AWWA ACE61727

This paper discusses hydraulic and water qualityperformance data gathered during a six-month pilot study in Kansas City which demonstrates thatretrofitting granular media filters with low-pressure membranes in large plants can be an important tool tomeet ever-increasing regulatory requirements while substantially increasing plant capacity. Specific objectives ofthe project were to:develop full-scale membrane system design for retrofitting the Kansas City Water ServicesDepartment (KCWSD) water treatment plant with membranes selected for specific characteristics thatmake them well suited for the application, including high permeability, high fiberpacking density, and chemical compatibility;develop conceptual layouts detailing both gravity-fed and pumped membrane retrofit scenarios atKCWSD based on the design parameters developed during pilot testing, including ananalysis of integration issues such as the use of existing infrastructure, ancillary equipmentrequirements, membrane integrity testing protocols, and operator training requirements; and,develop cost estimates for retrofitting existing granular media filters with membrane media filters atthe KCWSD water treatment plant. Membrane pilot testing was conducted at KCWSD's 240-million gallon per day (mgd) lime softeningplant, which draws water from the Missouri River. Three low-pressure membranes were pilot-tested at KCWSD: Hydranautics UF Hydracap 60 (INDECK)2;Polymem UF 120S3 (WESTECH)2; and, Zenon ZW-1000 (ZENON)2. The three membranes were chosenbecause they encompass two membrane system alternatives that may be particularly suitable for retrofitdesigns: submerged membrane systems; and, custom designed, pressurized vessel membranesystems. The pressure driven systems were evaluated under low flux, low feed pressure conditions that wouldpermit their operation within the existing hydraulic grade line at the plant. All three membrane systemswere then evaluated under high flux, high feed pressure, or permeate vacuum conditions to maximizecapacity of the membrane modules and to establish design parameters for a pumped scenario. Threeoperational criteria were maintained throughout pilot testing:clean-in-place (CIP) interval e 30 days;recovery e 90 percent; and,total chlorine concentration in the backwash wastewater d 2 milligrams per liter (mg/L) greater thanthe feed concentration. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/17/2005

Number of Pages:

10

File Size:

1 file , 470 KB