FOG VERSUS MEMBRANES = ? (SOME GOOD NEWS)

摘要

MDWASD is in the process of implementing of one of the largest High Level Disinfection Programs in the country (285-mgd peak hour with an annual average flowrate of 112.5 mgd). In addition to the in- stallation of deep bed filters and chlorination facilities for high level disinfection, secondary treatment process upgrades and related improvements are being implemented to enhance the reliability of treat- ment upstream of the HLD system and thereby minimize the potential for filter plugging and the result- ing loss of service of the HLD system. The MDWASD SDWWTP has unique Fats, Oils and Grease (FOG) problems related to clogging and aesthetics concerns as well as the presence of very fine and dis- persed FOG in its secondary effluent. Based upon significant concerns for impacts of FOG levels on the existing secondary WWTP and concerns for clogging of 30 planned, large deep bed filters with a capaci- ty rating of 285 mgd, an intensive field sampling, testing and evaluation program for FOG sources and treatment options was completed. The resulting secondary WWTP FOG removal upgrades are currently under construction.