Investigation For Technology Of Dealing With Wastewater From Dyeing And Finishing For Linen Fiber

The process of coagulative precipitation, activated carbon static adsorption and sodiumhypochlorite oxidation method dealing with linen fiber dyeing and finishing wastewater wasstudied through the analysis of linen fiber dyeing and finishing process and its wastewaterquality characteristics.Linen fiber dyeing and finishing wastewater was pretreated by coagulative precipitation,and suitable coagulant was chosen by preliminary screening.The influence of pH and dosageon coagulation were investigated by the single factor experiment, and the optimum coagulantwere chosen. The influence of each factor on the coagulation effect was analysed, and itsoptimum treatment process was determined by the orthogonal experiment. The results showthat aluminum sulfate (AS) was the optimum coagulant. The optimum process of coagulationprecipitation to treat the wastewater was as follows. Aluminum sulfate dosage was3.6g/L,The pH of the wastewater was8, coagulant aid polyacrylamide （PAM） was0.01g/L. Underthe optimal process, colority removal rate was86.40%, turbidity removal rate was85.75%,the COD removal rate was56.04%, the suspended solids removal rate was64.71%.The linen fiber dyeing and finishing wastewater which after coagulation precipitationoptimum process primary treatment was treated by powdery activated carbon through theactivated carbon static adsorption experiments, and the influence of pH and dosage onwastewater treatment effect were investigated by single factor experiment. The optimumprocess of activated carbon static adsorption experiment was as follows. Activated carbondosage was0.7g/L, The pH of the wastewater was5. Under the optimal process, colorityremoval rate was88.24%, turbidity removal rate was77.12%, COD removal rate was69.03%,suspended solids removal rate was66.67%.The wastewater which treated after the coagulative precipitation-activated carbon staticadsorption optimum process was treated by sodium hypochlorite oxidation method. Theinfluence of dosage reacting time and pH on wastewater treatment process were furtherdiscussed by orthogonal and single factor experiment of sodium hypochlorite oxidation,andthen the optimum treatment process were chosen. The results show that the optimum processof sodium hypochlorite oxidation experiment was as follows. The sodium hypochloritedosage was3.5ml/L, The pH of the wastewater was9, the reacting time was50min.Under the optimal process, colority removal rate is as high as90.00%, turbidity removal rate was79.00%, COD removal rate was71.00%, suspended solids removal rate was51.61%.The experimental results show that coagulative precipitation-activated carbonadsorption-sodium hypochlorite oxidation process which used in dealing with linen fiberdyeing and finishing wastewater has certain feasibility. The Research of combination processand the analysis of wastewater chromatographic results both show that linen fiber dyeing andfinishing wastewater can reach textile printing and dyeing wastewater primary dischargestandard through the method.