Study On The Treatment Of Active Dyestuff Wastewater By Pretreatment Pulse Electrocagulation System

Recently with the development of dying industry, dyestuff is progressing for being antioxidant and resist-light. And the wastewater during the producing of dyestuff is more difficult to be treated. The emission control regulations will change stricter after the people's consciousness of protecting environment become improved. The kind of wastewater, including so much organic matter and high percent salt, has become one of the most important and difficult problems. The Biology treat methods are noneffective for this kind of wastewater. It has remarkable treatment effect on the wastewater of B-active dyestuff by high voltage electrocagulation system. And conclusions as below are arrived:1. PH,reaction-time,electricity consistency are the three primary factors for reducing percent of contamination2. PH:4.60～5.60, electricity consistency is bigger than 6A, reaction-time is longer than 45 minutes, 6BF,B-2GLN and mixed wastewater's COD reduced percent are all from 65%～75%. If adding Fenton reagent before the reaction, it can improve the reduced COD about 15% efficaciously. The three kinds of wastewater after being treated by the method can meet the third class emission control regulations (COD<1000mg/L) according to GB8978-1996. 6BF wastewater's COD can arrive at 398mg/L after being treated.3. Aniline matter's decreasing is mainly relative to the change of pH. If being electrolyzed directly, the wastewater's aniline is all above 30mg/L at the best conditions. If adding the Fenton reagent, only 6BF wastewater's aniline can decrease below 5 mg/L. Adding Fenton reagent may reduce the aniline concentration of wastewater at last4. During the course of electrolysis, all over electrolyte of the wastewater alters a little. The amount of iron ion is relative to how much COD reduced. Colloid in virtue of iron not only absorbs organic matter but also produces some steady compounds with [Cl-]5. The cost of treating B-active dyestuff wastewater by pretreatment and high voltage electrocagulation system is about 5.72yuan/t. The technics is easily handled and can get good effects. The cost is reasonable. 6. The wastewater's COD can arrive below 1000mg/L by pretreatment and high voltage electrocagulation system. The wastewater's COD concentration,salt percent,aniline mater concentration are all reduced(<100mg/L) by the technique. It creates better qualification for the second biology treatment.