TREATMENT OF PHOTOGRAPHIC WASTE LIQUID

摘要

PURPOSE:To efficiently lower COD value and BOD value by previously oxidizing and decomposing the photographic waste liquid wherein the concn. of bromide ions is >=0.1g/l and BOD/COD value is <=1.0 by iron powder and aqueous hydrogen peroxide and thereafter performing biological treatment. CONSTITUTION:The pH of the photographic waste liquid wherein the concn. of bromide ions is >=0.1g/l and BOD/COD value is <=1.0 is preferably regulated to about 7 or below. After iron powder is added thereto and the mixture is agitated, hydrogen peroxide is continuously added at about 5ml-5l per waste liquid 1l to oxidize the waste liquid. After oxidative reaction is completed, an alkali agent is added to regulate the pH to about 6.5 or more and the mixture is agitated for a specified time. Thereafter a polymeric flocculant is added and suspended solid is flocculated and settled and thereafter this ppt. is filtered and separated. Then biological treatment such as activated sludge treatment is performed and thereby clarified water wherein COD and BOD are lowered can be obtained.