Study on the comparison between ultrafiltration pretreatment without any chemicals and with coagulation in seawater desalination

According to the characteristics of water quality in Tianjin Bohai Bay, ultrafiltration (UF) pretreatments prior to SWRO without any chemicals and with coagulation were studied. Under the same operational and cleaning conditions, two pilot tests were discussed through monitoring and analyzing water quality, assessment of flux and transmembrane pressure. The study showed that both of the UF pretreatment processes could enable the reverse osmosis (RO) pilot plant to run steadily. But, UF pretreatment without any chemicals had a simpler process, lower investment and operation cost. At the same time, no chemical was injected into the system, so there was no membrane fouling caused by the addition of coagulation. It could be concluded that UF pretreatment without any chemicals had better applicable value and application prospects.