The Degradation Of Papermaking Middle-stage Effluent With Mixed Flora And The Effects On The Following Advanced Treatment

The pulp water of papermaking pulp is the waste water which is discharged during washing,bleaching and filtering after washing,bleaching and filtering,the emissions are relatively large,The dissolved lignin and its derivatives make the wastewater a series of color from light brown to dark brown,Untreated emissions will cause pollution and damage to the environment.The microbial strains were screened and cultured,and the biodegradation of most organic compounds was processed.The bacteria were extracted from the pulp of papermaking process by dilution multiple method and diluted dilution method.The removal effect of COD in the middle section of papermaking was tested,and the growth curve of the paper was described by spectrophotometry.The highly effective strains selected by these two methods are W2、H4、H6、S4、S3、H3.All of the removal rates of W2、H4、H6 and S4 were reached to 60%,and the removal rates of H3 and S3 were also over 30%.Six different strains(W2、H4、H6、S4、S3、H3)screened were used to construct a bacterial consortium for COD degradation of pulping effluents with the experimental designs statistically.The research results showed that the strains of H3、H4 and S3 had positive effects for the removal of COD,and the interaction effects of X1X4 and X1X2X6 were also positive.However,the interaction effect of X1X2 was negative(where,X1 is W2,X2 is H4,X4 is S4,X6 is H3).A frist order prediction model was established by using multiple regression analysis,and five strains of W2、H4、S4、S3 and H3 were selected to construct bacterial consortium finally.The process of treatment of pulping effluent with Fenton method was optimized,and the optimal process is: pH 5.5,16 m L 10% Fe2SO4 solution in 400 mL pulping effluent,0.6 mL 30% H2O2 solution in 400 mL pulping effluent.COD removal rate of pulpint effluent was 91.3% under the conditions of optimal process.Synergistic effect of biological treatment and Fenton method was more predominant than that of Fenton method separately.The combined effect of biological treatment and Fenton method can remove more COD from pulping effluent with a lower cost.