Synchronization of dehydration and phosphorous immobilization for river sediment by calcified polyferric sulfate pretreatment.

Abstract Disposal of dredged river sediment requires decreases in both water content for reduction in disposal area, and the amount of eutrophication pollutants at risking of leaching. The effects of CaCl2, polyferric sulfate (PFS) and calcified polyferric sulfate (CaPFS) on dewatering and phosphorus immobilization were examined. Upon CaPFS dosage of 1.88 mg Ca + Fe kg−1 raw sediment (RS) the moisture content of the sediment was 41.1 wt% after pressure filtration, with filtrate dissolved inorganic phosphorus (DIP) of 6.1 mg L−1; better outcomes than for equivalent dosages of CaCl2 or PFS. On CaPFS dosage of 4.98 mg Ca + Fe kg−1 RS, DIP in the filtrate was