Application of Submerged Ultrafiltration in Pretreatment of Flue Gas Desulfurization Wastewater

Nowadays, the zero liquid discharge of flue gas desulfurization (FGD) wastewater from coal-fired units has attracted attention all countries in world. The pretreatment methods generally have problems high operation cost, small treatment capacity, and poor flexibility. However, membrane method can avoid above problems. In current research, it not been found that someone directly uses submerged ultrafiltration to pretreat FGD wastewater. Therefore, this paper innovatively proposed use ceramic treat wastewater, which ensure effluent quality improve flexibility system. paper, performance for filtration a power plant was studied optimize quality. effects operating parameters such as permeate flux, aeration rate filtration/backwashing time combination on were studied. results showed when 15 min/30 s, with increased flux 55 L/(m2·h) 100 L/(m2·h), steady transmembrane pressure (TMP) 39 kPa 70 kPa, fouling significantly 4.5 kPa/h 7.3 kPa/h; When 10 m3/(m2·h) 30 m3/(m2·h), pollution much reduced. Excessive cannot further alleviate pollution, but also brought greater energy consumption; Increasing backwashing effectively inhibit formation gel layer surface prolong initial stage low-pressure operation; rejection suspended solids (SS) turbidity equipment reach more than 99% under various working conditions, satisfy water requirements subsequent steps. suitable because premise long-term operation.