
Section 1. That the facts and opinions of the preamble are true and correct.
Section 2. That the City Manager is hereby authorized to rent an aquaerobic filtration
system from Aquaerobic Systems Inc. of Loves Park, Illinois,for the dewatering of the wastewater
collection system in Sabine Pass.
Section 3. That a copy of the caption of the Resolution be spread upon the Minutes of the City
Council.
READ, ADOPTED AND APPROVED this the day of , A.D. 2019 at
a meeting of the City of Port Arthur,Texas by the following vote: AYES:
Mayor:
Councilmembers:
NOES:
Thurman "Bill" Bartie
Mayor
ATTEST:
Sherri Bellard
City Secretary
APPROVED AS TO FORM: APPROVED FOR ADMINISTRATION:
Ad.! . 1 4 C
V eno Ron Burton
Ci ttoi, Interim City Manager
PR No. 21002
8/7/2019 bw
Page 3 of 3
De'Zi-e''.-- ' ,?‘St ---''
Donald Stanton
Interim Director of Water Utilities
APPROVED AS TO AVAILABILITY OF
FUNDS:
(‘'.A-'01-i --,
Kandy Daniel Clifto ilhams, CPPB
Interim Finance Director Purchasing Manager
EXHIBIT "A"
r� AQUA-AEROBIC SYSTEMS, INC.
A Metawater Company
AQUA-AEROBIC SYSTEMS, INC. RENTAL AGREEMENT
This Agreement is made and entered into at Loves Park, Illinois, by and between AQUA-
AEROBIC SYSTEMS, INC., an Illinois corporation, having its principal place of business at
6306 N. Alpine Road, Loves Park, Illinois hereinafter called ("Aqua-Aerobic") and (City of Port
Arthur) with its principal place of business in (Port Arthur, TX) hereinafter called ("Renter").
In consideration of the mutual promises, covenants, and agreements herein contained,
the parties agree as follows:
1. EQUIPMENT RENTAL
a. Aqua-Aerobic does hereby agree to rent to Renter and Renter does hereby agree to
hire from Aqua-Aerobic the Equipment described on Schedule A attached
(hereinafter called "Equipment") on the terms and conditions herein contained.
Accessories and services are not covered under this Agreement and must be
purchased separately.
2. TERM
a. This Agreement shall commence when the Equipment is shipped from Aqua-
Aerobic's place of business at Loves Park, Illinois, and shall continue for a minimum
term of three (3) consecutive months thereafter. It is estimated that shipment will
occur (four) (4) weeks after signed agreement, insurance certificate, and first
month's rental payment are received by Aqua-Aerobic. The rental will conclude
when the Equipment is returned to Aqua-Aerobic in rentable condition. Should
Aeration&Mixing Biological Processes Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,1L 61111-7655 p 815.654.2501 1815.6542508 www.aqua-aerobic.com
repairs not due to ordinary wear and tear be required as outlined in paragraph 8.a. of
this Agreement, the term will continue until the Equipment has been repaired.
3. RENTAL PAYMENTS
a. The Renter shall make monthly payments to Aqua-Aerobic in the amount of (ten
thousand) dollars ($10,000.00) per unit. Payments are due monthly, in advance, on
the same day each month. All delinquent payments are subject to past due charges
of one point five (1.5) percent per month. The term for the rental begins on the date
the Equipment ships from Aqua-Aerobic and ends on the date the Equipment is
returned to Aqua-Aerobic or to any location designated by Aqua-Aerobic.
b. The Renter shall make a Security Deposit in the amount of (five thousand) dollars
($5,000.00) prior to the Equipment shipping to Renter's site. The security deposit
shall be refunded to Renter upon the Equipment being returned to Aqua-Aerobic in a
clean condition with no damage except for normal wear and tear. Should the unit
not be returned clean or is in a damaged condition, Aqua-Aerobic shall clean
and/or repair the Equipment and deduct these expenses from the security
deposit. Should the security deposit not be adequate to cover these expenses, the
additional expenses shall be billed to the Renter and are due upon receipt. Aqua-
Aerobic will provide a check list that specifies the cleaning that must be
completed prior to the Equipment being loaded onto the truck for return to
Aqua-Aerobic. Please note the truck driver can refuse the Equipment if it is
not properly cleaned and all expenses associated with a second trip by the
driver to the installation location will be at Renter's expense.
c. If a field service trip for supervisory pre-operation inspection has been purchased,
the Renter is responsible for the Equipment being installed according to the
2
Aeration&Mixing Biological Processes Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
instructions provided by Aqua-Aerobic (including fully-operable electrical and
plumbing connections) PRIOR to the arrival of Aqua-Aerobic's field service
technician. If the Equipment has not been installed according to these instructions,
Renter will be responsible for all costs associated with the extra day(s) and/or trips
for Aqua-Aerobic's field service technician to verify proper installation.
4. CARE, USE AND LOCATION
a. Renter, at its own cost and expense, shall keep and maintain the Equipment in good
repair, condition and working order, including chemical cleaning of the filter cloth
media if it is determined to be required. The supply of chemicals and labor to clean
the filter shall be provided by the Renter. Aqua-Aerobic or its authorized
representative shall have the right to inspect the Equipment at any reasonable time
during normal business hours.
b. Renter shall allow only qualified and duly trained operators to use, operate, maintain,
and/or repair the Equipment. Renter shall at all times use the Equipment in a careful
and prudent manner and in compliance with all laws and regulations. Should any
parts be required to repair the Equipment during the rental period, these must be
purchased from Aqua-Aerobic.
c. Renter is responsible for all "Daily" and "Monthly" filter maintenance tasks per the
Lubrication Schedule and Maintenance Schedule included within Section 6 of Aqua-
Aerobic's Operation & Maintenance Manual. For every six (6) months of rental
operation, one (1) field service trip for supervisory assessment of the rental filter(s)
will be added to Renter's invoice at (one thousand five hundred) ($1,500.00). This
supervisory assessment will be performed by an Aqua-Aerobic field service
technician to verify each filter is being properly maintained. During the trip, the
3
Aeration&Mixing Biological Processes Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
technician will perform the "Annually" and "Service Hours" maintenance tasks per
the Lubrication Schedule and Maintenance Schedule included within Section 6 of
Aqua-Aerobic's Operation & Maintenance Manual.
5. DELIVERY, INSTALLATION, AND REDELIVERY COSTS
a. Renter shall pay all transportation charges from Aqua-Aerobic's place of business at
Loves Park, Illinois, to the installation location. Renter shall also pay for all costs
related to the Equipment including but not limited to, unloading, loading, installation,
dismantling, start-up, cleaning, testing, and sampling.
b. Upon termination of this Agreement, Renter shall return the Equipment to Aqua-
Aerobic freight prepaid, in good repair, condition, and working order; ordinary wear
and tear excepted. Prior to return shipment to Aqua-Aerobic, Renter shall
remove all exterior dirt, offensive odor, and chemical or biological materials and shall
tag the shipment with a valid RMA number obtained from Aqua-Aerobic. Refer to
paragraph 3.b. for additional instructions and implications to the security deposit
associated with non-compliance with Aqua-Aerobic's instructions.
c. If requested by Aqua-Aerobic, Renter shall return the Equipment to any location
designated by Aqua-Aerobic provided that the freight charges shall not be greater
than those for delivery to Loves Park, Illinois.
6. TITLE, PERSONAL PROPERTY
a. The Equipment shall at all times remain the property of Aqua-Aerobic and Renter
shall have no right, title, or interest therein, except as the Renter. Renter agrees to
execute any statement, including Uniform Commercial Code financing statements
reasonably requested by Aqua-Aerobic for the purpose of filing and recording to
indicate that Renter's interest in the Equipment is solely that of a Renter. Renter
4
Aeration&Mixing Biological Processes Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
agrees that it will, at its cost and expense, defend Aqua-Aerobic's title in the
Equipment against claims of any third persons claiming any right, title, or interest in
the Equipment through the Renter. The Equipment shall at all times remain
personal property, notwithstanding the fact that the Renter may attach it to real
property or improvements.
7. NET AGREEMENT, TAXES
a. The rental payments shall be net to Aqua-Aerobic and Renter shall pay any and all
sales, use, excise, personal property, or similar taxes, customs duties, and import
fees levied by any governmental authority or charges imposed upon the possession
of the Equipment during the term of the Agreement, excepting only any income
taxes imposed upon Aqua-Aerobic. If Aqua-Aerobic is required by any
governmental or other taxing authority to collect and remit any such tax, duty, or fee,
the Renter shall be separately billed at such time for these amounts and payment
shall be remitted within ten (10) days of invoicing.
8. RISK OF LOSS AND INDEMNITY
a. Aqua-Aerobic shall assume all loss resulting from normal wear and tear. Renter
shall return the Equipment to Aqua-Aerobic at the end of the rental period in the
same condition as received — less normal wear and tear. The Equipment shall be
clean and free of any waste and waste residue. If disposal or decontamination of
the Equipment is required due to the processing of a hazardous waste, it shall be the
responsibility of the Renter. If in Aqua-Aerobic sole opinion, there is any accelerated
wear due to the operation whether caused by decomposition from chemical action,
excessive wear due to abrasion or other extreme loading or damage from misuse,
accident, neglect or other improper operations, this shall be billable to the Renter.
5
Aeration&Mixing Biological Processes ! Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61 111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
Any charges for repairs that might arise from the aforementioned damages will be
billed at normal prices and are due upon receipt. Renter shall indemnify and hold
harmless Aqua-Aerobic from all claims, actins, costs, expenses, damages and
liabilities including attorney's fees arising out of or in connection with the use the
equipment by Renter.
b. Renter shall indemnify and hold harmless Aqua-Aerobic, its officers, employees and
agents against all claims, liabilities, losses, damages and expenses, of every
character and kind whatsoever, for property damage, bodily injury, sickness and/or
disease resulting in whole from either the negligence and/or willful misconduct of
Renter. In no event shall either party be liable for loss or profit, revenues, or
product; or for any other indirect, consequential, and special damages.
9. INSURANCE AND LIABILITY
a. To the extent of its negligence, Renter ASSUMES ALL RISKS and will pay all costs
and expenses of any character, arising from the use, possession, or maintenance of
the Equipment and agrees to indemnify and save harmless Aqua-Aerobic from and
against all loss or damage or claims for loss or damage (including attorney's fees for
injury to, or death of persons or damage to property caused by said Equipment , or
arising out of the use, possession, and maintenance of the Equipment) and to give
Aqua-Aerobic immediate written notice of any such loss or damage, whatsoever.
Aqua-Aerobic is not responsible for workdays lost due to mechanical problems
encountered with the Equipment.
b. Renter shall, at its own expense, maintain insurance coverage as follows:
i. Workman's compensation insurance and such other employee insurance as
shall be required by applicable state/provincial and federal laws for each of
6
Aeration&Mixing Biological Processes ' Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 t 815.654.2508 www.aqua-aerobic.com
the Renter's employees associated with the Equipment or the use thereof.
Renter shall provide a Workman's Compensation waiver of subrogation in
favor of Aqua-Aerobic.
ii. Comprehensive general liability insurance in an amount not less than
$2,000,000 combined single occurrence limits for bodily injury and/or property
damage.
iii. Property damage and loss insurance for the full replacement value of the
Equipment as indicated in paragraph 12. Aqua-Aerobic Systems, Inc., as the
owner of the Equipment, shall be named as an Additional Insured. The
Renter's insurance certificate shall, therefore, show the following as an
Additional Insured: Aqua-Aerobic Systems, inc., 6306 North Alpine Road,
Loves Park, IL 61111.
iv. The specified insurance coverage may be provided by a combination of
primary and umbrella coverage.
v. Renter shall provide Aqua-Aerobic with proof of such insurance prior to
shipment of the Equipment and shall maintain such insurance in effect during
the term of this Agreement. Aqua-Aerobic shall be notified in writing of any
changes in coverage or cancellation at least thirty (30) days prior to the
change taking place.
10. DEFAULT AND REMEDIES
a. If Renter shall default in the payment of any rental payment, or otherwise breach any
of the terms herein contained, or in the event any bankruptcy or insolvency
proceeding is commenced by or against the Renter, or the Renter shall make an
assignment for the benefit of creditors, or any action shall be taken against or by the
7
Aeration&Mixing Biological Processes Filtration Membranes Process Control&Monitoring : Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.cori
Renter to accomplish such purpose, or if a receiver of the property or the business of
the Renter is appointed, then and in any such event, in addition to any and all other
remedies otherwise available to Aqua-Aerobic at law or in equity for breach of
contract, Aqua-Aerobic shall have the immediate right and Renter does hereby grant
Aqua-Aerobic the right to enter upon the premises of the Renter and to remove the
Equipment, with or without legal process. This grant of authority shall be irrevocable
until all the Equipment is returned to Aqua-Aerobic.
b. Renter shall pay to Aqua-Aerobic upon demand, all costs and expenses, including
legal and collection fees, incurred by Aqua-Aerobic in enforcing the terms,
conditions, or provisions of this Rental Agreement or in protecting Aqua-Aerobic's
rights and interest in the Rental Agreement and Equipment.
11. HOLDOVER
a. In the event upon termination of this Agreement, Renter shall continue to retain
possession of the Equipment, Renter agrees to pay to Aqua-Aerobic the monthly
rental payment, or portion thereof, during which time Renter retains such
possession. During such holdover period, all of the other terms and conditions
herein contained shall continue. Renter agrees that during any such holdover period
it shall immediately redeliver the Equipment to Aqua-Aerobic upon Aqua-Aerobic's
written request.
12.WARRANTIES
a. Aqua-Aerobic makes no warranty or representation, expressed or implied, (including
any implied warranty of merchantability or fitness for a particular purpose) as to the
appropriateness of the Equipment for any tasks or that the Equipment is appropriate
for any given use to which Renter may put the Equipment.
8
Aeration&Mixing Biological Processes Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p Si 5.654.2501 f 815.654.2508 www.aqua-aerobic.com
13.SPECIAL USE
a. Renter shall immediately inform Aqua-Aerobic of any special hazard risks involved
and any treatment of hazardous waste by the Equipment of which the Renter is
aware or shall become aware which would require disposal, decontamination, and
other extraordinary cleaning of the Equipment upon completion of the rental.
14. FORCE MAJEURE
a. Neither party shall be liable under this Agreement for delays or other non-
performance (except for payment of money for Equipment defined under this
agreement or for services already rendered) caused by any unusual occurrence
beyond the party's reasonable control, including but not limited to war, fire, strikes,
other labor troubles, unforeseen breakage of Equipment, accidents beyond the
reasonable control of either party, acts of God, delays of common carriers, and
unforeseeable actions of governmental authority, laws/rules, and/or regulations.
15.NOTICE
a. Any written notice required hereunder shall be deemed given when personally
delivered, or when received by registered or certified mail, return receipt requested,
or when received by courier service and addressed as follows:
i. Aqua-Aerobic Systems, Inc.
6306 N. Alpine Rd.
Loves Park, IL 61111
ii. Renter:
City of Port Arthur
444 4th St.
Port Arthur, TX 77640
9
Aeration&Mixing i Biological Processes Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
HEADINGS
a. The headings to the paragraphs of this Agreement are for convenience only and are
not part of this Agreement and shall have no effect on the construction or
interpretation of any part of this Agreement.
17.MISCELLANEOUS
a. This Rental Agreement contains the entire Agreement between the parties and no
modification may be made unless in writing. This Rental Agreement shall be
governed by and construed under the laws of the State of Illinois and venue for any
legal action to enforce the rights must be asserted in Winnebago County, Illinois.
IN WITNESS WHEREOF, this Rental Agreement has been executed at Loves Park, Illinois on
the day and year last noted below (effective date of the Agreement):
AQUA-AEROBIC SYSTEMS, INC.
By (Printed Name):
Its (Title):
Date:
RENTER:
By (Printed Name):
Its (Title):
Date:
10
Aeration&Mixing ! Biological Processes Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 Ni Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 1815.654.2508 www.aqua-aerobic.com
•
AQUA-AEROBIC SYSTEMS, INC. RENTAL AGREEMENT
SCHEDULE A
EQUIPMENT:
The 6 disk AquaDisk filter has an average capacity of 1.5 MGD and a maximum capacity of 3.0
MGD. Each disk has an effective filtration area of 53.8 ftz. The 10 micron filter media has a
maximum solids loading of 2.7 lbs/ft2.
• Unit is designed for outdoor use
• Unit comes with chlorine resistant pile cloth media
• 460 v 3 phase 30 amp power required
• A crane is required to load and unload the filter
• Unit dry weight is 12,400 lbs and operating weight is 61,200 lbs
• Influent, effluent and overflow flanges are 14"
In order to install the unit, the Renter would need a concrete pad, and then hook up influent,
effluent and backwash lines, and run power to the panel.
TO BE SHIPPED TO:
Please advise complete "ship to" address.
To expedite your order, please provide the following shipping instructions with your order:
Earliest acceptable Equipment on-site date:
Ship to Address
Zip
Jobsite Contact Name:
Jobsite Telephone Number:
Jobsite Contact's Cell Number:
Truck driver will provide advance delivery notification to the contact listed above, unless
otherwise noted.
Deliveries are accepted on which days of the week (circle all that apply):
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
11
Aeration&Mixing ! Biological Processes ! Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
Please note any upcoming holidays/dates where jobsite location is not in operation during the
standard operational hours/days shown above:
Please confirm availability of a crane for off-loading the equipment and note advance notice
required to make arrangements for a crane:
Acceptable hours of delivery: AM to PM
You require 24 48 HOURS notice prior to DELIVERY (circle one or fill in blank)
12
Aeration&Mixing Biological Processes ' Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
•
Other delivery information you want relayed to the carrier and/or the driver:
Please confirm Billing Address:
Contact:
Phone:
Email:
Below is Aqua-Aerobic's banking information for electronic transfer of payments:
Bank Name: BMO Harris Bank N.A.
Bank location: 111 West Monroe, Chicago, IL 60603
Routing Number: 071000288
Company Name: Aqua Aerobic Systems, Inc.
Account Number: 1605617
Swift address: HATRUS 44
R3: 5/2/2019
13
Aeration&Mixing Biological Processes : Filtration Membranes Process Control&Monitoring Aftermarket Parts&Services
6306 N.Alpine Rd. Loves Park,IL 61111-7655 p 815.654.2501 f 815.654.2508 www.aqua-aerobic.com
EXHIBIT "B"
•
AQUA-AEROBIC SYSTEMS, INC.
A Metawater Company
ysew%=
August 15, 2019
Correspondence ID#: AAL-37577
City of Port Arthur
Attn: Donnie Stanton
444 4th St.
Port Arthur, Texas 77640
USA
Ph#409/983-8226
Project: PORT ARTHUR TX
RE: Sole Source Letter
AASI Project ID# 111864A
Dear Donnie,
The Aqua-Aerobic Systems, Inc. (AASI) AquaDisk® Cloth Media Rental Filter is of
AASI's proprietary design and fabricated to AASI specifications. AASI is the exclusive
original equipment manufacturer of the AquaDisk®Cloth Media Filter for use at the
Sabine Creek VWVfP. The control logic that we utilize for our cloth media filters is
customized on a per project basis and is proprietary to AASI.
As such, all equipment and components are manufactured to AASI's specifications,
including the PLC's and operator interfaces associated with the equipment.
Sincerely,
•A*
Jeff Ogle
Aftermarket External Sales Specialist
CC: Hartwell Environmental Corp. /ph#: 281/351-8501 /fx#: 281/351-8323
Matthew Davis/ Mdavis@hartwellenv.com
Aqua-Aerobic Systems, Inc.
John Dyson /jdyson@aqua-aerobic.com
Aeration&Mixing I Biological Processes I Filtration I Membranes ' Oxidation&Disinfection I Process Control I Aftermarket&Customer Service
6306 N Alpine Rd Loves Park.IL 61111-7655 p 815.654 2501 f 815.654 2508 www.aqua•aerobic coin
Page 2 of 2
May 3, 2018
Aeration&Mixing I Biological Processes I Filtration I Membranes I Oxidation& Disinfection I Process Control I Aftermarket&Customer Service
6306 N. Alpine Rd Loves Park. IL 61111-7655 p 815 654.2501 f 815 654 2508 www.aqua-aerobic.com
8/27/2019 United States Patent 6110374
USPTO PATENT FULL,-TEXT AND IMAGE DATABASE
Home Quick [Advanced Pat Num Help
Hit List Previous Next Bottom
View Cart Add to Cart'
Images
(3 of 4)
United States Patent 6,110,374
Hughes August 29, 2000
Treatment process for removing microbial contaminants suspended in wastewater
Abstract
A treatment process is disclosed for reducing the concentration of pathogenic microorganisms in a volume of
wastewater that contains a substantial concentration of pathogenic microorganisms less than about 10 microns in
size, less than about 5 microns in size, and less than about 0.1 microns in size. The process includes adding an
agglomerate-promoting agent, such as a coagulant chemical, to the volume of wastewater such that the solids
aggregates form in the volume of wastewater and include the pathogenic microorganisms. The volume of
wastewater is then passed through a filter cloth membrane to separate greater than about 50.0% of the
pathogenic microorganisms less than 10 microns in size from the volume of wastewater,to separate up to about
99.9% of the pathogenic microorganisms less than about 5 microns in size, and to separate up to about 99%of
the pathogenic microorganisms less than about 0.1 microns in size. The filter cloth membrane used is
constructed of random web needled polyester felt characterized by a free passage size through the filter cloth
membrane of greater than about 5 microns. More specifically,the treatment process can separate greater than
about 50.0% and up to about 99.9% of protozoan pathogens such as Cryptosporidium and Giardia from the
volume of wastewater.
Inventors: Hughes; Paul A. (Rockton, IL)
Assignee: Aqua-Aerobic Systems, Inc. (Rockford, IL)
Family ID: 22319414
Appl.No.: 09/107,960
Filed: June 30, 1998
Current U.S. Class: 210/638; 210/702; 210/728
Current CPC Class: BOLD 39/16 (20130101); CO2F 1/5236 (20130101); BOLD
2239/0613 (20130101); BOlD 2239/065 (20130101); BOlD
2239/0654 (20130101); CO2F 2303/04 (20130101); BOlD
2239/1233 (20130101); CO2F 1/44 (20130101); BOLD 2239/0659 (20130101)
Current International Class: BO 1D 39/08 (20060101); BO 1D 39/16 (20060101); CO2F 1/52 (20060101);
CO2F 1/44 (20060101); CO2F 001/52 0
Field of Search: ;210/702,721,725,727,728,754,764,638,639,651
References Cited [Referenced By]
patft.u spto.gov/n eta cgi/nph-Parser?Sect1=PT02&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-boot.html&r=3&f=G&I=50&col=AND&d... 1/15
8/27/2019 United States Patent:6110374
U.S. Patent Documents
4081365 March 1978 White et al.
4090965 May 1978 Fuchs
4173532 November 1979 Keoteklian
4229202 October 1980 Mullerheim et al.
4238334 December 1980 Halbfoster
5006251 April 1991 Takeishi et al.
5128040 July 1992 Molof et al.
5362401 November 1994 Whetsel
5374360 December 1994 Weis
5407572 April 1995 McGuire et al.
5407573 April 1995 Hughes
5429750 July 1995 Steele
5456836 October 1995 Jeffery et al.
5512076 April 1996 Gibson
5543056 August 1996 Murcott et al.
5552057 September 1996 Hughes et al.
5707524 January 1998 Potter
5711887 January 1998 Gastman et al.
5725770 March 1998 Henry
5733455 March 1998 Molof et al.
6027649 February 2000 Benedek et al.
Foreign Patent Documents
0 413 178 A2 Feb 1991 EP
3628203 Al Feb 1988 DE
Other References
Aqua-Aerobic Systems, Inc.,AquaDisk Filter Cloth-Media Filters Brochure, Bulletin#600A, p. 1,
Apr. 1996. .
Mecana Umwelttachnik AG, Mecana Disk Filter Description, section 3, Sep. 1991. .
Waterloo Biofilter Process/Product Description, http://darcy.uwaterloo.ca/partners/biofilter no date. .
Aqua-Aerobic Systems, Inc.,Aqua Filter Brochure, Copyright 1993, Bulletin No. 100M Jan. 1993. .
Aqua-Aerobic Systems, Inc.,A quaDisk Filter Cloth-Media Filters Brochure, Copyright 1996,
Bulletin#600A Apr. 1996. .
Huyck Austria Material Sheet, Type WE 134 no date. .
Mecana SA. Schmerikon, Specification Sheet, Filtercloths, Type 102 no date. .
Osmonics, Inc., Scale Sheet, P/N 17978, Copyright, 1984. .
Mecana Brochure, Functions of Disk Filter no date. .
Fundamentals of Chemistry for Enviromental Engineering, Colloidal Dispersions in Liquids Article,
pp. 332-339 no date. .
Mecana Disk Filter Description, Sep. 5, 1991. .
Ashland Chemical, Inc., The Role of Polymers in Liquid/Solids Separation, Apr. 28, 1992, PYM-
TP-5 no date. .
Zeta-Meter, Inc., Everything You Want to Know About Coagulation & Flocculation, Apr., 1993. .
Coagulation and Flocculation, Chapter 8, The Nalco Water Handbook,pp. 8.3-8.23 and 4.28 no
date..
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&1=50&co1=AND&d... 2/15
8/27/2019 United States Patent:6110374
Primary Examiner: Simmons; David A.
Assistant Examiner: Lawrence; Frank M.
Attorney, Agent or Firm: Michael Best& Friedrich LLP
Claims
What is claimed is:
1. A process for reducing the amount of microbial contaminants in wastewater, the process comprising the acts
of:
providing wastewater containing microbial contaminants;
promoting the agglomeration of microbial contaminants in the wastewater; and
filtering the wastewater including the agglomerated microbial contaminants through a filter membrane made of
cloth material to separate at least a portion of the microbial contaminants from the wastewater.
2. The process of claim 1 wherein said at least a portion is greater than about 50%.
3. The process of claim 1 wherein said at least a portion is greater than about 99%.
4. The process of claim 1 wherein the microbial contaminants include microorganisms less than about 10
microns in size.
5. The process of claim 1 wherein the microbial contaminants include microorganism less than about 5 microns
in size.
6. The process of claim 1 wherein the microbial contaminants contain microorganisms less than about 1.0
micron in size.
7. The process of claim 1 wherein the microbial contaminants include microorganisms less than about 0.1
micron in size.
8. The process of claim 1 wherein the microbial contaminants include viruses.
9. The process of claim 1 wherein the microbial contaminants include protozoans.
10. The process of claim 1 wherein the microbial contaminants include bacteria.
11. The process of claim 1 wherein the filter membrane made of cloth material includes a random web needled
polyester felt.
12. The process of claim 1 wherein the filter membrane is characterized by an average free passage through the
filter membrane of greater than about 5 microns.
13. The process of claim 1 wherein the promoting act includes adding an agglomerate-promoting agent.
14. The process of claim 13 wherein the agglomerate-promoting agent includes a coagulant.
15. The process of claim 13 wherein the agglomerate-promoting agent includes one of ferric chloride or alum.
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-boot.h tml&r=3&f=G&I=50&col=AND&d... 3/15
8;27/2019 United States Patent: 6110374
16. The process of claim 1 wherein the promoting act includes adding a coagulant to the wastewater and adding
a flocculent to the wastewater.
17. The process of claim 16 wherein the flocculent includes an organic polyelectrolyte.
18. A process for reducing the concentration of pathogenic microorganisms in wastewater,the process
comprising the acts of:
providing wastewater containing a concentration of pathogenic microorganisms including at least one of
protozoans, bacteria, and viruses;
adding an agglomeration-promoting agent to the wastewater to form solids aggregates which include the
pathogenic microorganisms; and
filtering the wastewater through a filter membrane made of cloth material to reduce the concentration of
pathogenic microorganisms in the wastewater.
19. The process of claim 18 wherein in the filtering step, the concentration of pathogenic microorganisms is
reduced by greater than about 50%.
20. The process of claim 18 wherein in the filtering step, the concentration of pathogenic microorganisms is
reduced by greater than about 90%.
21. The process of claim 18 wherein in the filtering step, the concentration of pathogenic microorganisms less
than about 10 microns in size is reduced by greater than about 50%.
22. The process of claim 18 wherein in the filtering step, the concentration of pathogenic microorganisms less
than about 5 microns in size is reduced by greater than about 50%.
23. The process of claim 18 wherein in the filtering step, the concentration of viruses is reduced by greater than
about 50%.
24. The process of claim 18 wherein the protozoans include Cryptosporidium and Giardia and wherein in the
filtering step, the concentration of Cryptosporidium and Giardia are reduced by greater than about 50%.
25. The process of claim 18 wherein the filter membrane made of cloth material includes random web needled
polyester felt.
26. The process of claim 18 wherein the filter membrane is characterized by an average free passage size
through the filter membrane of greater than about 5 microns.
27.. The process of claim 18 wherein in the adding step, a coagulant is added.
28. The process of claim 27 wherein the coagulant is selected from iron salts, aluminum salts, activated silica,
bentonite, sodium chloride, cationic polyelectrolytes, or mixtures thereof.
29. The process of claim 18 wherein in the adding step, a flocculent is added.
30. The process of claim 29 wherein the flocculent is selected from aluminum sulfate, lime, iron salts,
polyelectrolytes, or a mixtures thereof.
31. A process for reducing the concentration of viruses in wastewater, said process comprising the acts of:
patft.uspto.gov/netacgiinph-Parser?Sect1=PT02&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&co1=AND&d... 4/15
8/27/2019 United States Patent:6110374
adding an agglomeration-promoting agent to wastewater to form suspended aggregates which include viruses;
and
passing the wastewater with aggregates through a cloth filter to reduce the concentration of viruses.
32. The process of claim 31 wherein the act of passing the wastewater through a cloth filter includes reducing
the concentration of viruses by greater than about 50%.
33. The process of claim 31 wherein the act of passing the wastewater through a cloth filter includes reducing
the concentration of viruses by greater than about 90%.
34. The process of claim 31 wherein the cloth filter is constructed of a material including random web needled
polyester felt.
35. The process of claim 31 wherein the cloth filter is characterized by an average free passage size through the
cloth filter of greater than about 5 microns.
36. The process of claim 31 wherein the act of adding an agglomerate-promoting agent includes adding a
coagulant to the wastewater.
37. The process of claim 36 wherein the coagulant is selected from iron salts, aluminum salts, activated silica,
bentonite, sodium chloride, cationic polyelectrolytes, or mixtures thereof.
38. The process of claim 31 wherein the act of adding an agglomerate-promoting agent includes adding a
flocculent to the wastewater.
39. The process of claim 38 wherein the flocculent is aluminum sulfate, lime, iron salts, polyelectrolytes, or a
mixture thereof.
40. A process for reducing the concentration of viruses in wastewater, the process comprising the acts of:
adding an agglomerate-promoting agent to wastewater to form solids aggregates which include viruses; and
passing the wastewater and aggregates through a filter to reduce the concentration of viruses in the wastewater,
wherein the filter is a cloth filter fabricated from material including a random web polyester felt.
41. The process of claim 40 wherein said filter is fabricated from a cloth material having a free passage size
through the cloth of greater than 5 microns.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a wastewater treatment process and, more particularly, to a process for
removing microbial contaminants, including pathogenic microorganisms, contained in wastewater.
Pathogenic microorganisms are disease-causing agents that can contaminate domestic and recreational water
supplies through the discharge of poorly treated industrial and municipal wastewater. Pathogenic
microorganisms transmitted in this manner can cause major health problems to local communities and is often a
causative factor in outbreaks of dysentery, cholera, typhoid, gastroenteritis, and other diseases. To minimize the
chances of such outbreaks occurring, effluent standards are imposed on facilities which discharge treated
wastewater into the environment.
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=H ITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&col=AND&d... 5/15
8/27/2019 United States Patent: 6110374
Most pathogenic microorganisms can be classified as protozoan, bacteria, and viruses. The viruses of particular
concern to wastewater treatment are water-borne polio viruses, including rota viruses. Bacteria comprise the
largest group of pathogenic microorganisms and include Salmonella sp., Shigella sp., Escherichia coli, and a
broad variety of others generally known. The most common bacteriological diseases include shigellosis, which
causes dysentery, food poisoning, and cholera. Protozoan pathogens include Giardia sp. which causes giardiasis,
one of the most prevalent water-borne diseases in the United States, and Cryptosporidium sp., which causes
dysentery.
The treatment processes employed in wastewater treatment may be categorized as primary, secondary, and
tertiary. In typical primary treatment, larger suspended solids are removed from raw wastewater using
mechanical means and/or by gravity settling. In secondary treatment, biological treatment processes may be
employed to metabolize organic matter to solid material and byproducts, followed by the removal of solid
matter, usually by gravity settling. Secondary treatment may also include biological nutrient removal. Treatment
beyond secondary treatment is commonly referred to as tertiary treatment. More recent tertiary treatment
processes have employed physical-chemical or biological processes followed by chemical precipitation to lower
the concentration of pathogenic microorganisms and other fine suspended solid particles in secondary-treated
wastewater.
Filtration techniques are also used in some tertiary treatment processes. More specifically, granular media type
filters such as deep-bed sand filters are used to strain out fine particles from the wastewater stream prior to
disinfection. The degree to which these filters can separate pathogenic microorganisms from a wastewater
stream varies with respect to the type of pathogenic microorganisms in the stream and, more particularly, to the
size of the microorganisms. While most bacteria are about 10 microns or less in size, most protozoans are less
than 5 microns and most viruses are less than 0.1 microns. The use of granular media type filters has proven
more effective in removing some larger particles from wastewater streams than in removing small particles such
as viruses. Deep bed multi-media filters have been employed to remove up to 30% to 40% of viruses and
bacteria from a given volume of wastewater.
Despite prior treatment efforts, outbreaks of diseases continue to be linked to water-borne pathogenic
microorganisms contaminating domestic water supplies and recreational water supplies. These occurrences have
generated increasing pressure on responsible authorities to implement effluent standards which further reduce
the concentrations of microbial contaminants, including pathogenic microorganisms, that can be discharged in
treated industrial and municipal wastewater. Various treatment techniques are available for improving the degree
to which microbial contaminants can be removed from a wastewater stream. These treatment techniques vary in
cost, complexity, as well as in effectiveness.
Filtration techniques,particularly the use of sand filters and other granular-media type filters, may be
advantageous as a tertiary treatment process because these techniques typically involve a simple operation and
can be very cost effective compared to most chemical and biological processes. However, there is a general
perception in the wastewater treatment industry that the effectiveness of filtration techniques to remove
microbial contaminants, including pathogenic microorganisms, from wastewater cannot be substantially
improved beyond the removal rate or degree currently achievable with sand filters and other granular media type
filters.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide a wastewater treatment process that employs a
filtration technique capable of reducing the concentration or amount of microbial contaminants, including
pathogenic microorganisms, in a given volume of wastewater by at least about 30%to 40% and more preferably,
up to over about 99%to 99.9%. Such a reduction or removal rate is a vast improvement to the 30%to 40%rates
presently achievable with prior art filtration processes. It is a further object of the invention to provide such a
process that is particularly adapted to the tertiary treatment of wastewater(e.g., secondary effluent).
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&col=AND&d... 6/15
8/27/2019 United States Patent:6110374
The invention provides a treatment process for reducing the concentration of microbial contaminants suspended
or contained in wastewater. The process includes providing a volume of wastewater that contains a substantial
concentration of suspended microbial contaminants (e.g., in excess of about 10.sup.2 /100 ml) including
pathogenic microorganisms and then promoting the agglomeration of suspended solids in the wastewater to form
suspended solids aggregates which include microbial contaminants. Agglomeration of solids aggregates may be
promoted by adding an agglomerate-promoting agent such as a coagulant and/or flocculant to the volume of
wastewater. The volume of wastewater including the solids aggregates is then passed through a filter membrane
or filter media, thereby separating microbial contaminants from the wastewater. The filter membrane may be
constructed from a cloth material,preferably needled polyester felt having a random web construction and
characterized by an average free passage through the filter membrane of greater than about 5 microns.
In one aspect of the invention, the step of passing the volume of wastewater through the filter membrane
separates greater than about 50% of the microbial contaminants (e.g., pathogenic microorganisms) from the
volume of wastewater. The volume of wastewater may also contain a substantial concentration of microbial
contaminants or microorganisms less than about 10 microns (e.g.,protozoan, bacteria, and/or viruses) or less
than about 5 microns in size (e.g.,protozoan and/or viruses). In an unexpected manner, the step of passing the
volume of wastewater through the filter membrane has been found to separate greater than about 50% (and up to
greater than about 99.9%) of such microbial contaminants from the volume of wastewater.
Further, the volume of wastewater may contain a substantial concentration of microbial contaminants less than
about 0.1 microns in size (e.g., in excess of 0.05/100 ml), including, but not limited to viruses. In an unexpected
manner, the step of passing the volume of wastewater through the filter membrane has been found to separate
greater than about 50% (and up to greater than about 99%) of such microbial contaminants from the volume of
wastewater.
Before embodiments of the invention are explained in detail, it is to be understood that the invention is not
limited in its application to the details of the apparatus, composition or concentration of components, or to the
steps or acts set forth in the following description. The invention is capable of other embodiments and of being
practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used
herein is for the purpose of description and should not be regarded as limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a wastewater treatment system capable of employing a treatment process according to
the invention.
FIG. 2 is a side view of a filter apparatus in the wastewater treatment system.
FIG. 3 is a front view of the filter apparatus.
FIG. 4 is a cross-sectional view through a filter disk of the filter apparatus.
DETAILED DESCRIPTION
The wastewater treatment process according to the invention is particularly adapted to the treatment of
wastewater containing a substantial concentration of microbial contaminants including pathogenic and non-
pathogenic microorganisms less than about 30 microns in size. In one aspect of the invention, the process is
employed in the treatment of wastewater containing in excess of about 10.sup.2 /100 ml of microbial
contaminants generally including pathogenic microorganisms such as protozoans, bacteria, and viruses.
Wastewater generated in municipal and agricultural facilities, as well as sewage and some industrial wastewater,
generally contain a substantial concentration(e.g., about 10.sup.6 to 10.sup.9 /100 ml) of suspended microbial
contaminants. One focus of the invention is on the treatment of these types of wastewater. Another focus of the
invention is on the treatment of secondary effluent which contains a substantial concentration (e.g., in excess of
about 10.sup.2 /100m1) of microbial contaminants, including pathogenic microorganisms.
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r-3&f=G&I=50&co 1=AND&d... 7/15
8)27/2019 United States Patent:6110374
The wastewater treatment process according to the invention is also employed in the removal of microbial
contaminants that are less than about 10 microns in size (e.g., most bacteria, protozoans, and viruses) or less than
about 5 microns in size (e.g., protozoan pathogens such as Cryptosporidium sp. and Giardia sp., and viruses). In
another significant although unexpected aspect of the invention, the process is employed in the removal of
microbial contaminants that are less than about 0.1 microns in size (e.g., viruses). Therefore, another focus of the
invention is on the treatment of wastewater containing microbial contaminants that are less than about 10 or 5
microns in size and/or microbial contaminants that are less than about 0.1 microns in size.
FIG. 1 illustrates one embodiment of a wastewater treatment system 11 that can employ a treatment process
according to the invention. The wastewater system 11 shown includes a primary-secondary treatment zone 13, a
tertiary treatment zone 15, and an effluent discharge and distribution zone 17. The wastewater system 11
receives raw wastewater 19 and discharges treated wastewater fit for discharge into the natural environment
and/or for reuse. Although the system shown and discussed below operates in a continuous manner, it should be
understood that this system, or other systems embodying the invention, may operate in a batch mode.
In the primary-secondary treatment zone 13, raw wastewater is received by a conventional primary treatment
facility 21 and acted on to remove larger solids contaminants. The primary treatment facility 21 may include a
rack and rake system or some other screening device to mechanically separate larger solids from the wastewater.
Further, the raw wastewater 19 may be received in settling ponds wherein solids can separate from the
wastewater by gravity. Raw wastewater 19 received in the primary treatment facility 21 contains, in addition to
larger solids particles, a significant amount of very fine particles suspended or dissolved in the liquid portion of
the wastewater. As discussed above, sewage wastewater and other wastewater containing organic wastes
typically contain significant concentrations of microbial contaminants less than about 30 microns in size (i.e.,
about 10.sup.6 to 10.sup.9 /100 ml). Among these will be pathogenic microorganisms less than 10 microns in
size, such as protozoans, bacteria,viruses, and some parasites. The majority of these pathogenic microorganisms
(i.e., typically up to about 10.sup.7 to 10.sup.8 /100 ml) remain in the wastewater even after primary treatment.
From the primary treatment facility 21, the primary treated wastewater is sent to a conventional secondary
treatment facility 23 to further lower the total suspended solids (TSS) and the biochemical oxygen demand
(BOD) in the wastewater and, thus, reduce the concentration of pathogenic microorganisms. A typical secondary
treatment facility 23 may include a digester, gravity settling ponds and/or a sequencing batch reactor wherein
different activated sludge processes are employed.
The primary and secondary treatments of raw wastewater typically produce effluent still containing a substantial
concentration(i.e., typically up to about 10.sup.2 to 10.sup.6 /100 ml) of microbial contaminants including
pathogenic microorganisms. The benefit of the invention is most appreciated when the effluent from the primary
and secondary treatments of raw wastewater contains in excess of about 10.sup.2 /100 ml microbial
contaminants, and more appreciated when the effluent from the primary and secondary treatment of raw
wastewater contains between about 10.sup.4/100 ml to 10.sup.6/100 ml microbial contaminants.
From the secondary treatment facility 23, the treated wastewater may be returned to the primary treatment
facility or discharged into the tertiary treatment zone 15. The tertiary treatment zone 15 depicted in FIG. 1
includes an equalization basin 25, a pre-filtering facility 27, a filter apparatus 29, and a disinfecting facility 31.
Primary-secondary treated wastewater discharged into the tertiary treatment zone 15 is first received in the
equalization basin 25. The equalization basin 25 provides for further separation of heavier solids from the liquid
portion of the wastewater and allows the primary-secondary treated wastewater to reach equilibrium.
The pre-filtering facility 27 includes an agglomeration contactor or vessel 33 that is fluidly connected on an inlet
side with the equalization basin 25, and also with a first chemical addition system 35 and a second chemical
addition system 37. The agglomeration vessel 33 is positioned between the equalization basin and the filter
apparatus 29 and can accommodate the flow or transfer of wastewater from the equalization basin 25 to the filter
apparatus 29. In the agglomeration vessel 33, generally known methods are employed to promote the
agglomeration of suspended solids in the wastewater to form suspended solids aggregates that include microbial
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&col=AND&d... 8/15
8/27/2019 United States Patent:6110374
contaminants. As will be further shown below, the effectiveness
of the filter apparatus 29 to remove such suspended solids and other microbial contaminants from the
wastewater is enhanced by promoting the agglomeration of solids prior to filtering. It should be noted, however,
that the structure of the agglomeration vessel 33 is partly dependent upon the method of agglomeration used.
In a preferred process of the invention, filter-aid agents are added to the wastewater as the wastewater is passed
through the agglomeration vessel 33. The agglomeration vessel 33 illustrated in FIG. 1 is an elongated mixing
basin 33 that is separately fluidly connected to the first and second chemical addition systems 35, 37. As will be
recognized by one skilled in the art, most known chemical addition systems will be workable in the current
system as long as such systems are capable of adding filter-aid agents to the wastewater in the agglomeration
vessel 33, 25 as needed(and when needed) to promote formation of the solids aggregates. For example, the
agglomeration vessel 33 may not be a tank or other vessel, but a section of conduit between the equalization
basin 25 and the filter apparatus through which the wastewater flows and into which filter-aid agents are added.
Other structures generally known in the art may also be used. Further, the addition of filter-aid agents into the
agglomeration vessel 33 may occur in a one step, or multi-step process, and may occur by manual or by
automated methods generally known.
FIG. 1 illustrates chemical addition systems 35, 37 which are automated, and which include a reservoir 35a, 37a
for retaining a supply of a filter-aid agent. Each chemical addition system 35, 37 also includes a conduit
interconnecting the reservoir 35a, 37a with the agglomeration vessel 33, and a pump (not shown) for selectively
transferring amounts of filter-aid agents into the agglomeration vessel 33. Further, each of the reservoirs 35a,
37a may include a static mixer(not shown) for producing a generally homogeneous mixture of filter-aid agent,
and to aid in the preparation of a filter-aid agent.
The filter-aid agents are agglomeration-promoting agents such as coagulants, flocculants, or other chemicals or
mixtures generally known to aid in the bringing together of small solid or semi-solid particles in the wastewater
and forming clumps or masses of particles that may be more effectively removed by filtration. Preferred filter-
aid agents include coagulants, flocculants, solutions or mixtures containing coagulants or flocculants, and
mixtures thereof that are generally known for use in the agglomeration of suspended solids in wastewater. The
terms coagulation and flocculation, and likewise coagulant and flocculant, are often used interchangeably, but
may be better understood if seen as two different mechanisms. More specifically, coagulants are chemicals
which de-stabilize the solids in colloidal suspension by neutralizing the repulsive forces that keep the solids
apart and allow the suspended solids to group together. Flocculants, on the other hand, are chemicals which
physically bridge between the suspended solids to help form large filterable flocs (i.e., solids aggregates). Many
coagulants known for use in wastewater treatment systems can perform both coagulant and flocculant functions
by neutralizing surface charges, and adsorbing onto more than one colloid to form a bridge between them.
Most known coagulants for use in wastewater treatment and which are not detrimental to the filtration process
are usable in the current invention. Coagulants usable in the present invention include, but are not limited to,
inorganic coagulants, including iron salts, aluminum salts, activated silica, and bentonite, and preferably
aluminum sulfate (alum). Additional usable coagulants include indifferent electrolytes, such as sodium chloride,
and organic polyelectrolytes,preferably cationic polyelectrolytes. Examples of cationic polyelectrolyte
coagulants include, but are not limited to: polyethyleneamine, quaternized polyamines, epichlorohydrin-
dimethylamine, diallydimethyl-ammononium chloride, polyethylene imine, and polyalkalene polyamine.
Most flocculants known for use in wastewater treatment are usable in the current invention as long as they are
not detrimental to the filtration process. Usable flocculants include, but are not limited to, aluminum sulfate,
lime, ferric chloride, and other iron salts, polyelectrolytes, and mixtures thereof. Usable flocculants also include,
but are not limited to, organic polymers such as cationic polyelectrolytes, anionic polyelectrolytes, and non-ionic
polymers. Examples of usable cationic polyelectrolytes include, but are not limited to,
acrylamide/diallyldimethy-lammonium chloride copolymer, acrylamide/amine copolymer, and Mannich
polymer. Examples of usable non-ionic polyectrolytes include, but are not limited to, polyacrylyamide and
polyethylene oxide. Examples of anionic polymers include hydrolyzed polyacrylamide and acrylamide/acrylate
patft.uspto.gov/netacgi/nph-Parser?Sect1=PT02&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&co 1=AND&d... 9115
a/27/2019 United States Patent: 6110374
copolymer.
Generally, the amount of filter-aid agents added to the wastewater is dependent upon many factors including: the
type of filter-aid agent used, the general wastewater chemistry, the amount of total suspended solids in the
wastewater, the flow rate of the wastewater through the agglomeration vessel 33, and other factors appreciated
by those skilled in the art. Agglomeration of suspended solids in wastewater using coagulants and flocculants is
generally known by those skilled in the art, and known methods and dosages of adding coagulants and
flocculants to the wastewater are usable in the current invention.
In a preferred process of the invention as illustrated in FIG. 1, two distinct filter-aid agents or mixtures of filter-
aid agents are added to the wastewater in the agglomeration vessel 33: a first filter-aid agent that acts primarily
as a coagulant, and a second filter-aid agent that acts primarily as a flocculant. The first filter-aid agent is added
to the agglomeration vessel 33 by the first chemical addition system 35, and the second filter aid agent is added
to the agglomeration vessel 33 by the second chemical addition system 37. In a more preferred embodiment, the
first filter-aid agent is granular aluminum sulfate (alum). The alum is preferably put into an aqueous mixture for
ease of addition into the wastewater. The first filter-aid solution is preferably added to the agglomeration vessel
33 such that it is present in a concentration of between about 2 mg and about 10 mg(2 to 10 ppm) per liter of
wastewater flowing through the agglomeration vessel 33, and more preferably about 10 mg/L of wastewater(10
ppm). The second filter-aid chemical is preferably an organic polymer flocculants such as a mixture
commercially available under the trademark Cytec Superfloc A-130. The second filter-aid chemical is preferably
put into an aqueous mixture for ease of addition into the wastewater. The second filter-aid agent is added to the
agglomeration vessel 33 at a rate such that between about 0.5 mg and about 3 mg (0.5 to 3 ppm) of the second
filter-aid agent is added per liter of wastewater flowing through the agglomeration vessel 33, and more
preferably about 1 mg/L (1 ppm).
In adding the filter-aid agents to the agglomeration vessel 33, it is advantageous to thoroughly mix the filter-aid
agents with the wastewater. In this regard, it may be advantageous to use a mixing apparatus in the
agglomeration vessel 33, such as a static mixer, a turbine or propeller type impeller, or the like. Preferably, the
agglomeration vessel 33 is a complete mixing basin or a reaction basin having close to an ideal plug flow or
constant flow. Moreover, the contact time or residence time of each of the filter-aid agents with the wastewater
in the agglomeration vessel 33 should be sufficient to allow for the desired agglomeration effect. In a preferred
embodiment, the average contact time of the coagulant is about 0.5 to about 3 minutes (preferably about 2
minutes), and the average contact time of the flocculant is between about 0.5 to about 2 minutes (preferably
about 1 minute).
The tertiary treatment zone 15 further includes one or more filter apparatus 29 through which wastewater from
the pre-filtering zone is passed to separate or remove the solids aggregates and other fine particles from the
wastewater stream. Referring to FIGS. 2 and 3, the filter apparatus 29 may include a filter tank 113 having an
influent inlet 115 and an effluent outlet 117, and a plurality of rotatable filter disks 119 disposed between the
influent inlet 115 and the effluent outlet 117. Each of the filter disks 119 supports filter media, membrane or
material 121 through which the influent wastewater is passed. The filter apparatus 29 depicted in FIGS. 2 and 3
includes four filter disks 119, but the filter tank 113 may be sized, in alternative embodiments, to hold more than
four filter disks 119 or fewer filter disks 119, depending on the particular filtering demand of the wastewater
treatment process.
Referring to FIG. 2, the filter disks 119 are generally vertically disposed and spaced apart in parallel relation.
The filter disks 119 are supported by, and fixed to, a horizontally disposed hollow drum 125 that is supported for
rotation about its central longitudinal axis by a mounting assembly 123. The mounting assembly 123 is
comprised of at least three rollers 127 which engage an outer surface of the hollow drum 125 and allow the
hollow drum 125 and the filter disks 119 to be rotated about a horizontal central longitudinal axis of the drum
125. A sprocket 131 encircles the hollow drum 125, and a chain drive 133 drivingly engages the sprocket 131.
The chain drive 133 is adapted to be driven by a motor assembly 137 for rotating the hollow drum 125 and filter
disks 119.
patft.uspto.gov/netacgiinph-Parser?Sect1=PT02&Sect2=H ITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&col=AND&... 10/15
8/27/2019 United States Patent:6110374
The filter tank 113 is formed by a hoppered bottom 143, upwardly extending side walls 145, and an open top
141. A first drain outlet(not shown) is provided near the bottom 143 and is operable to remove solids
accumulation from the tank 113. A second drain outlet(not shown) is positioned in one of the side walls 145 and
is operable to lower the liquid level in the tank 113. The filter tank 113 further includes an influent chamber 157
defined by the liquid retaining space inside the filter tank 113 that is outside of the material 121 and four effluent
chambers 153 defined by the spaces within or partially enclosed by the filter material 121. As depicted in FIG. 2,
each filter disk 119 has a pair of outer surfaces or influent surfaces 159 which face the influent chamber 157, and
a pair of parallel spaced apart inner surfaces or effluent surfaces 161 which face the effluent chamber 153.
The filter disks 119 are preferably formed by a plurality of removable filter sectors 171 that are mounted about
the hollow drum 125. Each filter sector 171 includes a grid-type frame 173 which supports the filter material
121. Preferably, the filter cloth material 121 is in the form of a bag that is fitted over, and supported by, the grid
frame 173. Referring to FIG. 4, the filter cloth material 121 is preferably made of one or more layers of two to
six mm thick needled polyester felt. Each layer may be formed by conventional means, for example, by pressing
50 cm thick polyester fabric comprised of very fine fiber particles about 50 microns or less in diameter and then
needling the pressed fabric to reorient fiber particles in the vertical or transverse direction. A supporting weave
175 is arranged in the middle of the layer. As a result of the needled felt process, the polyester fibers form a
multi-layer random web structure lacking in consistent straight-through or transversely disposed pores between
adjacent fibers. The needled polyester felt filter material 121 has an average free (or unencumbered)passage
between polyester fibers and through the filter material 121. Preferably, the free passage of the filter material
121 is in the range of about 5 microns to 10 microns,while the space percentage of the solid particles in the filter
material 121, including the polyester fiber, amounts to about ten to fifteen percent.
Suitable Filter disks 119 equipped with filter material 121 having an average free passage or flow through size of
5 microns for use in the present invention is commercially available from Aqua-Aerobic Systems, Inc. of
Rockford, Ill. under the designation Filter Disk 101. Suitable filter disks 119 including filter material 121 having
an average free passage or flow through size of 10 microns for use in the present invention is also commercially
available from Aqua-Aerobic Systems, Inc. under the designation Filter Disk 102.
Wastewater containing suspended solids aggregates formed in the pre-filtering zone, including microbial
contaminants, may be supplied to the filter tank 113 by gravity feed or by a pump (not shown)through an
influent supply line 163. The wastewater enters the influent chamber 157 and then passes through the filter
material 121 of the filter disks 119. As the wastewater stream passes through the filter material 121, the path of
suspended solids is hindered by polyester fibers in the web structure causing the solids to be caught in between
adjacent fibers or to adhere to the fibers themselves. Due to the random web structure of the filter material 121,
individual flowlines in the stream carrying the suspended solids will typically deviate from a straight-through
path through the filter material 121, thereby increasing the chances of the suspended solids (i.e., the solids
aggregates) being caught in the filter material 121, regardless of the size of the solids.
The filter material 121, in combination with the process of the present invention, is capable of separating a
greater amount of pathogenic microorganisms than has previously been accomplished with other wastewater
filtration techniques. More specifically, the process according to the invention which includes the steps of
promoting the agglomeration of suspended solids in a reference volume of wastewater and passing the
wastewater, including the solids aggregates formed therein through the filter material, removes greater than
about 50% of microbial contaminants, including pathogenic microorganisms, from the reference volume of
wastewater. Preferably, the process removes greater than 90%, more preferably greater than 99%, and most
preferably, greater than 99.9% of microbial contaminants, including pathogenic microorganisms, from the
reference volume of wastewater.
In a significant aspect of the present invention, the process removes microbial contaminants that are less than
about 10 microns in size, and, alternatively, microbial contaminants that are less than about 5 microns in size.
Preferably, the process removes greater than about 50% of microbial contaminants that are less than about 10
microns or less than about 5 microns in size from the reference volume of wastewater. More preferably, the
process removes greater than about 90%, more preferably greater than about 99%, and most preferably, greater
patft.uspto.gov/netacgi/nph-Parser?Sect1=PT02&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-boot.html&r=3&f=G&I=50&co 1=AND&... 11/15
8127/2019 United States Patent:6110374
than about 99.9% of microbial contaminants that are less than about 10 or 5 microns in size from the reference
volume of wastewater.
In another significant, and unexpected aspect of the invention, the treatment process removes microbial
contaminants that are less than about 0.1 microns in size. Preferably, the process according to the invention
removes greater than about 50% of microbial contaminants that are less than about 0.1 microns in size from the
reference volume of wastewater. More preferably, the invention removes greater than 90%, and most preferably
greater than 99% of microbial contaminants that are less than about 0.1 microns in size from the reference
volume of wastewater.
The reference volume of wastewater may also contain a substantial concentration of pathogenic microorganisms
(e.g.,protozoans, bacteria, and viruses) that are less than about 5 microns in size. In such cases, the process
according to the invention separates greater than about 50%, greater than about 90%, and even greater than
99.9% of such pathogenic microorganisms from the reference volume of wastewater.
Further, the volume of wastewater may contain a substantial concentration of pathogenic microorganisms less
than about 0.1 microns in size, including,but not limited to viruses, and the process according to the invention
separates greater than about 50%, greater than about 90%, greater than about 99%, and even greater than 99.9%
of such pathogenic microorganisms from the volume of wastewater.
In more specific terms, the reference volume of wastewater may contain protozoan pathogens including
Cryptosporidium sp. and Giardia sp., and the step of passing the volume of wastewater(including the solid
aggregates) through the filter membrane may separate greater than about 50%, more preferably greater than
about 90%, and more preferably greater than 99.9% of the Cryptosporidium sp. and Giardia sp. from the
reference volume of wastewater. The wastewater may also contain viruses, and the step of passing the volume of
wastewater through the filter membrane may separate greater than about 50%, more preferably greater than
about 90%, and more preferably greater than about 99.9% of the viruses from the reference
volume of wastewater.
The removal or reduction rates described above may be achieved using a process preferably employing a
needled polyester felt filter material 121 having an average free passage size of 5 microns, or greater than 5
microns (i.e., 10 microns). Moreover, such removal or reduction rates may be achieved using a process wherein
the wastewater is passed at least once or a greater number of times through the filter material 121.
It is common in the art of wastewater treatment to refer to removal or reduction of microbial populations in
terms of log removal rather than in percent removal. The following Table 1 represents a conversion of percent
removal into terms of log removal, and gives examples of populations that remain after a certain log removal
occurs upon an initial population of microorganisms.
TABLE 1 Log Percent Initial Population of Microorganisms
Removal Removal 100 1,000 100,000 1,000,000 1 90 10 100
10,000 100,000 2 99 1 10 1,000 10,000 3 99.9 0.1 1.0 100 1,000 4 99.99 0.01 0.1 10 100 5 99.999 0.001 0.01 1
10 6 99.9999 0.0001 0.001 0.1 1
The use of the present invention to treat wastewater having a significant initial concentration of microbial
contaminants preferably results in at least one log reduction in the amount of microbial contaminants in the
wastewater. More preferably, a log reduction of 2, and more preferably, a log reduction of 3 is obtained.
Additionally, the use of the present invention also preferably results in at least one log reduction in the amount
of microbial contaminants that are less than about 5 microns in size, and more preferably a log reduction of at
least 2 or 3 is obtained for microbial contaminants that are less than about 5 microns in size. Additionally, the
use of the present invention also preferably results in at least one log reduction in the amount of microbial
contaminants that are less than about 0.1 microns in size, and more preferably, a log reduction of at least 2 is
obtained for microbial contaminants that are less than about 0.1 microns in size.
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=MTOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&col=AND&... 12/15
8/27/2019 United States Patent 6110374
After passing through the filter material 121, the filtered wastewater flows into the effluent chamber 153 and
then into hollow drum 125. From the hollow drum 125, the filtered wastewater flows into a rising conduit 167
and out of the filter tank 113 through the effluent outlet 117. The effluent outlet 117 is typically positioned at a
level adjacent the uppermost portions of the filter disks 119.
The filter disks 119 may be cleaned periodically of filtered solids and biogrowth on the filter material 121 using
either a backwash system or a spray wash system. The backwash system includes a backwash pump 172, suction
piping 195 and a plurality of suction heads 177 positioned nearly adjacent the influent surfaces of the filter
material. During a backwash operation, the suction heads 177 engage the influent surfaces 159 of the filter
material 121 such that the flexible filter material 121 conforms to the suction heads 177 and draw filtered water
from the effluent chambers 157 through the filter material 121 in a direction reverse of the normal filtering
direction. The resulting backwash stream removes the filtered solids (including microbial contaminants) from
the filter material 121 and carries the dislodged solids with backwash water to a discharge conduit(not shown)
for discharge at a location (not shown) external of the filter tank 113. Meanwhile, the filter disks are rotated by
energizing motor 137 and driving sprocket 131 through drive chain 133. In this manner, essentially all of the
influent surfaces 159 of the filter material 121 is brought into contact with the suction heads 177.
The spray wash system includes a high-pressure pump (not shown) connected to four pairs of spray nozzles or
nozzle heads 185. Each nozzle head 185 is positioned nearly adjacent the influent surface 159 of the filter
material 121. When actuated, the high-pressure pump delivers a liquid stream at high pressure to each of the
nozzle heads 185 and each nozzle head 185 directs a high velocity liquid stream against the influent surface 159
of the filter material 121. The liquid stream acts to wash the influent surface 159 and to remove solids and other
fine particles including microbial contaminants that accumulate thereon. The liquid stream also penetrates the
influent surface 159 to impact and dislodge filtered solids entrained within the filter material 121. In an
alternative arrangement, the nozzle heads 185 can be positioned inside the effluent chambers 157 to direct liquid
streams in opposite directions against portions of the effluent surfaces 161.
Other aspects of the filter apparatus 29 and their operation are also discussed in U.S. Pat. Nos. 5,362,401 and
5,374,360, both of which are assigned to the assignee of the present invention. U.S. Pat. Nos. 5,362,401 and
5,374,360 are hereby incorporated by reference.
In many treatment systems,before leaving the treatment facility, the treated wastewater is disinfected using a
disinfecting agent such as chlorine. In this regard, it is advantageous to remove as much of the suspended solids
prior to chlorine treatment since the solids tend to absorb chlorine and, thus, increases the amount of chlorine
required for disinfection. Over-chlorination is not only expensive but can be harmful to the environment when
chlorine is discharged at high levels.
Referring to FIG. 1, in the embodiment shown, the effluent or filtrate discharged from the filter apparatus is sent
to a conventional disinfecting facility 31. Typically, the disinfecting facility 31 will include a chlorination tank
41 wherein chlorine is added to the filtrate for sterilization. Due to the effectiveness of the filtration process
according to the invention, the filtrate contains a minimal concentration of total suspended solids, and therefore
does not adsorb 25 as much of the chlorine as in prior art processes. Accordingly, the process requires only a
minimal amount of chlorine to disinfect a volume of wastewater. After the wastewater is treated in the
disinfection system, it is discharged by a discharge and distribution system as conventionally known.
The discharge and distribution system may simply entail discharging the treated water from the disinfection
system 41 through a conduit directly into the environment, such as into a pond, lake, river, or simply onto the
ground. Other discharge systems, such as leach fields 45, perforated piping, evaporation basins 47, or other
systems generally known may be used.
The following examples are intended to exemplify embodiments of the invention and are not to be construed as
limitations thereof.
patft.uspto.gov/netacgi/nph-Parser?Sect1=PT02&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&l=50&co1=AND&... 13115
8/27/2019 United States Patent:6110374
EXAMPLE
A series of test examples were performed to evaluate the removal of enteric viruses and protozoan parasites
using a treatment system embodying the current invention. A bench scale filter apparatus including a needled
polyester felt filter membrane was set up and tested for its ability to remove microbial contaminants from
wastewater. The filter apparatus used comprised an elongated tube having upper tube portion and a lower tube
portion which were separated by a needled polyester felt filter membrane. The filter membrane was supported by
a support ring.
A volume of wastewater was prepared and passed through the filter apparatus. In particular, a sample volume of
wastewater was obtained from the Roger Road sewage treatment plant in Tucson, Ariz.. The Tucson plant treats
domestic sewage by a combination of activated sludge and biotowers. The sample volume of wastewater was
secondary effluent collected after the clarifiers and before disinfection in the Tuscon plant.
Because of the usually low concentration of viruses in secondary sewage and the difficulty in measuring such
low concentrations, vaccine strain coliphage MS-2 was added to the wastewater in the influent mixing tank to a
concentration of approximately 10.sup.7 /liter in a five-gallon sample volume of the wastewater. The MS-2
coliphage was grown and assayed in Escherichia coli ATCC 15597 by the PFU method. It is of a similar shape
and size to poliovirus and has been used in numerous studies to evaluate water and wastewater treatment.
Further, it is often used to evaluate filtration devices because of its poor absorption to surfaces and, thus, is
considered a "worst case" model of virus removal by filtration.
Giardia cysts are usually present in secondary sewage at concentrations ranging from 50-200/liter and
Cryptosporidium oocysts at concentrations of 10-50/liter which are great enough concentrations to be detected in
1-2 liter sample volumes. Enough Giardia cysts were present in the wastewater to assess a 99% removal by the
filters. However, a lower level of Cryptosporidium oocysts required that they be added to better assess filter
performance. Live Cryptosporidium oocysts were obtained from infected calves and purified by density gradient
centrifugation in sucrose. The purified Cryptosporidium oocyst were then added to the wastewater before
filtration or addition of the filter-aid agents producing substance.
A series of four tests were run using this system wherein a volume of wastewater was prepared and passed
through the filter apparatus by gravity feed from the upper tube portion to the lower tube portion. In each test,
the concentration of certain microbial contaminants in the influent and the effluent were measured and
compared.
In the first series of tests, Filter Type 101 having a 5 micron flow through or free passage size was used on the
filter apparatus, and no filter aid agents were used. In the second series of tests, Filter Type 101 was again used,
but filter-aid agents (FAA) including an alum coagulation agent was added to the wastewater at a concentration
of about 10 ppm, for a contact time of about 2 minutes. Then, an organic polymer flocculant was added to the
wastewater at a concentration of about 1 ppm for a contact time of about 1 minute.
In the third series of tests, Filter Type 102 having a 10 micron flow through or free passage size was used on the
filter apparatus, and no filter-aid agents were used. In the fourth series of tests, Filter Type 102 was used, and
filter aid agents including an alum coagulation agent was added to the wastewater at a concentration of about 10
ppm, for a contact time of about 2 minutes. Then, an organic polymer flocculant was added to the wastewater at
a concentration of about 1 ppm for a contact time of about 1 minute.
In each series of test runs, 10 ml samples for coliphage analyses were collected before and after filtration and
compared to determine removal of the viruses by the filter system. Removal of Giardia sp. cysts and
Cryptosporidium sp. oocysts was determined by direct assay of the wastewater before and after filtration. One
liter samples before and after filtration were collected and centrifuged for 10 minutes at 1,400.times.g to pellet
the cysts and oocysts. The organisms were resuspended in 10 ml of distilled water containing 0.1% Tween 80.
They were then passed through membrane filters and stained with fluorescent labeled monoclonal antibodies and
examined under a UV light microscope as described in the Manual of Environmental Microbiology for the
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&col=AND&... 14/15
$(27/2019 United States Patent:6110374
presence of oocysts and cysts.
The following tables illustrate the results of the series of testing, indicating the performance of the current
invention to remove microbial contaminants from wastewater. The Filter Type column indicates the type of filter
material used, wherein 101 indicates a filter material on a filter disk(s) commercially available from Aqua-
Aerobics Systems, Inc. (discussed previously) and 102 indicates a filter disc(s) also commercially available from
Aqua-Aerobics Systems, Inc. (also discussed previously). The Filter Type column also indicates whether a filter
aid agent (FAA) was used wherein "with FAA" indicates the use of a filter aid agent, and "no FAA" indicates
that no filter aid agent was used. The remaining columns indicate the influent and effluent concentration of the
relevant microbial contaminant being measured, and the percent reduction obtained.
Percent Filter Type Influent Effluent Reduction
Cryptosporidium Reduction Results are given as oocysts/mL
101 FAA 8.69.10.sup.3 13 99.85 101 No FAA 9.21 .times. 10.sup.4 8.65 .times. 10.sup.3 90.61 102 FAA 5.36
.times. 10.sup.3 11.1 99.79 102 No FAA 2.09 .times. 10.sup.6 5.75 .times. 10.sup.3 99.72 Giardia Reduction
Results are given as oocyst/mL 101 FAA 2.29 .times. 10.sup.3 <1 >99.9 101 No FAA 3.34 .times. 10.sup.2 17
94.91 102 FAA 2.29 .times. 10.sup.3 2.1 99.9 102 No FAA Giardia 3.75 .times. 10.sup.2 19 94.93 MS-2
Reduction in Wastewater Results are given as PFU/mL 101 With FAA 1.89 .times. 10.sup.6 3.38 .times. 10.sup.4
98.21 101 No FAA 2.33 .times. 10.sup.6 1.92 .times. 10.sup.6 17.17 102 With FAA 1.89 .times. 10.sup.6 1.29
.times. 10.sup.4 99.32 102 No FAA 1.61 .times. 10.sup.6 1.83 .times. 10.sup.6 No Reduction
While some embodiments of the invention are shown in the drawings and discussed above, alternate
embodiments will be apparent to those skilled in the art and are within the intended scope of the present
invention. Therefore, the invention is to be limited only by the following claims:
Images
View Cart]
J Add to Cart
Hit List Previous Next Top
•
Home Quick Advanced Pat Num J Help I
patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3&f=G&I=50&col=AND&... 15/15