Effects Of Surfactants And Activated Carbon On Anaerobic Fermentation Of Molasses Alcohol Wastewater

Molasses alcohol wastewater is a kind of waste liquid discharged from the crude distillation tower in the process of alcohol production with molasses.It has the characteristics of low pH,high levels of pigment,and high content of organic matter,large emissions and difficult treatment.In addition,molasses wastewater has the characteristics of high viscosity,which is different from other wastewater.Anaerobic digestion(AD)technology can implement the requirements of renewable energy production and waste treatment at the same time,so it is widely used in wastewater treatment.Additives play an important role in anaerobic fermentation of wastewater,but there are few studies on reducing sludge viscosity with additives.This study takes advantage of surfactants which can reduce the surface activity and increase the solubility of organic matter and activated carbon which has the characteristics of adsorption and conductivity.In the process of molasses alcohol wastewater treatment,surfactants,Activated Carbon and Activated Carbon combined with ceramic chips were added to study their effects on wastewater treatment,in order to reduce the sludge viscosity,prolong the sludge use time and optimize the treatment process.In this paper,different concentrations of APG,RL and SDS surfactants,as well as different concentrations of Activated Carbon and the combination of Activated Carbon and ceramic chips were added respectively.The effects on wastewater treatment were observed by detecting the removal rate of chemical oxygen demand(COD),ammonia nitrogen content,volatile fatty acids(VFA),decolorization rate,methane content and other indicators.The changes of microbial composition and structure of sludge were analyzed by microbial community analysis and electron microscope observation of different groups.The results were obtained from two aspects of organic matter removal efficiency and sludge structure change.The main results are as follows:(1)The addition of surfactant SDS had a negative effect on the COD removal rate.Both APG and RL could reduce sludge viscosity,5 m Pa·s and 15.5 m Pa·s at most respectively.The optimal dosage of APG was 100 mg/L,which could increase the removal rate of COD and BOD by 4.93% and 6.83%respectively.It could also reduce the content of ammonia nitrogen,improve the decolorization rate and alkalinity.16 S rRNA high-throughput sequencing results showed that the APG group had the highest microbial richness and diversity,and increased the number of Family??,Anaerolineaceae,Desulfovibrionaceae and Methanosaetaceae.Adding 50 and 100 mg/L RL had positive effects on COD removal rate,decolorization rate and methane content,but 100 mg/L RL reduced TS and viscosity more.Under this condition,the abundance and diversity of Archaea in the RL group were higher than those in the CK group,Family???Anaerolineaceae ? Dysgonomonadaceae ? Family?? increased,and Methanosarcinaceae increased significantly.(2)The viscosity of sludge added with Activated Carbon or ceramic chips was lower than that of CK,which decreased by 19.7 m Pa·s and 20 m Pa·s at most respectively.When the dosage of Activated Carbon was 10 g/L,the removal rate of COD increased by 4.28%,the content of methane was the highest,and the content of sulfate decreased by 40 mg/L,which also had a positive effect on decolorization.In the ceramic group,when adding ceramic chips alone,the removal rate of COD was the highest,the first hydraulic retention time(HRT)increased by 3.10%,the ammonia nitrogen was the lowest,and it decreased by 92.11 mg/L at the end of the reaction,and the methane content was the highest.At the optimum dosage,the addition of Activated Carbon and ceramic chips could increase the abundance of archaea,and enrich Christensenellaceae,Synergistaceae,Bacteroidetes?Vadin ha17 and other hydrolytic bacteria.Different additives had different effects on treatment efficiency.In general,adding 100 mg/L APG,100 mg/L RL,10 g/L Activated Carbon and ceramic chips alone had better effects.The results deepened the understanding of the effects of different kinds and concentrations of surfactants and Activated Carbon on the anaerobic fermentation of molasses alcohol wastewater,provided a reference for the selection of wastewater treatment additives,and had important significance for reducing sludge viscosity and optimizing treatment process of wastewater.