There would be strong product inhibition on ethanol fermentation process if ethanol is not removed in situ from broth. PDMS membrane pervaporation coupled with fermentation is a promising process for efficient bioetha...There would be strong product inhibition on ethanol fermentation process if ethanol is not removed in situ from broth. PDMS membrane pervaporation coupled with fermentation is a promising process for efficient bioethanol production since ethanol inhibition is relieved or eliminated. From the perspective of process operation, membrane separation performance, ethanol fermentation performance and the subsequent processing on membrane downstream are the three key issues. This review aims at contributing a comprehensive overview on the operation performance of the integrated process. The state-of-the-art of the three key issues related to the operation performance is focused. Finally, the tentative perspective on the possible future prospects of the integrated process is briefly presented.展开更多
With the rapid development of livestock and poultry breeding industries,pollution problems caused by the discharge of wastewater and manure have become increasingly severe.However,studies on the impacts of this pollut...With the rapid development of livestock and poultry breeding industries,pollution problems caused by the discharge of wastewater and manure have become increasingly severe.However,studies on the impacts of this pollution on rural residents'health are lacking.Based on data from the Peking University's China Family Panel Studies in 2010 and 2014,this paper uses a cross-sectional and panel data probit model to estimate the probability of breeding industry development in rural areas increasing the health risks of local villagers.First,the study found that the more households engaged in breeding in the region or the larger the scale of regional breeding,the higher the health risks to local villagers,particularly in areas where pigs are raised.Second,compared with individual farming,the greater the proportion of large-scale farming,the higher the health risks to villagers.Third,the development of the breeding industry seldom includes the ecological recycling of wastes and fails to reduce the use of local pesticides and fertilizers,thereby increasing the health risks to villagers.Therefore,this paper argues that providing technology to process breeding industry waste and establish an organic industrial production chain will be crucial to reducing the impact of breeding industry pollution on human health.展开更多
The recycling reverse osmosis(RO)membrane concentrate of some high-ammonia nitrogen(NH_(4)^(+)-N)organic wastewater to the biological unit could cause potassium ion(K^(+))accumulation,thereby affecting the removal of ...The recycling reverse osmosis(RO)membrane concentrate of some high-ammonia nitrogen(NH_(4)^(+)-N)organic wastewater to the biological unit could cause potassium ion(K^(+))accumulation,thereby affecting the removal of NH_(4)^(+)-N by activated sludge.Thus,the effects of high K^(+) stress on activated sludge nitrification performance was studied.The results showed that the high K^(+) stress promoted the floc sludge to produce more extracellular polymers(EPS),which accelerated the sludge sedimentation and enriched the biomass in sequential batch reactors(SBRs).The ammonia oxidation process and nitrite(NO_(2)^(-)-N)oxidation process were further analyzed in the nitrification process.High K^(+) stress enriched ammonia oxidizing bacteria(AOB),which ensured the efficient ammonia oxidation process in SBRs,and ensured the removal rate of NH_(4)^(+)-N was maintained above 93%.However,high K^(+) stress(15g/L KCl)inhibited the activity of NO_(2)^(-)-N oxidizing bacteria(NOB)and reduced the abundance of NOB,thus leading to the accumulation of NO_(2)^(-)-N,and finally worsened the nitrification performance of activated sludge.In short,the performance of activated sludge will not be inhibited when the K^(+) in the wastewater does not exceed 5.23 g/L.The results could provide a reference for the optimization of the biological performance in treating high-NH_(4)^(+)-N organic wastewater with activated sludge coupled RO membrane treatment process.展开更多
A vacuum membrane distillation(VMD)process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate.The polytetrafluoro...A vacuum membrane distillation(VMD)process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate.The polytetrafluoroethylene(PTFE)membrane flux could reach 6000 g·m-2·h-1 with the rejection efficiency of total phosphorus(TP)over 0.99,under the condition of flowrate being 120 L·h-1 and temperature being 40°C.Membrane fouling occurred with a film of organics and microorganism deposited on the surface of the membrane.Membrane flux could be reversed after the membrane was rinsed by water.Higher feed temperature and flowrate could improve the membrane flux,while hardly affect the rejection efficiency of total phosphorus.The concentration of TP could reach 1600 mg·L-1 after membrane distillation,which is about 5 times of that in initial liquid digestate.On the downstream of the membrane,some of the permeate vapor was condensed under the vacuum condition and most of water was collected here.The remaining vapor enriched with total nitrogen(TN)was compressed and pumped to the atmospheric condition to condense.The TN concentration in atmospheric condensate was as high as 7000 mg·L-1 with the process separation factor for ammonia being enhanced to 114.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20176030,20276041,20776088,21808144)China Postdoctoral Science Foundation(No.2016M592710)+1 种基金Fundamental Research Funds for the Central Universities(No.20822041B4013)Key Laboratory of Development and Application of Rural Renewable Energy,MOA,China(No.18H0491)
文摘There would be strong product inhibition on ethanol fermentation process if ethanol is not removed in situ from broth. PDMS membrane pervaporation coupled with fermentation is a promising process for efficient bioethanol production since ethanol inhibition is relieved or eliminated. From the perspective of process operation, membrane separation performance, ethanol fermentation performance and the subsequent processing on membrane downstream are the three key issues. This review aims at contributing a comprehensive overview on the operation performance of the integrated process. The state-of-the-art of the three key issues related to the operation performance is focused. Finally, the tentative perspective on the possible future prospects of the integrated process is briefly presented.
基金the financial support from the Key Laboratory of Development and Application of Rural Renewable Energy,Ministry of Agriculture and Rural Affairs,China[Grant number.2017014]National Natural Science Foundation of China(No.71973037).
文摘With the rapid development of livestock and poultry breeding industries,pollution problems caused by the discharge of wastewater and manure have become increasingly severe.However,studies on the impacts of this pollution on rural residents'health are lacking.Based on data from the Peking University's China Family Panel Studies in 2010 and 2014,this paper uses a cross-sectional and panel data probit model to estimate the probability of breeding industry development in rural areas increasing the health risks of local villagers.First,the study found that the more households engaged in breeding in the region or the larger the scale of regional breeding,the higher the health risks to local villagers,particularly in areas where pigs are raised.Second,compared with individual farming,the greater the proportion of large-scale farming,the higher the health risks to villagers.Third,the development of the breeding industry seldom includes the ecological recycling of wastes and fails to reduce the use of local pesticides and fertilizers,thereby increasing the health risks to villagers.Therefore,this paper argues that providing technology to process breeding industry waste and establish an organic industrial production chain will be crucial to reducing the impact of breeding industry pollution on human health.
基金supported by the Sichuan Science&Technology Program(No.2020YFS0438)the National Natural Science Foundation of China(No.31971386)+1 种基金the China Agriculture Research System(No.CARS-35)the Fundamental Research Funds for Central Non-profit Scientific Institution(No.2060302-022-21-016)。
文摘The recycling reverse osmosis(RO)membrane concentrate of some high-ammonia nitrogen(NH_(4)^(+)-N)organic wastewater to the biological unit could cause potassium ion(K^(+))accumulation,thereby affecting the removal of NH_(4)^(+)-N by activated sludge.Thus,the effects of high K^(+) stress on activated sludge nitrification performance was studied.The results showed that the high K^(+) stress promoted the floc sludge to produce more extracellular polymers(EPS),which accelerated the sludge sedimentation and enriched the biomass in sequential batch reactors(SBRs).The ammonia oxidation process and nitrite(NO_(2)^(-)-N)oxidation process were further analyzed in the nitrification process.High K^(+) stress enriched ammonia oxidizing bacteria(AOB),which ensured the efficient ammonia oxidation process in SBRs,and ensured the removal rate of NH_(4)^(+)-N was maintained above 93%.However,high K^(+) stress(15g/L KCl)inhibited the activity of NO_(2)^(-)-N oxidizing bacteria(NOB)and reduced the abundance of NOB,thus leading to the accumulation of NO_(2)^(-)-N,and finally worsened the nitrification performance of activated sludge.In short,the performance of activated sludge will not be inhibited when the K^(+) in the wastewater does not exceed 5.23 g/L.The results could provide a reference for the optimization of the biological performance in treating high-NH_(4)^(+)-N organic wastewater with activated sludge coupled RO membrane treatment process.
基金supported by the Fundamental Research Funds for the Central Universities(No.20822041B4013)Key Laboratory of Development and Application of Rural Renewable Energy,Ministry of Agriculture and Rural Affairs,China(No.18H0491)。
文摘A vacuum membrane distillation(VMD)process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate.The polytetrafluoroethylene(PTFE)membrane flux could reach 6000 g·m-2·h-1 with the rejection efficiency of total phosphorus(TP)over 0.99,under the condition of flowrate being 120 L·h-1 and temperature being 40°C.Membrane fouling occurred with a film of organics and microorganism deposited on the surface of the membrane.Membrane flux could be reversed after the membrane was rinsed by water.Higher feed temperature and flowrate could improve the membrane flux,while hardly affect the rejection efficiency of total phosphorus.The concentration of TP could reach 1600 mg·L-1 after membrane distillation,which is about 5 times of that in initial liquid digestate.On the downstream of the membrane,some of the permeate vapor was condensed under the vacuum condition and most of water was collected here.The remaining vapor enriched with total nitrogen(TN)was compressed and pumped to the atmospheric condition to condense.The TN concentration in atmospheric condensate was as high as 7000 mg·L-1 with the process separation factor for ammonia being enhanced to 114.
