WASTE WATER TREATMENT METHOD FOR REDUCING CHLORINE CONTENT IN TREATED SLUDGE

摘要

PROBLEM TO BE SOLVED: To lower the concentration of the chlorine contained in the treated sludge obtained by treating an iron chloride-containing solution containing ferrous ions, for example, a waste etching acid to a sufficiently lower level at which the recycling of the treated sludge is made possible in a cement factory or iron works. SOLUTION: The treatment method for the iron chloride-containing solution containing ferrous ions has a hydroxide treatment process step of forming a hydroxide by adding an alkaline agent to the solution and an oxidation treatment process step of oxidizing the ferrous ions in the solution to ferric ions prior to a separating and cleaning process step of subjecting the slurry of the formed hydroxide to a solid-liquid separation and cleaning the solid content thereof with water.