AWWA ACE63243

This slide presentation outlines a pilot testing study on pretreatment for seawater desalination. A case study located in Southeast Asia is outlined. Background information of the case study includes: highly variable estuarial water; three parallel pretreatment trains; Zenon Ultrafiltration; Norit Ultrafiltration; two-stage granular media filtration; coagulation and pH adjustment prior to each pretreatment train; and, each pretreatment system feeds three parallel RO systems. GMF study objectives are listed, along with SDI and turbidity performance results for Zenon ultrafiltration, Norit ultrafiltration, and GMF, the GMF optimization test plan, jar testing coagulant aids, operating parameters, and coagulation results at pilot scale. Conclusions on general impacts included: increased chemical consumption; increased solids loading onto the filters reduces filter run times; since re-bedding and coagulation changes, pretreatment by GMF has demonstrated performance comparable to ultrafiltration; turbidity, SDI, iron levels; additional operator attention and process control may be needed compared with membranes; and, sedimentation may assist performance reliability. Includes tables, figures.