[Optimal process combination for control of disinfection by-products and precursors during high algae laden period].

Traditional pre-chlorination process would lead to high yield of DBPs during high algae laden period. It had been compared that the efficiency of control disinfection by-products and their precursors by two classes and total 7 kinds of process combination. Algae were proven to be important DBP precursor and it contributed about 20% of HAA and THM precursor. Air floatation was key process to remove algae and it could also reduce the precursor concentration in some degree. Ozone or potassium permanganate also had good efficiency on algae removal, and precursor as well. The best process combination for DBPs and their precursor removal is pre-oxidation of ozone or potassium permanganate plus conventional process plus ozone-BAC process. Sequential chlorination can reduce 42.0%-45.9% HAA yield and 22.5%-71.4% THM yield of free chlorination.