First, the date palm kernel is used to produce granular activated carbon （GAC） by a physiochemical activation process. The process involves six steps： washing, drying, crushing, sieving, carbonization, and activati...First, the date palm kernel is used to produce granular activated carbon （GAC） by a physiochemical activation process. The process involves six steps： washing, drying, crushing, sieving, carbonization, and activation. Secondly, the ability of the produced GAC to remove pollutants is examined through batch experiments of residual chlorine adsorption whereas the equilibrium isotherm experimental data are tested for the Langmuir and Freundlich isotherms equations. Thirdly, the experimental and theoretical study of dynamic adsorption process and the effect of major operating parameters on dynamic adsorption are investigated. The results show that the Langmuir isotherm gives the best fitting to experimental data, which indicates that the residual chlorine adsorption can be characterized by mono layer adsorption behavior. The produced GAC has a great potential as an adsorbent for residual chlorine in water systems and it can compete favorably with the conventional adsorbents. The Thomas extended model with combined mass transfer resistances is used for verifying the experimental results and the results show that the proposed model coincides well with the experimental data of the dynamic adsorption process.展开更多
以自动生成测地线活动轮廓(geodesic active contour,GAC)模型的初始曲线及改进其外力为出发点,提出一种基于LiDAR点云和随机影像数据,利用改进的GAC模型进行建筑物边界提取的方案。首先利用形态学交替序贯滤波自动获得模型演化的初始曲...以自动生成测地线活动轮廓(geodesic active contour,GAC)模型的初始曲线及改进其外力为出发点,提出一种基于LiDAR点云和随机影像数据,利用改进的GAC模型进行建筑物边界提取的方案。首先利用形态学交替序贯滤波自动获得模型演化的初始曲线;进而利用LiDAR深度梯度影像改进模型演化的外力,得到了改进的测地线活动轮廓(improved geodesic active contour,IGAC)模型。仿真试验表明,采用IGAC模型,可抑制弱边界泄漏,并提高建筑物边界提取的完整性和形状精确度。展开更多
The elemental composition and bacteria attached in particles were investigated during granular activated carbon （GAC） filtration.The experimental results showed that trapped influent particles could form new,larger ...The elemental composition and bacteria attached in particles were investigated during granular activated carbon （GAC） filtration.The experimental results showed that trapped influent particles could form new,larger particles on GAC surface.The sloughing of individuals off GAC surface caused an increase in effluent particles in the size range from 5 to 25 μm.The selectivity for element removal in GAC filters caused an increasing proportion of metallic elements in the effluent particles.The distribution of molar ratio indicated a complicated composition for large particles,involving organic and inorganic substances.The organic proportion accounted for 40% of total carbon attached to the particles.Compared with dissolved carbon,there was potential for the formation of trihalomethanes by organic carbon attached to particles,especially for those with size larger than 10 μm.The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 μm.The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection.The residual attached bacteria after chorine disinfection was increased to 10 2-10 3 CFU/mL within 24 hours at 25°C.展开更多
Comparative experiments on the inactivation of Copepod were investigated in southern China. The 100% of inactivation effect may be attained by 3.0 mg/L of ozone for contacting time of 25 min, whereas 0.5 mg/L of dosag...Comparative experiments on the inactivation of Copepod were investigated in southern China. The 100% of inactivation effect may be attained by 3.0 mg/L of ozone for contacting time of 25 min, whereas 0.5 mg/L of dosage resulted in only 30% of inactivation rate. Copepod may not be completely inactivated by ozone oxidation for feasible dosage limited by higher bromide in raw water. The favorable environment of granular activated carbon （GAC） filter provided Copepod with conditions for excess propagation, The disinfection experimental results show that the inactivation rate is 90% by 2.0 mg/L of chloramines for contacting time of 30 min, whereas only 70% is attained with chlorine. The GC-MS examination indicates that the total organic substance is increased to 92 specie： inciuding 13 sorts of halogenated hydrocarbon by chlorine disnfection, which is more than that of chloramines. More products of bromiinated trihalomethanes occur in treated water by chlorine, disinfection and total amount of THMs is 3 times as high as that of chloramines.展开更多
利用沸石-活性炭组合填料生物滤池对黄河兰州段微污染原水预处理效果进行了试验研究。采用上向流方式,原水经沸石-活性炭组合填料生物滤池,通过自然挂膜的方法,使生物膜附着生长在填料表面,经比较试验,在不同水力停留时间下,检测污染物...利用沸石-活性炭组合填料生物滤池对黄河兰州段微污染原水预处理效果进行了试验研究。采用上向流方式,原水经沸石-活性炭组合填料生物滤池,通过自然挂膜的方法,使生物膜附着生长在填料表面,经比较试验,在不同水力停留时间下,检测污染物的去除效果。进而在气水比、水力停留时间一定的条件下,观察其耐冲击负荷能力,并对沸石-活性炭组合填料滤池与沸石生物滤池和活性炭生物滤池的除污效果进行比较。结果表明：水力停留时间为40 m in,气水比为1∶1,水温在25-30℃的试验条件下,组合填料生物滤池对NH3-N,CODcr,UV254,浊度和锰的平均去除率分别为94.77%,39.92%,10.17%,70.10%,91.30%。因此,沸石-活性炭组合填料生物滤池相对于沸石生物滤池而言,其对微污染原水的预处理效果较明显,且具有较强的耐冲击负荷能力。展开更多
基金The National Natural Science Foundation of China(No. 51078074)
文摘First, the date palm kernel is used to produce granular activated carbon （GAC） by a physiochemical activation process. The process involves six steps： washing, drying, crushing, sieving, carbonization, and activation. Secondly, the ability of the produced GAC to remove pollutants is examined through batch experiments of residual chlorine adsorption whereas the equilibrium isotherm experimental data are tested for the Langmuir and Freundlich isotherms equations. Thirdly, the experimental and theoretical study of dynamic adsorption process and the effect of major operating parameters on dynamic adsorption are investigated. The results show that the Langmuir isotherm gives the best fitting to experimental data, which indicates that the residual chlorine adsorption can be characterized by mono layer adsorption behavior. The produced GAC has a great potential as an adsorbent for residual chlorine in water systems and it can compete favorably with the conventional adsorbents. The Thomas extended model with combined mass transfer resistances is used for verifying the experimental results and the results show that the proposed model coincides well with the experimental data of the dynamic adsorption process.
文摘以自动生成测地线活动轮廓(geodesic active contour,GAC)模型的初始曲线及改进其外力为出发点,提出一种基于LiDAR点云和随机影像数据,利用改进的GAC模型进行建筑物边界提取的方案。首先利用形态学交替序贯滤波自动获得模型演化的初始曲线;进而利用LiDAR深度梯度影像改进模型演化的外力,得到了改进的测地线活动轮廓(improved geodesic active contour,IGAC)模型。仿真试验表明,采用IGAC模型,可抑制弱边界泄漏,并提高建筑物边界提取的完整性和形状精确度。
基金supported by the National Natural Science Foundation of China (No. 50778062)the Hi-Tech Research and Development Program (863) of China (No.2006AA06Z311)
文摘The elemental composition and bacteria attached in particles were investigated during granular activated carbon （GAC） filtration.The experimental results showed that trapped influent particles could form new,larger particles on GAC surface.The sloughing of individuals off GAC surface caused an increase in effluent particles in the size range from 5 to 25 μm.The selectivity for element removal in GAC filters caused an increasing proportion of metallic elements in the effluent particles.The distribution of molar ratio indicated a complicated composition for large particles,involving organic and inorganic substances.The organic proportion accounted for 40% of total carbon attached to the particles.Compared with dissolved carbon,there was potential for the formation of trihalomethanes by organic carbon attached to particles,especially for those with size larger than 10 μm.The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 μm.The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection.The residual attached bacteria after chorine disinfection was increased to 10 2-10 3 CFU/mL within 24 hours at 25°C.
基金National Natural Science Foundation of China(No.50808065)National Key High-Tech Program(863) of China(No.2006AA06Z311)Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Open Project,China(No.2006KJ006)
文摘Comparative experiments on the inactivation of Copepod were investigated in southern China. The 100% of inactivation effect may be attained by 3.0 mg/L of ozone for contacting time of 25 min, whereas 0.5 mg/L of dosage resulted in only 30% of inactivation rate. Copepod may not be completely inactivated by ozone oxidation for feasible dosage limited by higher bromide in raw water. The favorable environment of granular activated carbon （GAC） filter provided Copepod with conditions for excess propagation, The disinfection experimental results show that the inactivation rate is 90% by 2.0 mg/L of chloramines for contacting time of 30 min, whereas only 70% is attained with chlorine. The GC-MS examination indicates that the total organic substance is increased to 92 specie： inciuding 13 sorts of halogenated hydrocarbon by chlorine disnfection, which is more than that of chloramines. More products of bromiinated trihalomethanes occur in treated water by chlorine, disinfection and total amount of THMs is 3 times as high as that of chloramines.
文摘利用沸石-活性炭组合填料生物滤池对黄河兰州段微污染原水预处理效果进行了试验研究。采用上向流方式,原水经沸石-活性炭组合填料生物滤池,通过自然挂膜的方法,使生物膜附着生长在填料表面,经比较试验,在不同水力停留时间下,检测污染物的去除效果。进而在气水比、水力停留时间一定的条件下,观察其耐冲击负荷能力,并对沸石-活性炭组合填料滤池与沸石生物滤池和活性炭生物滤池的除污效果进行比较。结果表明：水力停留时间为40 m in,气水比为1∶1,水温在25-30℃的试验条件下,组合填料生物滤池对NH3-N,CODcr,UV254,浊度和锰的平均去除率分别为94.77%,39.92%,10.17%,70.10%,91.30%。因此,沸石-活性炭组合填料生物滤池相对于沸石生物滤池而言,其对微污染原水的预处理效果较明显,且具有较强的耐冲击负荷能力。
