A bioreactor system with a total working volume of 4 8 L,composed of four airlift suspended bed bioreactors, one of which was designated for seed cultivation and the others in series for ethanol fermentation, was esta...A bioreactor system with a total working volume of 4 8 L,composed of four airlift suspended bed bioreactors, one of which was designated for seed cultivation and the others in series for ethanol fermentation, was established and continuously operated for 40 days A self flocculating fusant from Saccharomyces cerevisiae and Schizosaccharomyces pombe (SPSC 01) was used and ethanol and yeast were co produced from corn dry milling, two stage enzymatic hydrolysis (raw material residues were separated after saccharification).The results showed that average levels of 98 g·L -1 for ethanol, 4 g·L -1 for residual reduced sugar and 6—9 g·L -1 for residual total sugar were achieved when the medium containing total sugar of 220 g·L -1 was fed at a dilution rate of 0 05 h -1 .Pure yeast, equivalent to 5% (mass) of ethanol and containing protein as high as 48 6%(mass), was co produced Ethanol production is expected to be more economically competitive as this high quality yeast potentially can be further processed as value added by products.展开更多
Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigate...Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.展开更多
Lysozyme reaction was developed as a novel technique for minimizing the amount of excess sludge in the sequential batch reactor(SBR).In the present work,excess sludge taken from a SBR system was treated by lysozyme re...Lysozyme reaction was developed as a novel technique for minimizing the amount of excess sludge in the sequential batch reactor(SBR).In the present work,excess sludge taken from a SBR system was treated by lysozyme reaction and then returned to the reactor.The quality of the effluent water and characteristics of the activated sludge in the SBR were analyzed to determine the effectiveness of the reduction process.The results show that excess sludge production could be reduced to almost 100%in the first30 d of operation and could be reduced to further by 40%in the succeeding 20 d or so.In these time periods,the average removal efficiencies of the chemical oxygen demand and total nitrogen are 87.38%and 52.78%,respectively,whereas the average total phosphorous in the effluent is nearly 17.18%greater than that of the effluent of the reference system.After 50 d of operation,the sludge floc size is in the range of 20 to 80μm,which was smaller than the size prior to the start of the hydrolysis and the ratio of mixed liquor volatile suspended solids/mixed liquor suspended solids increases from 86%to 90%.展开更多
文摘A bioreactor system with a total working volume of 4 8 L,composed of four airlift suspended bed bioreactors, one of which was designated for seed cultivation and the others in series for ethanol fermentation, was established and continuously operated for 40 days A self flocculating fusant from Saccharomyces cerevisiae and Schizosaccharomyces pombe (SPSC 01) was used and ethanol and yeast were co produced from corn dry milling, two stage enzymatic hydrolysis (raw material residues were separated after saccharification).The results showed that average levels of 98 g·L -1 for ethanol, 4 g·L -1 for residual reduced sugar and 6—9 g·L -1 for residual total sugar were achieved when the medium containing total sugar of 220 g·L -1 was fed at a dilution rate of 0 05 h -1 .Pure yeast, equivalent to 5% (mass) of ethanol and containing protein as high as 48 6%(mass), was co produced Ethanol production is expected to be more economically competitive as this high quality yeast potentially can be further processed as value added by products.
基金Projects(51874071,52022019,51734005)supported by the National Natural Science Foundation of ChinaProject(161045)supported by the Fok Ying Tung Education Foundation for Yong Teachers in the Higher Education Institutions of China。
文摘Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.
基金Project(51078130)supported by the National Natural Science Foundation of ChinaProject(10C0419)supported by the the Education Department of Hunan Province,China
文摘Lysozyme reaction was developed as a novel technique for minimizing the amount of excess sludge in the sequential batch reactor(SBR).In the present work,excess sludge taken from a SBR system was treated by lysozyme reaction and then returned to the reactor.The quality of the effluent water and characteristics of the activated sludge in the SBR were analyzed to determine the effectiveness of the reduction process.The results show that excess sludge production could be reduced to almost 100%in the first30 d of operation and could be reduced to further by 40%in the succeeding 20 d or so.In these time periods,the average removal efficiencies of the chemical oxygen demand and total nitrogen are 87.38%and 52.78%,respectively,whereas the average total phosphorous in the effluent is nearly 17.18%greater than that of the effluent of the reference system.After 50 d of operation,the sludge floc size is in the range of 20 to 80μm,which was smaller than the size prior to the start of the hydrolysis and the ratio of mixed liquor volatile suspended solids/mixed liquor suspended solids increases from 86%to 90%.
