[Objective] The study was conducted to optimize the operation parameters of water control equipment for deep-litter beddings. [Method] A four-factor three-level orthogonal design was adopted to optimize experimental t...[Objective] The study was conducted to optimize the operation parameters of water control equipment for deep-litter beddings. [Method] A four-factor three-level orthogonal design was adopted to optimize experimental temperature, stopping time of aeration, aeration time and aeration rate by 9 groups of experiments, so as to improve the water removal efficiency of adopted mixed and reduce operation energy consumption. [Result] The average water contents in the mixed bedding under 3 temperatures decreased by 4.58% ±2.91%, 13.17% ±3.77% and 10.8% ±7.72%, respectively; the highest water removal efficiency could be achieved under an experimental temperature at 45 ℃, stopping time of aeration of 15 min, aeration time of 7 min, and an aeration rate at 4 m^3/min, which formed the optimal factor combination mode of the operation parameter of the water control equipment; the effects of various experimental factors on water content in the bedding were in order of aeration ratetemperatureaeration timestopping time of aeration; and the effects of various experimental factors on water removal efficiency in the bedding were in order of temperatureaeration rateaeration timestopping time of aeration. [Conclusion] After the optimization of operation parameters of the water control equipment for the deep-litter bedding, water removal efficiency of the mixed bedding could be improved, and the operation energy consumption of the equipment could be reduced.展开更多
Hexavalent chromium （Cr（VI）） pollution has become one of the most serious environmental problems today. One removal strategy comprises the microbial reduction of Cr（VI）, is regarded as a cost-effective biotechno...Hexavalent chromium （Cr（VI）） pollution has become one of the most serious environmental problems today. One removal strategy comprises the microbial reduction of Cr（VI）, is regarded as a cost-effective biotechnology for the treatment of high volume and low concentration complex wastewaters. In this work a yeast strain that exhibits high Cr（VI） resistance was isolated from soil sediment. The isolated yeast was identified as Pichia anomala by sequencing analysis. The yeast showed a remarkable capacity to completely reduce 25 and 50 mg/L of Cr（VI） in 48 h under aerobic conditions. The increase of initial Cr（VI） concentration influenced reduction, growth and specific growth rate. This strain also exhibited multiple heavy metal tolerance. The presence of anions and cations in the medium had a great influence on chromium reduction. Fractionation of the cells showed that the mechanism of Cr（VI） removal by this strain is ＂adsorption-coupled reduction＂ and the hexavalent chromate reductase activity was expressed constitutively. FTIR analysis of the biomass exposed to chromium showed that the binding process of the chromium ions involves the active participation of functional groups present in the external surface of biomass. High Cr（VI） concentration resistance and high Cr（VI） reducing ability of this strain make it a suitable candidate for bioremediation.展开更多
基金Supported by the Fund for Independent Innovation of Agricultural Sciences in Jiangsu Province(CX(13)3073)Jiangsu Science and Technology Support Program(BE2014-342-1)~~
文摘[Objective] The study was conducted to optimize the operation parameters of water control equipment for deep-litter beddings. [Method] A four-factor three-level orthogonal design was adopted to optimize experimental temperature, stopping time of aeration, aeration time and aeration rate by 9 groups of experiments, so as to improve the water removal efficiency of adopted mixed and reduce operation energy consumption. [Result] The average water contents in the mixed bedding under 3 temperatures decreased by 4.58% ±2.91%, 13.17% ±3.77% and 10.8% ±7.72%, respectively; the highest water removal efficiency could be achieved under an experimental temperature at 45 ℃, stopping time of aeration of 15 min, aeration time of 7 min, and an aeration rate at 4 m^3/min, which formed the optimal factor combination mode of the operation parameter of the water control equipment; the effects of various experimental factors on water content in the bedding were in order of aeration ratetemperatureaeration timestopping time of aeration; and the effects of various experimental factors on water removal efficiency in the bedding were in order of temperatureaeration rateaeration timestopping time of aeration. [Conclusion] After the optimization of operation parameters of the water control equipment for the deep-litter bedding, water removal efficiency of the mixed bedding could be improved, and the operation energy consumption of the equipment could be reduced.
文摘Hexavalent chromium （Cr（VI）） pollution has become one of the most serious environmental problems today. One removal strategy comprises the microbial reduction of Cr（VI）, is regarded as a cost-effective biotechnology for the treatment of high volume and low concentration complex wastewaters. In this work a yeast strain that exhibits high Cr（VI） resistance was isolated from soil sediment. The isolated yeast was identified as Pichia anomala by sequencing analysis. The yeast showed a remarkable capacity to completely reduce 25 and 50 mg/L of Cr（VI） in 48 h under aerobic conditions. The increase of initial Cr（VI） concentration influenced reduction, growth and specific growth rate. This strain also exhibited multiple heavy metal tolerance. The presence of anions and cations in the medium had a great influence on chromium reduction. Fractionation of the cells showed that the mechanism of Cr（VI） removal by this strain is ＂adsorption-coupled reduction＂ and the hexavalent chromate reductase activity was expressed constitutively. FTIR analysis of the biomass exposed to chromium showed that the binding process of the chromium ions involves the active participation of functional groups present in the external surface of biomass. High Cr（VI） concentration resistance and high Cr（VI） reducing ability of this strain make it a suitable candidate for bioremediation.
