UTILIZING A NOVEL TMP BALANCE APPROACH TO ANALYZE PROCESS DATA AND INVESTIGATE ULTRAFILTRATION MEMBRANE FOULING DURING SURFACE WATER TREATMENT

摘要

Membrane fouling is a limiting factor for the operation of ultrafiltration (UF) processes insurface water treatment, and fouling management is critical for the successful integration of UFtechnology into water treatment strategies. In practice, membrane fouling is managed through theselection of pretreatment processes, sustainable operating flux values, and effective maintenanceprotocols. These operating decisions are based, in part, on the analysis and interpretation ofprocess data. This paper demonstrates how a new data analysis approach, termed thetransmembrane pressure (TMP) balance, may be used to improve process data interpretation andfacilitate operating decisions. The usefulness of the TMP balance approach is demonstratedusing UF pilot study data collected at the Mission San Jose Water Treatment Plant (Fremont,Calif.), which practices ferric chloride coagulation and treats water from the Sacramento Delta.Significant fouling was observed during testing that necessitated a number of operationalchanges to achieve sustainable performance. One focus of the investigation was to experimentwith a variety of cleaning chemicals, including the alternative cleaning chemical acetic acid.These cleaning protocol strategies proved ineffective at recovering fiber performance, and theresults of the subsequent autopsy are discussed and correlated to observational and process data.Subsequent to the membrane autopsy, sustainable UF performance was achieved by altering thebackwash protocol and testing a membrane module with identical fiber chemistry but shorterfiber length.