By combining sequencing batch reactor (SBR) activated sludge process and constructed wetland (CW), this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating paramet...By combining sequencing batch reactor (SBR) activated sludge process and constructed wetland (CW), this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating parameters of the combined process. The process involved advantages and shortages of SBR and CW. Under normal temperature, the 3rd cycle (SBR’s operation cycle is 8 h: inflow for 1 h, limited aeration for 3 h, sediment for 1 h, outflow for 1 h, and idling for 2 h; CW’s hydraulic retention time (HRT) is 24.8 h and hydraulic loading is 24.5 m3/m2 d) was the best cyclic mode. The effluents can meet the standard GB/T18921-2002: "The reuse of urban recycling water: water quality standard for scenic environment use". In the 3rd cycle, the efficiency of CW was the maximum, and energy consumption of SBR was the minimum. Under the condition of low dissolved oxygen, the removing efficiency of chemical oxygen demand (COD) and ammonia was not affected obviously. Simultaneously, nitrification and denitrification phenomena occured and phosphorus was absorbed obviously.展开更多
In order to improve poly-β-hydroxybutyrate（PHB） production in activated sludge, the anaerobic/aerobic alternative operating sequencing batch reactor（SBR） process was applied in this paper to accumulate PHB. Effec...In order to improve poly-β-hydroxybutyrate（PHB） production in activated sludge, the anaerobic/aerobic alternative operating sequencing batch reactor（SBR） process was applied in this paper to accumulate PHB. Effects of nutritional conditions and carbon concentration on PHB accumulation were studied. Results indicated that PHB accumulation reached the highest level and accounted for 11.2 % under anaerobic condition for phosphate limitation and 20.84 % under aerobic condition for nitrogen and phosphate limitation of mixed liquor suspended solid（MLSS）, respectively. In addition, 4 g/L was proved to be the optimum carbon concentration in both anaerobic and aerobic experiments, and the PHB accumulation reached 17.1 %（anaerobic, phosphorus limitation） and 60.4 %（aerobic, nitrogen and phosphorus limitation） of MLSS, respectively. PHB could be successfully extracted with sodium hypochlorite and chloroform method from the activated sludge. In addition, the infrared spectrum showed that the PHB sample extracted was of high purity.展开更多
The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammoni...The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammonium oxidation.The enrichment of anammox bacteria was carried out in a 7.0-L sequencing batch reactor(SBR)and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR.Research results,especially the biomass,showed first signs of anammox activity after 54 d cultivation with synthetic wast...展开更多
The effect of high-strength ammonia nitrogen acclimation on sludge activity in sequencing batch reactor （SBR） was investigated. Two batch experiments, RUN1 and RUN2, were conducted with the influent ammonia nitrogen...The effect of high-strength ammonia nitrogen acclimation on sludge activity in sequencing batch reactor （SBR） was investigated. Two batch experiments, RUN1 and RUN2, were conducted with the influent ammonia nitrogen concentrations 60 and 500 mg/L, respectively. The sludges inoculated from RUN1 and RUN2 were used to treat a series of influent with ammonia nitrogen concentrations of 59, 232, 368, 604 and 1152 mg/L. It is found that the activated sludge acclimated to higher ammonia nitrogen concentrations revealed higher COD and NH 4 ＋ -N removal efficiencies, and slower DHA decrease. The results confirmed that the activities of the bacteria in activated sludge in SBR were inhibited by high-strength ammonia nitrogen, whereas the activated sludge acclimated to high-strength ammonia nitrogen showed substantial resistance to inhibition by influents containing high levels of ammonia nitrogen.展开更多
In order to improve the nitrogen removal efficiency and save operational cost,the feasibility of the alternating aerobic-anoxic process(AAA process)applied in a sequencing batch reactor(SBR)system for nitrogen removal...In order to improve the nitrogen removal efficiency and save operational cost,the feasibility of the alternating aerobic-anoxic process(AAA process)applied in a sequencing batch reactor(SBR)system for nitrogen removal was investigated.Under sufficient influent alkalinity,the AAA process did not have an advantage over one aerobic-anoxic(OAA)cycle on treatment efficiency because microorganisms had an adaptive stage at the alternating aerobic-anoxic transition,which would prolong the total cycling time.On the contrary,the AAA process made the system control more complicated.Under deficient influent alkalinity,when compared to OAA,the AAA process improved treatment efficiency and effluent quality with NH4+-N in the effluent below the detection limit.In the nitrification,the average stoichiometric ratio between alka-linity consumption and ammonia oxidation is calculated to be 7.07 mg CaCO_(3)/mg NH4+-N.In the denitrification,the aver-age stoichiometric ratio between alkalinity production and N_(3)^(−)-N reduction is about 3.57 mg CaCO(3)/mg NO_(3)^(−)-N.As a result,half of the alkalinity previously consumed during the aerobic nitrification was recovered during the subsequent anoxic denitrification period.That was why the higher treat-ment efficiency in the AAA process was achieved without the supplement of bicarbonate alkalinity.If the lack of alkalinity in the influent was less than 1/3 of that needed,there is no need for external alkalinity addition and treatment efficiency was the same as that under sufficient influent alkalinity.Even if the lack of alkalinity in the influent was more than 1/3 of that needed,the AAA process was an optimal strategy because it reduced the external alkalinity addition and saved on operational cost.展开更多
基金Funded by Sustainable Water Management Improves Tomorrow’s City’s Health (SWITCH018530)
文摘By combining sequencing batch reactor (SBR) activated sludge process and constructed wetland (CW), this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating parameters of the combined process. The process involved advantages and shortages of SBR and CW. Under normal temperature, the 3rd cycle (SBR’s operation cycle is 8 h: inflow for 1 h, limited aeration for 3 h, sediment for 1 h, outflow for 1 h, and idling for 2 h; CW’s hydraulic retention time (HRT) is 24.8 h and hydraulic loading is 24.5 m3/m2 d) was the best cyclic mode. The effluents can meet the standard GB/T18921-2002: "The reuse of urban recycling water: water quality standard for scenic environment use". In the 3rd cycle, the efficiency of CW was the maximum, and energy consumption of SBR was the minimum. Under the condition of low dissolved oxygen, the removing efficiency of chemical oxygen demand (COD) and ammonia was not affected obviously. Simultaneously, nitrification and denitrification phenomena occured and phosphorus was absorbed obviously.
基金Funded by the Fundamental Research Funds for the Central Universities(No.2572014CA23)the National Natural Science Foundation of China(No.51678120)
文摘In order to improve poly-β-hydroxybutyrate（PHB） production in activated sludge, the anaerobic/aerobic alternative operating sequencing batch reactor（SBR） process was applied in this paper to accumulate PHB. Effects of nutritional conditions and carbon concentration on PHB accumulation were studied. Results indicated that PHB accumulation reached the highest level and accounted for 11.2 % under anaerobic condition for phosphate limitation and 20.84 % under aerobic condition for nitrogen and phosphate limitation of mixed liquor suspended solid（MLSS）, respectively. In addition, 4 g/L was proved to be the optimum carbon concentration in both anaerobic and aerobic experiments, and the PHB accumulation reached 17.1 %（anaerobic, phosphorus limitation） and 60.4 %（aerobic, nitrogen and phosphorus limitation） of MLSS, respectively. PHB could be successfully extracted with sodium hypochlorite and chloroform method from the activated sludge. In addition, the infrared spectrum showed that the PHB sample extracted was of high purity.
文摘The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammonium oxidation.The enrichment of anammox bacteria was carried out in a 7.0-L sequencing batch reactor(SBR)and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR.Research results,especially the biomass,showed first signs of anammox activity after 54 d cultivation with synthetic wast...
基金supported by the Foundation of the Ministry of Education(No.WTWER0702)
文摘The effect of high-strength ammonia nitrogen acclimation on sludge activity in sequencing batch reactor （SBR） was investigated. Two batch experiments, RUN1 and RUN2, were conducted with the influent ammonia nitrogen concentrations 60 and 500 mg/L, respectively. The sludges inoculated from RUN1 and RUN2 were used to treat a series of influent with ammonia nitrogen concentrations of 59, 232, 368, 604 and 1152 mg/L. It is found that the activated sludge acclimated to higher ammonia nitrogen concentrations revealed higher COD and NH 4 ＋ -N removal efficiencies, and slower DHA decrease. The results confirmed that the activities of the bacteria in activated sludge in SBR were inhibited by high-strength ammonia nitrogen, whereas the activated sludge acclimated to high-strength ammonia nitrogen showed substantial resistance to inhibition by influents containing high levels of ammonia nitrogen.
基金This work was supported by the National Nature Science Foundation of China(Grant No.50608001)Beijing Education Committee(Grant No.KM200710005014).
文摘In order to improve the nitrogen removal efficiency and save operational cost,the feasibility of the alternating aerobic-anoxic process(AAA process)applied in a sequencing batch reactor(SBR)system for nitrogen removal was investigated.Under sufficient influent alkalinity,the AAA process did not have an advantage over one aerobic-anoxic(OAA)cycle on treatment efficiency because microorganisms had an adaptive stage at the alternating aerobic-anoxic transition,which would prolong the total cycling time.On the contrary,the AAA process made the system control more complicated.Under deficient influent alkalinity,when compared to OAA,the AAA process improved treatment efficiency and effluent quality with NH4+-N in the effluent below the detection limit.In the nitrification,the average stoichiometric ratio between alka-linity consumption and ammonia oxidation is calculated to be 7.07 mg CaCO_(3)/mg NH4+-N.In the denitrification,the aver-age stoichiometric ratio between alkalinity production and N_(3)^(−)-N reduction is about 3.57 mg CaCO(3)/mg NO_(3)^(−)-N.As a result,half of the alkalinity previously consumed during the aerobic nitrification was recovered during the subsequent anoxic denitrification period.That was why the higher treat-ment efficiency in the AAA process was achieved without the supplement of bicarbonate alkalinity.If the lack of alkalinity in the influent was less than 1/3 of that needed,there is no need for external alkalinity addition and treatment efficiency was the same as that under sufficient influent alkalinity.Even if the lack of alkalinity in the influent was more than 1/3 of that needed,the AAA process was an optimal strategy because it reduced the external alkalinity addition and saved on operational cost.
