Study on Advanced Treatment of Alkali Dyeing Wastewater by Continuous Process of Iron Carbon Micro-Electrolysis-UASB-SBR

Abstract

By use of iron-carbon micro-electrolysis-UASB-SBR continuous process, treatment of an actual alkali dyeing wastewater (pH 11.50~13.50) taken from a certain factory in Xian-Yang was studied. The results indicated that: (1) When the influent COD is 1000~1600 mg·L-1, chroma 250 times, firstly effluent COD reduced to 400~800 mg·L-1and chroma 40 times by iron-carbon micro-electrolysis process, secondly effluent COD dropped to 250~500 mg·L-1by UASB process, finally effluent COD dropped to 70~98 mg·L-1by a SBR with loading PVA micro-gel beads, which meet the direct emission limits of water pollutants for dyeing and finishing of textile industry (GB 4287-2012); (2) Effective combination process of iron-carbon micro-electrolysis with UASB-SBR can be obtained through HRT optimization of micro-electrolysis reaction (HRT=10), that not only meet the requirement influent pH of anaerobic reactor, but also greatly reduce the cost of alkaline in practical application of iron carbon micro-electrolysis.