Study On Pretreatment For Chemical Industry Wastewater And New Type Of Inner-electrolysis Reactor

This work basing on experiments regards the pretreatment for a kind of chemical industry wastewater. A study of pretreatment of chemical industry wastewater with high concentration contamination by non-aerate inner-electrolysis was carried out. The optimum operation conditions are as follows: pH is 4-5, the rate of the solid quality and the liquid bulk is 0.8 g/ml, HRT is 60 minutes, the reactive temperature is room temperature, the ratio of the iron and the active carbon quality is 3:1, the removal rates of COD and chromaticity were 71.6 % and 87.5 % respectively, the BOD₅/COD ratio was improved from 0.09 to 0.19, and the method reached a good pretreatment effect.Second, to overcome the drawbacks of the inner-electrolysis reactors a new type reactor with simple construction and operation convenience was designed. Its appliance results was studied by two kinds of chemical industry wastewater on non-aerate inner-electrolysis condition. The results indicate that the removal rates of COD and chromaticity was good pretreatment effect and its appliance foreground was well. The iron was loaded expediently, contemporary. The iron was not agglomeration on the condition that the iron was blow the level of wastewater.Finally, the photo oxidative degradation of chemical industry wastewater with high concentration contamination by solar/H₂O₂/ferric oxalate and inner-electrolysis method has been studied. The results indicate that under the initial conditions of 15 min of irradiation under sunny sky, pH 4.0, C₂O₄^2- 0.8 mmol/L, Fe²⁺ 0.8 mmol/L, and H₂O₂ 25 ml/L, the removal of chromaticity and COD can reach at 87.3% and 93.8% completely. And the organic contamination in the wastewater can be rapidly degraded by the process. The removal rates of chromaticity and COD were 99.3% and 96.9 % respectively and the B/C ratio can reach over 0.3 by inner-electrolysis method and solar/H₂O₂/ferric oxalate method.