The photocatalytic degradation of Rhodamine B （RhB） was carried out using TiO2 supported on activated carbon （TiO2-AC） under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X...The photocatalytic degradation of Rhodamine B （RhB） was carried out using TiO2 supported on activated carbon （TiO2-AC） under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM） and Brunauer-Emmett-Teller （BET）. In the process of microwave-enhanced photocatalysis （MPC）, RhB （30 mg/L） was almost completely decoloured in 10 min, and the mineralization efficiency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry （GC/MS） and liquid chromatography/mass spectrometry （LC/MS） identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates （N,N-diethyl-N＇-ethyl-rhodamine （DER））, oxalic acid, malonic acid, snccinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.展开更多
Groundwater levels are gradually declining in basins around the world due to anthropogenic and natural factors.Climate is not the only factor contributing to change in groundwater levels,population growth and economic...Groundwater levels are gradually declining in basins around the world due to anthropogenic and natural factors.Climate is not the only factor contributing to change in groundwater levels,population growth and economic progress are leading to increased water demand.Areas used for agricultural irrigation are expanding,necessitating the use of artificial groundwater recharge as a method to sustain pumping and enhance storage.The present study delineates potential locations of significant groundwater resources that already exist using a geostatistical approach as a method to identify potential groundwater recharge zones.The Multi-Influencing Factors(MIF)technique was applied to determine the relationship between different landscape and climatic factors that influence groundwater recharge.Factors include topography,climate,hydrogeology,population,economic change,and geology.Integration of these factors enabled the identification of potential locations of groundwater suitable for artificial recharge efforts based on weights derived through the MIF technique.We applied these weights to derive a groundwater recharge index(GRI)map.The map was delineated into three groundwater recharge zones classified by their potential areal coverage as a metric for recharge suitability,namely low,medium and high suitability,occupying areas of 8625 km2(30.06%),9082 km2(31.65%),and 10,989 km~2(38.29%),respectively.Our findings have important implications for designing sustainable groundwater development and land-use plans for the coming century.展开更多
基金supported by the National Natural Science Foundation of China (No. 20707009)the Jiangsu Province Social Development Foundation (No.BS2007051)+1 种基金the Opening Foundation (WTWER0713) of Engineering Research Center for Water Treatment and Water Remediation of the Ministry of Education of Chinathe State Key Laboratory of Pollution Control and Resource Reuse Opening Foundation (No. PCRRCF07003).
文摘The photocatalytic degradation of Rhodamine B （RhB） was carried out using TiO2 supported on activated carbon （TiO2-AC） under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM） and Brunauer-Emmett-Teller （BET）. In the process of microwave-enhanced photocatalysis （MPC）, RhB （30 mg/L） was almost completely decoloured in 10 min, and the mineralization efficiency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry （GC/MS） and liquid chromatography/mass spectrometry （LC/MS） identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates （N,N-diethyl-N＇-ethyl-rhodamine （DER））, oxalic acid, malonic acid, snccinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.
文摘Groundwater levels are gradually declining in basins around the world due to anthropogenic and natural factors.Climate is not the only factor contributing to change in groundwater levels,population growth and economic progress are leading to increased water demand.Areas used for agricultural irrigation are expanding,necessitating the use of artificial groundwater recharge as a method to sustain pumping and enhance storage.The present study delineates potential locations of significant groundwater resources that already exist using a geostatistical approach as a method to identify potential groundwater recharge zones.The Multi-Influencing Factors(MIF)technique was applied to determine the relationship between different landscape and climatic factors that influence groundwater recharge.Factors include topography,climate,hydrogeology,population,economic change,and geology.Integration of these factors enabled the identification of potential locations of groundwater suitable for artificial recharge efforts based on weights derived through the MIF technique.We applied these weights to derive a groundwater recharge index(GRI)map.The map was delineated into three groundwater recharge zones classified by their potential areal coverage as a metric for recharge suitability,namely low,medium and high suitability,occupying areas of 8625 km2(30.06%),9082 km2(31.65%),and 10,989 km~2(38.29%),respectively.Our findings have important implications for designing sustainable groundwater development and land-use plans for the coming century.
