Performance of outside-in pressurized ultrafi ltration in the Qingdao Pilot tests

Abstract

ab s t r ac tA new seawater desalination plant (SWDP) is to be built in Qingdao, China by Befesa Agua, S.A.U. The application of SWDP is to produce drinking water for local residents due to lack of brackish water in north China. Seawater will be treated with membrane technologies to achieve the required water quality. The key process unit operations are ultrafiltration and seawater reverse osmosis. In order to prepare for the detailed design phase and membrane selection, a pilot study was carried out, in which various ultrafiltration product and process concepts were investigated. Among other, submerged and pressurized processes were tested, using inside-out and outside in module configurations, polyethersulfone (PES) and polyvinylidene fl uoride (PVDF) fibers. Comparative results with these different technologies had been published previously. This publication provides detailed results on the first phase of testing of one of the technologies investigated: pressurized, outside-in, PVDF-based ultrafi ltration product and process. It shows performance both from a hydraulic point of view as well as the water quality characterization.

Development of an Environmental Impact Assessment and Decision Support System for Seawater Desalination Plants

“…Doses are slightly higher with 15-20 mg/l but CEB is slightly less frequent with once every 30-60 minutes. A dose of 500 mg/l once or twice per day has also been reported [86,101,102]. One full-scale Dow plant operated without any CEB [87].…”

“…Chlorine levels in CEB varied between 5-20 mg/l every 15-40 minutes [i.e., every backwash, 98,99,101,119,123], to 20-50 mg/l every 2-6 hours [112,117], up to 100-500 mg/l once or twice per day [98,100,102,107,110,120,121]. These values show a higher upper range than the results of a review carried out by Fritzmann et al [126], who reported chlorine levels of 10-200 mg/l in CEB of UF/MF membranes.…”