Research On The Treatment Of Viscose Wastewater By Coagulation-Hydrolytic Acidification-Activated Sludge Technology

The viscose wastewater of a chemical fiber company comes from the fiber production process, mainly including acidic wastewater and alkaline wastewater. The mixed wastewater’s SS, CODCr, BOD5value is153mg/L,328mg/L,89mg/L, respectively. Therefore, the wastewater treatment system needs high processing efficiency because of the large emissions. After the viscose wastewater treatment process of the company, the effluent wastewater can not meet the frist grade of the discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002). Therefore, the viscose wastewater treatment process needs to be improved urgently. Study on viscose wastewater treatment through laboratory testing, suggests the optimum conditions of the process by adopting coagulation-hydrolytic acidification-activated sludge.(1)Coagulation pretreatment of viscose wastewater shows that the optimum pH value is7, the optimum dosage of PAC is80mg/L, the optimum stirring time is20min.The effluent wastewater’s SS, CODCr, BOD5value is43mg/L,200mg/L,62mg/L, respectively; their removal rate can reach72%,39%,30%, respectively.(2)Hydrolytic acidification of viscose wastewater shows that the optimum HRT is5h. The effluent wastewater’s SS, CODCr, BOD5value is60mg/L,152mg/L,61mg/L, respectively. The BOD5/CODCr value of the viscose wastewater is improved to0.4, the biodegradability of wastewater is further improved to prepare for subsequent biological treatment.(3)Activated sludge process of viscose wastewater shows that the optimum aeration time is2.5h, the effluent wastewater’s SS, CODCr, BOD5value is16mg/L,32mg/L,9mg/L, respectively; their removal rate can reach73.2%,78.9%,85.2%, respectively.(4)Under the condition of optimum parameters, the effluent wastewater’s SS, CODCr, BOD5value is15mg/L,37.3mg/L,9.2mg/L, their total removal rate can reach90.2%,88.7%,89.7%with the using of coagulation-hydrolytic acidification-activated sludge combining process, respectively. The value of CODCr, BOD5can meet the frist grade of the discharge standard of pollutants for municipal wastewater treatment plant(GB18918-2002).The results show that the combined process of coagulation-hydrolytic acidification-activated sludge is feasible for the treatment of viscose wastewater. It can provide a valuable reference for the company’s application of viscose wastewater treatment.