Study On Process Technology Of Heavy Nitrogen Wastewater Treatment By Biochemical Process

With the rapid development of industrial production, pollution of high density chemical wastewater is increasingly serious. Due to different properties and sources, the high density chemical wastewater is difficult and costly to be brought under control, and the treatment of it has become an urgent issue of the global environmental protection technology.The paper mainly evaluates the B/C biodegradability of diazonium wastewater discharged by a certain chemical factory. Besides, through mixing the diazonium wastewater with other production wastewater and using micro-electrolysis to elevate the its biodegradability, the paper evaluates the contribution value of such methods to improve the B/C ratio of diazonium wastewater. Experiments are performed for the diazonium wastewater through cultivation of suitable microorganisms and simulation of biochemical reaction, in a bid to analyze the feasibility of biological treatment method for diazonium wastewater. And the capability of the chemical factory in biological treatment of diazonium wastewater is assessed.After lab tests and field experiments, it is found that diazonium wastewater is not biodegradable. However, its biodegradability is effectively improved through matching, mixing and homogenizing with normal production wastewater. When the diazonium wastewater is mixed with production wastewater at 4:300, the B/C ratio rises from 0.22 to 0.30, which is the critical value for biodegradability treatment. Micro-electrolysis action is also effective for improving the biodegradability of diazonium wastewater. When the diazonium wastewater is mixed with production water at 8:300, the B/C ratio of the mixed wastewater is elevated to the level of biodegradability.The experiments draw the conclusion that mixture and micro-electrolysis can improve the biodegradability of the diazonium wastewater. Moreover, through cultivation of suitable microorganisms, it is feasible to treat diazonium wastewater biologically. The field application proves that the chemical factory is capable of treating 5m3 diazonium wastewater every day by the biological treatment method with the help of its wastewater treatment facility. After the treatment, the effluent COD reduces to 96mg/L, NH3-N to 22 mg/L and Cl- to 386mg/L. All the indexes meet the Class III of Table 4 in the Integrated Wastewater Discharge Standard (GB8978-1996), and the acceptable standard signed with the wastewater treatment plant in the local economic and technological development zone. Therefore, it is feasible to improve the biodegradability of diazonium wastewater through mixing it with production wastewater and micro-electrolysis, and the diazonium wastewater can be treated biologically.