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| Advanced treatment of the semi-coking wastewater by the combination of chemical pretreatment and biochemical treatment |
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Abstract Biodegradation of the semi-coking wastewater was improved by the combination of pretreatment technologies of the aeration ferric-carbon micro-electrolysis, the enhanced flocculation, and the catalyzed electro-oxidation through on-site pilot test. The feasibility of ensuring semi-coking wastewater to achieve wastewater discharge standards was studied through a combination of chemical pretreatment and biological treatment. The results show that COD was from 25000mg/L down to 10000mg/L, NH3-N was from 3000mg/L down to 1200mg/L, and the COD and NH3-N all reached 60% through the treatment of aeration ferric-carbon micro-electrolysis of 120 min with the adjustment pH value of about 3 of the raw water. Then, after adjustment of pH value to 8~9 for effluent of the aeration ferric-carbon micro-electrolysis, the removal rates of COD and NH3-N of the effluent of the enhanced coagulation all reached about 50% by dosing 200 mg/L of PAM and 4.5mg/L of PAM. Next, the effluent by the treatment of advanced oxidation reactor of catalyzed electro-oxidation of 120 min attained COD removal rate of up to 65% and NH3-N removal rate of 60%. Finally, the effluent by the treatment of biological contact oxidation of the anaerobic/aerobic reached COD<150mg/L and NH3-N<25mg/L. The results provide a theoretical basis for the treatment technology of the semi-coking wastewater.
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Received: 24 October 2011
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| [1] |
. [J]. CHINA ENVIRONMENTAL SCIENCECE, 2002, 22(6): 0-0. |
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