Study And Application On Pretreatment Of Molasses Fermentation Wastewater By VTBR Anaerobic Reactor

The molasses fermentation wastewater,which has high concentration of organic pollutants and complex composition,is produced during the production of molasses yeast.Being a typical high concentration organic wastewater,it is difficult for enterprises to deal with.There have been many studies on the treatment of molasses fermentation wastewater at home and abroad,and the best method at present is anaerobic digestion.Based on feasibility,applicability and economy,this paper is try to design the pretreatment experiments,verify the efficiency of coagulation and VTBR anaerobic digestion,and devotes to finding out the best operating conditions of the experiments,by investigating the characteristics of molasses fermentation wastewater.According to the experimental results,the anaerobic pretreatment scheme and process of molasses fermentation wastewater were designed.Through the field commissioning and operation of the project,the experiences of pretreatment of molasses fermentation wastewater by VTBR anaerobic reactor were summarized,which provided theoretical and practical basis for the pretreatment of similar wastewater projects.The experiments proved that after the molasses fermentation wastewater has been coagulated,the volumetric load of the VTBR anaerobic reactor can reach 2.0 kg COD/(m3·d)under the condition that the molasses fermentation wastewater is not desalted and undiluted,the COD removal rate is above 75%,and the ratio of COD removal to biogas production is about 0.35 L/g.The experiments showed that the domestication time of anaerobic sludge of VTBR anaerobic reactor need about 35 days,the reaction temperature shall be controlled at about 35℃,pH 7.5~9.5,and the hydraulic residence time 6 days.Engineering applications proved that the COD removal rate of molasses fermentation wastewater coagulation treatment is about 10 %,the effluent COD concentration of the VTBR reactor is less than 4,000 mg/L,the anaerobic pretreatment cost of molasses fermentation wastewater is 3.45 yuan/t,the biogas produced by VTBR anaerobic reactor can be fully recovered and recycled.Therefore,the pretreatment of molasses fermentation wastewater by VTBR anaerobic reactor is effective and practical,the whole system is stable in engineering application,the removal rate of COD can reach about 75 %,and the utilization of biogas can be realized.The pretreatment of molasses fermentation wastewater by VTBR anaerobic reactor has great Extension and application values.