This paper conducts a comparative analysis of the anti-wetting properties and degassing performance of both homemade and commercial membranes.Additionally,it introduces a unique approach to hydrophobic modification of...This paper conducts a comparative analysis of the anti-wetting properties and degassing performance of both homemade and commercial membranes.Additionally,it introduces a unique approach to hydrophobic modification of high-flux membranes.The study involved the utilization of Hyflon AD40L for multiple coatings on the surface of polypropylene(PP)hollow fiber membranes.Several variables,including modification solution concentration,temperature,coating duration,number of coating cycles,polymer type,and the choice and concentration of the pore-blocking agent,were systematically investigated to establish the optimal modification process.Characterization of the modified membrane and degassing experiments revealed significant improvements.Specifically,the contact angle increased from 95.5°to 113.1°,while the trans-membrane differential pressure surged from 10.7 kPa to 154.6 kPa,marking a remarkable 14.4-fold enhancement.This enhancement is attributed to the improved antiwetting capabilities of the modified membrane.In the degassing experiments,the modified membrane-based module demonstrated an impressive 95.0%dissolved oxygen removal rate,with a corresponding mass transfer coefficient reaching 18.01×10^(-3)m·h^(-1).These results underscore the substantial potential of the Hyflon AD40 L/PP membrane for applications in membrane degassing.展开更多
Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activa...Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared （FTIR） spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.展开更多
Natural organic matter（NOM）, present in natural waters and wastewater, decreases adsorption of micropollutants, increasing treatment costs. This research investigated mechanisms of competition for non-imprinted poly...Natural organic matter（NOM）, present in natural waters and wastewater, decreases adsorption of micropollutants, increasing treatment costs. This research investigated mechanisms of competition for non-imprinted polymers（NIPs） and activated carbon with humic acid and wastewater. Three different types of activated carbons（Norit PAC 200,Darco KB-M, and Darco S-51） were used for comparison with the NIP. The lower surface area and micropore to mesopore ratio of the NIP led to decreased adsorption capacity in comparison to the activated carbons. In addition, experiments were conducted for single-solute adsorption of Methylene Blue（MB） dye, simultaneous adsorption with humic acid and wastewater, and pre-loading with humic acid and wastewater followed by adsorption of MB dye using NIP and Norit PAC 200. Both the NIP and PAC 200 showed significant decreases of 27% for NIP（p = 0.087） and 29% for PAC 200（p = 0.096） during simultaneous exposure to humic acid and MB dye. There was no corresponding decrease for NIP or PAC 200 pre-loaded with humic acid and then exposed to MB. In fact, for PAC 200, the adsorption capacity of the activated carbon increased when it was pre-loaded with humic acid by 39%（p = 0.0005）. For wastewater, the NIP showed no significant increase or decrease in adsorption capacity during either simultaneous exposure or pre-loading. The adsorption capacity of PAC 200 increased by 40%（p = 0.001） for simultaneous exposure to wastewater and MB. Pre-loading with wastewater had no effect on MB adsorption by PAC 200.展开更多
CuO/γ-Al2O3 sorbents were prepared by means of impregnation. Thermogravimetric technique was used to study the sulfation of CuO/γ-Al2O3 sorbents. The sulfation tests were performed using gas containing 0.1%-0.9% SO2...CuO/γ-Al2O3 sorbents were prepared by means of impregnation. Thermogravimetric technique was used to study the sulfation of CuO/γ-Al2O3 sorbents. The sulfation tests were performed using gas containing 0.1%-0.9% SO2, 5% O2, 3% H2O steam, and N2 as the balance. Experimental conditions including temperature, SO2 concentration and pore structure were studied. The sulfation experiment results show that the sulfation reaction rate increases with increasing temperature and SO2 concentration, and the surface and pore volume decrease after sulfation. Sulfation kinetics analysis shows that the reaction between CuO/γ-Al2O3 and SO2 obeys pore-blocking model well. Proportionality (pore-blocking constant) 1/λ decreases with increasing temperature. The activation energy and reaction order with respect to SO2 obtained are 37.9 kJ/mol and the first order, respectively. The existing state of CuO exerts an influence on activation energy.展开更多
基金financial support of the National Key Research and Development Program of China(2020YFC0862903)the National Natural Science Foundation of China(22078146)+2 种基金the Key Research and Development program of Jiangsu Province(BE2021022)the Materials-Oriented Chemical Engineering State Key Laboratory Program(KL19-04)the Natural Science Foundation of Jiangsu Province(BK20200091).
文摘This paper conducts a comparative analysis of the anti-wetting properties and degassing performance of both homemade and commercial membranes.Additionally,it introduces a unique approach to hydrophobic modification of high-flux membranes.The study involved the utilization of Hyflon AD40L for multiple coatings on the surface of polypropylene(PP)hollow fiber membranes.Several variables,including modification solution concentration,temperature,coating duration,number of coating cycles,polymer type,and the choice and concentration of the pore-blocking agent,were systematically investigated to establish the optimal modification process.Characterization of the modified membrane and degassing experiments revealed significant improvements.Specifically,the contact angle increased from 95.5°to 113.1°,while the trans-membrane differential pressure surged from 10.7 kPa to 154.6 kPa,marking a remarkable 14.4-fold enhancement.This enhancement is attributed to the improved antiwetting capabilities of the modified membrane.In the degassing experiments,the modified membrane-based module demonstrated an impressive 95.0%dissolved oxygen removal rate,with a corresponding mass transfer coefficient reaching 18.01×10^(-3)m·h^(-1).These results underscore the substantial potential of the Hyflon AD40 L/PP membrane for applications in membrane degassing.
基金Project supported by the University Doctorial Research Foundation.Ministry of Education of China(No.20030141022).
文摘Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared （FTIR） spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.
基金funded by the Natural Sciences and Engineering Council of Canada (NSERC RGPIN 06246-2016) under the Discovery Grant program
文摘Natural organic matter（NOM）, present in natural waters and wastewater, decreases adsorption of micropollutants, increasing treatment costs. This research investigated mechanisms of competition for non-imprinted polymers（NIPs） and activated carbon with humic acid and wastewater. Three different types of activated carbons（Norit PAC 200,Darco KB-M, and Darco S-51） were used for comparison with the NIP. The lower surface area and micropore to mesopore ratio of the NIP led to decreased adsorption capacity in comparison to the activated carbons. In addition, experiments were conducted for single-solute adsorption of Methylene Blue（MB） dye, simultaneous adsorption with humic acid and wastewater, and pre-loading with humic acid and wastewater followed by adsorption of MB dye using NIP and Norit PAC 200. Both the NIP and PAC 200 showed significant decreases of 27% for NIP（p = 0.087） and 29% for PAC 200（p = 0.096） during simultaneous exposure to humic acid and MB dye. There was no corresponding decrease for NIP or PAC 200 pre-loaded with humic acid and then exposed to MB. In fact, for PAC 200, the adsorption capacity of the activated carbon increased when it was pre-loaded with humic acid by 39%（p = 0.0005）. For wastewater, the NIP showed no significant increase or decrease in adsorption capacity during either simultaneous exposure or pre-loading. The adsorption capacity of PAC 200 increased by 40%（p = 0.001） for simultaneous exposure to wastewater and MB. Pre-loading with wastewater had no effect on MB adsorption by PAC 200.
基金Project(u0837604) supported by United Foundation of Natural Science Foundation of China and Yunnan ProvinceProject(08Z0017) supported by the Provincial Education Department of Yunnan Province, China+1 种基金Project(2008ZC011M) supported by the Applied Fundamental Research of Yunnan Province, ChinaProject(2008-06) supported by the Scientific Research Foundation of Kunming University of Science and Technology
文摘CuO/γ-Al2O3 sorbents were prepared by means of impregnation. Thermogravimetric technique was used to study the sulfation of CuO/γ-Al2O3 sorbents. The sulfation tests were performed using gas containing 0.1%-0.9% SO2, 5% O2, 3% H2O steam, and N2 as the balance. Experimental conditions including temperature, SO2 concentration and pore structure were studied. The sulfation experiment results show that the sulfation reaction rate increases with increasing temperature and SO2 concentration, and the surface and pore volume decrease after sulfation. Sulfation kinetics analysis shows that the reaction between CuO/γ-Al2O3 and SO2 obeys pore-blocking model well. Proportionality (pore-blocking constant) 1/λ decreases with increasing temperature. The activation energy and reaction order with respect to SO2 obtained are 37.9 kJ/mol and the first order, respectively. The existing state of CuO exerts an influence on activation energy.
