Removal of organic pollutants from 2,2',5,5'-tetrachlorobenzidine (TCB) industrial wastewater by micro-electrochemical oxidation and air-stripping.
A feasible method for treatment of the wastewater from the two-staged neutralization in 2,2',5,5'-tetrachlorobenzidine (TCB) manufacturing processes, a refractory dye intermediate effluents, based on combined micro-electrochemical oxidation or iron-chipping filtration (ICF) and air-stripping reactor (ASR), was developed. On conditions of HRT 1h, pH 3.0 in ICF and HRT 38 h, gas-liquid ratio 15, pH 6.0-8.65, temperature 26 degrees C in ASR, the overall COD, color, TCB and NH(4)(+)-N removal were 96.8%, 91%, 87.61% and 62%, respectively, during the treatment of TCB wastewater from the two-staged neutralization dissolved by methanol. The averaged 18.3%, 81.7% of the total degraded COD, 35.2%, 64.8% of TCB were carried out in ICF and ASR, respectively. NH(4)(+)-N removal was finished mainly in ASR. The experimental results indicated that the combined micro-electrochemical oxidation and air-stripping process performed good treatment of COD, color, TCB and NH(4)(+)-N removal in TCB wastewater from the two-staged neutralization dissolved by ethanol or acetone, came up the discharge standard in China. But the TCB wastewater from the two-staged neutralization dissolved by methanol should be deeply treated before discharged.
Shibin
Xia
X
Department of Environmental Science and Technology, School of Resource and Environment, Wuhan University of Technology, PO Box 122, Wuhan, Hubei Province, PR China. xiashibin@126.com
Shuichun
Xia
X
Changqing
Zhu
Z
D001560:Benzidines / Q000737:chemistry*; D003116:Color; D004563:Electrochemistry; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D001560:Benzidines; D007220:Industrial Waste; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; D007501:Iron; C034088:2,2',5,5'-tetrachlorobenzidine