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
The goal of the present study was to investigate the influence of latex particle aggregation on membrane fouling attachments and the ultrafiltration performance of simulated latex effluent using Cetyltrimethyl Ammoniu...The goal of the present study was to investigate the influence of latex particle aggregation on membrane fouling attachments and the ultrafiltration performance of simulated latex effluent using Cetyltrimethyl Ammonium Bromide（CTAB） as a cationic surfactant. Hydrophilic polysulfone and ultrafilic flat heterogeneous membranes, with molecular weight cut off（MWCO） of 60,000 and 100,000, respectively, as well as hydrophobic polyvinylidene difluoride with MWCO of 100,000, were used under a constant flow rate and cross-flow mode in ultrafiltration of latex solution. In addition, a polycarbonate flat membrane with uniform pore size of 0.05 μm was likewise used during the experiment. The effects of CTAB on the latex particle size distribution were investigated at various concentrations, different treatment times, and diverse agitation duration times. The effects of CTAB on the zeta potential of membrane surfaces and latex particles were also investigated. The data obtained indicate that the particle size distribution of treated latex effluent experienced significant shifts in the peaks toward a larger size range caused by the aggregation of particles. As a result, the mass of fouling contributing to pore blocking and the irreversible fouling were noticeably reduced. The optimum results occurred in the instance when CTAB was added at the critical micelle concentration of 0.36 g/L, for the duration of 10 min and with minimal agitation. Notably, a higher stirring rate had an overall negative effect on the membrane fouling minimization.展开更多
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.
基金support from Natural Science and Engineering Research Council of Canada(NSERC)(RGPIN/216939-2013)The assistance and facilities provided by the Department of Chemical Engineering,Ryerson University
文摘The goal of the present study was to investigate the influence of latex particle aggregation on membrane fouling attachments and the ultrafiltration performance of simulated latex effluent using Cetyltrimethyl Ammonium Bromide（CTAB） as a cationic surfactant. Hydrophilic polysulfone and ultrafilic flat heterogeneous membranes, with molecular weight cut off（MWCO） of 60,000 and 100,000, respectively, as well as hydrophobic polyvinylidene difluoride with MWCO of 100,000, were used under a constant flow rate and cross-flow mode in ultrafiltration of latex solution. In addition, a polycarbonate flat membrane with uniform pore size of 0.05 μm was likewise used during the experiment. The effects of CTAB on the latex particle size distribution were investigated at various concentrations, different treatment times, and diverse agitation duration times. The effects of CTAB on the zeta potential of membrane surfaces and latex particles were also investigated. The data obtained indicate that the particle size distribution of treated latex effluent experienced significant shifts in the peaks toward a larger size range caused by the aggregation of particles. As a result, the mass of fouling contributing to pore blocking and the irreversible fouling were noticeably reduced. The optimum results occurred in the instance when CTAB was added at the critical micelle concentration of 0.36 g/L, for the duration of 10 min and with minimal agitation. Notably, a higher stirring rate had an overall negative effect on the membrane fouling minimization.
基金supported by the Fundamental Research Funds for the Central Universities(222201718003)Projects of the Shanghai Science and Technology Committee(17DZ1202604)
