For the last two decades the world has undergone a population explosion which has been accompanied by a speeding up of urbanization and land use for industrial and agricultural products. These involve a vast increase ...For the last two decades the world has undergone a population explosion which has been accompanied by a speeding up of urbanization and land use for industrial and agricultural products. These involve a vast increase in the discharge of pollutants into very different receiving water bodies, and have had adverse effects on the various components of the environment. For a long time, human has concerned a little of the natural environment. It is obvious that this variation in surface temperature of the earth increases the level of sea due to snowmelt. So climate change is manifested by many phenomena： floods, droughts, fires, tornadoes, cyclones, earthquakes, volcanic eruptions, diseases etc.. The statement today is dramatic. Entire regions were devastated and many rivers and lakes have become polluted around the world. Pollution has it nature which is hard to be absorbed. Where did the different pollutants come from？ What are the risks to the aquatic environment？ To prevent and combat the general decline of these ecosystems, it is important to distinguish and determine the effects of different sources of pollution and any changes that may suffer the physical environment. The climate depends primarily on changes in earth orbit parameters, which affect the solar radiation received by the earth surface. Therefore, human participates strongly to these changes, for example, pollution is the main reason to argue the greenhouse effect, an increase of anthropogenic carbon dioxide （CO2） into the atmosphere, which promotes global warming to the planet. These modifications are already applied in order to ensure durable development in water resources by controlling discharges into streams to preserve water resources for future generations and to ensure reconciliation between man-climate and environment.展开更多
In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective...In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective of the present study was to evaluate the impact of leachate from a dump on surface water systems. Physical, chemical, and bacteriological characteristics and the volume of leachate were measured. The site of study is located in Zinaprcuaro, Michoac^m, Mexico, and was chosen due to the water supplies were in line with the dump, thus conforming a system to test for movement of toxins. Leachate and water from three ponds located at different distances to the dump were sampled during three months of a year to measure physicochemical and bacteriological parameters, according to the standard methods of the American Public Health Association; the concentration of heavy metals was measured by atomic absorption spectrometry. Most characteristics exceed the maximum permissible limits established for the Mexican legislation regarding wastewater discharges and drinking water. Likewise, analysis of variance showed statistically significant differences between concentrations of pollutants in relation to the distance from the dump of sampled sites and with season of sampling, thus confirming the contamination of water by dump leachate.展开更多
Ten trace and heavy metals （Fe, Mn, Ni, Zn, Cu, Cd, As, Co, Cr and V） were analysed in sediments collected from nine stations at the Tema Port of Ghana, during the dry and wet seasons. Analysis of samples was done u...Ten trace and heavy metals （Fe, Mn, Ni, Zn, Cu, Cd, As, Co, Cr and V） were analysed in sediments collected from nine stations at the Tema Port of Ghana, during the dry and wet seasons. Analysis of samples was done using INAA （instrumental neutron activation analysis） for Mn, V, Cu, As and Cd, and AAS （atomic absorption spectrophotometry） for Fe, Cr, Zn, Ni and Co. The concentrations of metals in sediments followed the orders Fe 〉 V〉 Mn 〉 Cd 〉 Ni 〉 Zn 〉 Cu 〉As, for the dry season and Fe 〉 V 〉 Ni 〉 Cu 〉 Zn 〉 Mn 〉 Cd 〉As, for the wet season. Concentrations of Co and Cr were below detection limit, whiles Cu, Cd and Ni were found to be above the TELs （threshold effect levels） of NOAA＇s （National Oceanic and Atmospheric Administration＇s） SQuiRTs （screening quick reference tables） at most sites. Estimated enrichment factors for individual metals showed very high contamination of the port＇s sediments, with Cd occurring at all sites, and Cu, As, V and Ni occurring at some sites for both dry and wet seasons. Although sediments from the Tema Port were highly enriched with Cd, Cu, Ni and V above natural background levels, the overall PLI （pollution load index） per sampling station considering background values of the analysed elements indicated that metal pollution in the port＇s sediment is below 1, indicating relatively unpolluted sediment.展开更多
随着城市化和工业化的迅速发展,加之特殊的地形和天气气候条件,新疆地区面临严峻的大气污染问题。再分析数据时空连续性好、分辨率高,可有效弥补新疆地区地面观测站点稀疏不足的问题。文中聚焦新疆地区细颗粒物污染物(PM_(2.5)),采用中...随着城市化和工业化的迅速发展,加之特殊的地形和天气气候条件,新疆地区面临严峻的大气污染问题。再分析数据时空连续性好、分辨率高,可有效弥补新疆地区地面观测站点稀疏不足的问题。文中聚焦新疆地区细颗粒物污染物(PM_(2.5)),采用中国高分辨率高质量近地表空气污染物数据集(China High Air Pollutants,CHAP)和新疆35个国控站点观测数据,首先综合评估了CHAP PM_(2.5)质量浓度在新疆的适用性,进而深入分析了该地区2000-2022年PM_(2.5)质量浓度的时空分布和变化特征。结果表明,CHAP PM_(2.5)在新疆的适用性整体较高,在27个站点CHAP与站点实测值的相关系数均超过0.9,且北疆站点高于南疆;从平均绝对百分误差、均方根误差、标准偏差比等统计量来看,CHAP PM_(2.5)在相对洁净地区数值偏高约6.9%,在污染高值区偏低约4.8%。分析表明,2000-2022年新疆地区年均PM_(2.5)质量浓度整体呈下降趋势,由50μg/m^(3)降至37μg/m^(3),下降幅度约为26%,尤其在2016年后下降速度加快。从空间分布来看,PM_(2.5)质量浓度高值区分布在北疆的乌鲁木齐-昌吉-石河子城市群和南疆的塔里木盆地。南、北疆地区PM_(2.5)质量浓度的季节变化差异明显,南疆地区在春季浓度较高,最大均值(94μg/m^(3))出现在4月份;北疆地区在冬季浓度较高,最大均值(62μg/m^(3))出现在1月份。文中研究可为新疆大气污染重点区域的机理研究和防治措施的制定实施提供科学参考。展开更多
文摘For the last two decades the world has undergone a population explosion which has been accompanied by a speeding up of urbanization and land use for industrial and agricultural products. These involve a vast increase in the discharge of pollutants into very different receiving water bodies, and have had adverse effects on the various components of the environment. For a long time, human has concerned a little of the natural environment. It is obvious that this variation in surface temperature of the earth increases the level of sea due to snowmelt. So climate change is manifested by many phenomena： floods, droughts, fires, tornadoes, cyclones, earthquakes, volcanic eruptions, diseases etc.. The statement today is dramatic. Entire regions were devastated and many rivers and lakes have become polluted around the world. Pollution has it nature which is hard to be absorbed. Where did the different pollutants come from？ What are the risks to the aquatic environment？ To prevent and combat the general decline of these ecosystems, it is important to distinguish and determine the effects of different sources of pollution and any changes that may suffer the physical environment. The climate depends primarily on changes in earth orbit parameters, which affect the solar radiation received by the earth surface. Therefore, human participates strongly to these changes, for example, pollution is the main reason to argue the greenhouse effect, an increase of anthropogenic carbon dioxide （CO2） into the atmosphere, which promotes global warming to the planet. These modifications are already applied in order to ensure durable development in water resources by controlling discharges into streams to preserve water resources for future generations and to ensure reconciliation between man-climate and environment.
文摘In Mexico, hazardous and non-hazardous urban solid wastes are commonly disposed of in dumps. Inappropriate waste disposal makes solid waste disposal sites potential sources of pollution and health risks. The objective of the present study was to evaluate the impact of leachate from a dump on surface water systems. Physical, chemical, and bacteriological characteristics and the volume of leachate were measured. The site of study is located in Zinaprcuaro, Michoac^m, Mexico, and was chosen due to the water supplies were in line with the dump, thus conforming a system to test for movement of toxins. Leachate and water from three ponds located at different distances to the dump were sampled during three months of a year to measure physicochemical and bacteriological parameters, according to the standard methods of the American Public Health Association; the concentration of heavy metals was measured by atomic absorption spectrometry. Most characteristics exceed the maximum permissible limits established for the Mexican legislation regarding wastewater discharges and drinking water. Likewise, analysis of variance showed statistically significant differences between concentrations of pollutants in relation to the distance from the dump of sampled sites and with season of sampling, thus confirming the contamination of water by dump leachate.
文摘Ten trace and heavy metals （Fe, Mn, Ni, Zn, Cu, Cd, As, Co, Cr and V） were analysed in sediments collected from nine stations at the Tema Port of Ghana, during the dry and wet seasons. Analysis of samples was done using INAA （instrumental neutron activation analysis） for Mn, V, Cu, As and Cd, and AAS （atomic absorption spectrophotometry） for Fe, Cr, Zn, Ni and Co. The concentrations of metals in sediments followed the orders Fe 〉 V〉 Mn 〉 Cd 〉 Ni 〉 Zn 〉 Cu 〉As, for the dry season and Fe 〉 V 〉 Ni 〉 Cu 〉 Zn 〉 Mn 〉 Cd 〉As, for the wet season. Concentrations of Co and Cr were below detection limit, whiles Cu, Cd and Ni were found to be above the TELs （threshold effect levels） of NOAA＇s （National Oceanic and Atmospheric Administration＇s） SQuiRTs （screening quick reference tables） at most sites. Estimated enrichment factors for individual metals showed very high contamination of the port＇s sediments, with Cd occurring at all sites, and Cu, As, V and Ni occurring at some sites for both dry and wet seasons. Although sediments from the Tema Port were highly enriched with Cd, Cu, Ni and V above natural background levels, the overall PLI （pollution load index） per sampling station considering background values of the analysed elements indicated that metal pollution in the port＇s sediment is below 1, indicating relatively unpolluted sediment.
文摘随着城市化和工业化的迅速发展,加之特殊的地形和天气气候条件,新疆地区面临严峻的大气污染问题。再分析数据时空连续性好、分辨率高,可有效弥补新疆地区地面观测站点稀疏不足的问题。文中聚焦新疆地区细颗粒物污染物(PM_(2.5)),采用中国高分辨率高质量近地表空气污染物数据集(China High Air Pollutants,CHAP)和新疆35个国控站点观测数据,首先综合评估了CHAP PM_(2.5)质量浓度在新疆的适用性,进而深入分析了该地区2000-2022年PM_(2.5)质量浓度的时空分布和变化特征。结果表明,CHAP PM_(2.5)在新疆的适用性整体较高,在27个站点CHAP与站点实测值的相关系数均超过0.9,且北疆站点高于南疆;从平均绝对百分误差、均方根误差、标准偏差比等统计量来看,CHAP PM_(2.5)在相对洁净地区数值偏高约6.9%,在污染高值区偏低约4.8%。分析表明,2000-2022年新疆地区年均PM_(2.5)质量浓度整体呈下降趋势,由50μg/m^(3)降至37μg/m^(3),下降幅度约为26%,尤其在2016年后下降速度加快。从空间分布来看,PM_(2.5)质量浓度高值区分布在北疆的乌鲁木齐-昌吉-石河子城市群和南疆的塔里木盆地。南、北疆地区PM_(2.5)质量浓度的季节变化差异明显,南疆地区在春季浓度较高,最大均值(94μg/m^(3))出现在4月份;北疆地区在冬季浓度较高,最大均值(62μg/m^(3))出现在1月份。文中研究可为新疆大气污染重点区域的机理研究和防治措施的制定实施提供科学参考。
