Treatment of linear alkylbenzene sulfonate (LAS) wastewater by internal electrolysis biological contact oxidation process

摘要

Surfactant wastewater is usually difficult to treat due to its toxicity and poor biodegradability.nA separate physico-chemical or biochemical treatment method achieves a satisfactory effect withndifficulty. In this study, treatment of the wastewater collected from a daily chemical plant by thencombination processes of Fe/C internal electrolysis and biological contact oxidation wasninvestigated. For the internal electrolysis process, the optimal conditions were: pH ¼ 4–5, Fe/C¼ (10–n15):1, air–water ratio ¼ (10–20):1 and hydraulic retention time (HRT)¼ 2 h. For the biological contactnoxidation process, the optimal conditions were: HRT ¼ 12 h, DO ¼ 4.0–5.0 mg/L. Treated by the abovencombined processes, the effluent could meet the I-grade criteria specified in Integrated WastewaternDischarge Standard of China (GB 8978-1996). The results provide valuable information for full-scalenlinear alkylbenzene sulfonate wastewater treatment.