In the present study,the effects of relative humidity on filtrating coal-fired fly ash with hydrophobic poly tetra fluoroethylene(PTFE) membranes were investigated.The intergranular force of particulate matter at diff...In the present study,the effects of relative humidity on filtrating coal-fired fly ash with hydrophobic poly tetra fluoroethylene(PTFE) membranes were investigated.The intergranular force of particulate matter at different RH conditions was measured by analyzing the critical angle between particles.Effects of humidity(from 30% to 70%) on filtration pressure drop and membrane fouling conditions were characterized.It was found the membrane showed optimal filtration resistance of 530 Pa at RH of 60% and the gas permeance can be maintained at 1440 m^(3)·m^(-2)·h^(-1)·kPa^(-1).Moreover,to optimize the operation parameters for this filtration system,effects of fly ash concentration,diameter,membrane pore size,and gas velocities were systematically investigated.展开更多
Passive sampling technology has good application prospects for monitoring trace pollutants in aquatic environments.Further research on the sampling mechanism of this technology is essential to improve the measurement ...Passive sampling technology has good application prospects for monitoring trace pollutants in aquatic environments.Further research on the sampling mechanism of this technology is essential to improve the measurement accuracy and extend the application scope of this approach.In this study,adsorption and permeation experiments were performed to investigate the sorption and mass transfer properties of five chiral pharmaceuticals at the enantiomeric level on polyethersulfone(PES)and polytetrafluoroethylene(PTFE)membranes used in a polar organic chemical integrative sampler.Batch adsorption experiments showed that the PES membrane had an adsorption phenomenon for most selected pollutants and an insignificant sorption behavior was observed for all selected pharmaceuticals on the PTFE membrane except for R(S)-fluoxetine.The diffusion coefficients of selected pharmaceuticals onto the PTFE membrane were approximately one order of magnitude higher than those onto the PES membrane.The permeation experiment indicated that under different hydraulic conditions,the change of the relative pollutant concentration through the PTFE membrane for the composite pollutant system was more obvious than that for the single pollutant system,and mass transfer hysteresis exists for both contaminant systems through PES membranes.Using the first-order equation or 3-component model to estimate the overall mass transfer coefficients,the results showed that the overall mass transfer coefficient values of pollutants in the composite pollutant system onto both membranes were higher than those in the single pollutant system.This parameter was mainly influenced by the synergistic effects of the multi-analyte interaction and diminished water boundary layers during the mass transfer process.展开更多
基金supported by the National Key Research and Development Project of China (2018YFE0203500)the High-end Research and Training Project for Specialty Leading Person of Jiangsu Higher Vocational Colleges (2020GRGDYX039)the Qing Lan Project of Jiangsu Colleges。
文摘In the present study,the effects of relative humidity on filtrating coal-fired fly ash with hydrophobic poly tetra fluoroethylene(PTFE) membranes were investigated.The intergranular force of particulate matter at different RH conditions was measured by analyzing the critical angle between particles.Effects of humidity(from 30% to 70%) on filtration pressure drop and membrane fouling conditions were characterized.It was found the membrane showed optimal filtration resistance of 530 Pa at RH of 60% and the gas permeance can be maintained at 1440 m^(3)·m^(-2)·h^(-1)·kPa^(-1).Moreover,to optimize the operation parameters for this filtration system,effects of fly ash concentration,diameter,membrane pore size,and gas velocities were systematically investigated.
基金supported by the National Natural Science Foundation of China (No.41977377)。
文摘Passive sampling technology has good application prospects for monitoring trace pollutants in aquatic environments.Further research on the sampling mechanism of this technology is essential to improve the measurement accuracy and extend the application scope of this approach.In this study,adsorption and permeation experiments were performed to investigate the sorption and mass transfer properties of five chiral pharmaceuticals at the enantiomeric level on polyethersulfone(PES)and polytetrafluoroethylene(PTFE)membranes used in a polar organic chemical integrative sampler.Batch adsorption experiments showed that the PES membrane had an adsorption phenomenon for most selected pollutants and an insignificant sorption behavior was observed for all selected pharmaceuticals on the PTFE membrane except for R(S)-fluoxetine.The diffusion coefficients of selected pharmaceuticals onto the PTFE membrane were approximately one order of magnitude higher than those onto the PES membrane.The permeation experiment indicated that under different hydraulic conditions,the change of the relative pollutant concentration through the PTFE membrane for the composite pollutant system was more obvious than that for the single pollutant system,and mass transfer hysteresis exists for both contaminant systems through PES membranes.Using the first-order equation or 3-component model to estimate the overall mass transfer coefficients,the results showed that the overall mass transfer coefficient values of pollutants in the composite pollutant system onto both membranes were higher than those in the single pollutant system.This parameter was mainly influenced by the synergistic effects of the multi-analyte interaction and diminished water boundary layers during the mass transfer process.
