The combined submerged biofilm （SBF）-activated sludge （AS） process for treatment of municipal wastewater in a small city in China is described in this paper. The process exhibited high removal efficiencies for car...The combined submerged biofilm （SBF）-activated sludge （AS） process for treatment of municipal wastewater in a small city in China is described in this paper. The process exhibited high removal efficiencies for carbonaceous substances, nitrogen and phosphorus which mainly took place in the combined SBF-AS bioreactor. The SBF-AS bioreactor was divided into pre-anoxic, anaerobic, anoxic and aerobic zones from inlet to outlet, in which fixed biofilm carriers were packed. Excellent performance had been obtained under normal operating conditions in more than one year of operation in Dong’e municipal WWTP, Shandong province, with mean removal efficiencies of BOD5 934%, COD 88%, SS 92%, NH+4-N 821%, TP 75% and TN 667%, and quite high effluent quality such as BOD5 6 to 10 mg/L, COD 20 to 40 mg/L, SS 5 to 10 mg/L, TN 10 to 20 mg/L, NH+4-N 4 to 8 mg/L and TP 06 to 10 mg/L. The effluent was reused multi-purposely, such as toilet flushing, green belt watering and artificial lake pounding. Simultaneous nitrification and denitrification took place due to the DO gradient in biofilm in aerobic zone of the SBF-AS bioreactor, which made TN removal efficiency improved remarkably in system. Some activated sludge was returned from final clarifiers to the bioreactor for phosphorus removal. The process had the advantages of low investment and low operational/maintenance （O/M） costs, low sludge yield and was preferably employed in small towns and cities.展开更多
Small RNAs(sRNAs)are key players in the regulation of bacterial gene expression.However,the distribution and regulatory functions of sRNA in pig farm wastewater treatment plants(WWTPs)remains unknown.In this study,the...Small RNAs(sRNAs)are key players in the regulation of bacterial gene expression.However,the distribution and regulatory functions of sRNA in pig farm wastewater treatment plants(WWTPs)remains unknown.In this study,the wastewaters in anoxic and oxic tanks of the WWTPs were collected.The profiles of the community structure,mRNA expression,and sRNA expression of bacteria in pig farm wastewater were investigated using transcriptome sequencing and qPCR.This study demonstrated that there was a higher abundance of sRNA in the pig farm WWTPs and 52 sRNAs were detected.The sRNAs were mainly present in Proteobacteria and Firmicutes,including the potential human pathogenic bacteria(HPB)(Escherichia,Shigella,Bordetella and Morganella),crop pathogen(Pectobacterium)and denitrifying bacteria(Zobellella).And the sRNAs were involved in the bacterial functional activities such as translation,transcription,drug resistance,membrane transport and amino acid metabolism.In addition,most sRNAs had a higher abundance in anoxic tanks which contained a higher abundance of the genes associated with infectious diseases and drug resistance than that in oxic tanks.The results presented here show that in pig farm WWTPs,sRNA played an important role in bacterial function activities,especially the infectious diseases,drug resistance and denitrification,which can provide a new point of penetration for improving the pig farm WWTPs.展开更多
文摘The combined submerged biofilm （SBF）-activated sludge （AS） process for treatment of municipal wastewater in a small city in China is described in this paper. The process exhibited high removal efficiencies for carbonaceous substances, nitrogen and phosphorus which mainly took place in the combined SBF-AS bioreactor. The SBF-AS bioreactor was divided into pre-anoxic, anaerobic, anoxic and aerobic zones from inlet to outlet, in which fixed biofilm carriers were packed. Excellent performance had been obtained under normal operating conditions in more than one year of operation in Dong’e municipal WWTP, Shandong province, with mean removal efficiencies of BOD5 934%, COD 88%, SS 92%, NH+4-N 821%, TP 75% and TN 667%, and quite high effluent quality such as BOD5 6 to 10 mg/L, COD 20 to 40 mg/L, SS 5 to 10 mg/L, TN 10 to 20 mg/L, NH+4-N 4 to 8 mg/L and TP 06 to 10 mg/L. The effluent was reused multi-purposely, such as toilet flushing, green belt watering and artificial lake pounding. Simultaneous nitrification and denitrification took place due to the DO gradient in biofilm in aerobic zone of the SBF-AS bioreactor, which made TN removal efficiency improved remarkably in system. Some activated sludge was returned from final clarifiers to the bioreactor for phosphorus removal. The process had the advantages of low investment and low operational/maintenance （O/M） costs, low sludge yield and was preferably employed in small towns and cities.
基金financially supported by the Guangdong Technological Innovation Strategy of Special Funds(Key Areas of Research and Development Program,No.2018B020205003)
文摘Small RNAs(sRNAs)are key players in the regulation of bacterial gene expression.However,the distribution and regulatory functions of sRNA in pig farm wastewater treatment plants(WWTPs)remains unknown.In this study,the wastewaters in anoxic and oxic tanks of the WWTPs were collected.The profiles of the community structure,mRNA expression,and sRNA expression of bacteria in pig farm wastewater were investigated using transcriptome sequencing and qPCR.This study demonstrated that there was a higher abundance of sRNA in the pig farm WWTPs and 52 sRNAs were detected.The sRNAs were mainly present in Proteobacteria and Firmicutes,including the potential human pathogenic bacteria(HPB)(Escherichia,Shigella,Bordetella and Morganella),crop pathogen(Pectobacterium)and denitrifying bacteria(Zobellella).And the sRNAs were involved in the bacterial functional activities such as translation,transcription,drug resistance,membrane transport and amino acid metabolism.In addition,most sRNAs had a higher abundance in anoxic tanks which contained a higher abundance of the genes associated with infectious diseases and drug resistance than that in oxic tanks.The results presented here show that in pig farm WWTPs,sRNA played an important role in bacterial function activities,especially the infectious diseases,drug resistance and denitrification,which can provide a new point of penetration for improving the pig farm WWTPs.
