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51.
去除废水中重金属的低成本吸附剂:生物质和地质材料的环境利用 总被引:27,自引:0,他引:27
经济、有效、易获得的生物质和地质材料 (及二者的废弃物 )可用来取代传统的活性炭或离子交换树脂用于去除废水中的重金属。已经公开发表的低成本吸附剂主要可分为两类 :(1)生物质 (包括林业和农业的废弃物 ) :树皮 /富含丹宁酸的物质 ,木质素 ,几丁质 /甲壳质 ,死的生物体 ,苔藓 ,海草 /海藻 /褐藻酸 ,废弃的茶叶 ,稻壳 ,羊毛 ,棉花等 ;(2 )地质材料 (包括矿物利用后的工业废弃物 ) :沸石 ,粘土 ,泥炭 ,有铁氧化物包壳的砂 ,粉煤灰等。其中 ,对于重金属具有强吸附能力的吸附剂有甲壳质、沸石和木质素 ,例如 ,它们对一些重金属的最大吸附能力分别为 :甲壳质对Cd ,Hg ,Pb分别为 5 5 8,112 3 ,796mg/g ,沸石对Pb为 15 5 4mg/g ,木质素对Pb为 15 87mg/g。地质材料的环境利用值得引起地学界和环境工程界更广泛的重视。基于地质材料和水岩相互作用机理的环境污染控制技术有望成为 2 1世纪重要的环保替代技术。由于缺少连续的可比性强的成本信息 ,要比较不同的生物质和地质材料的成本和吸附性能仍较困难。尽管已对低成本吸附剂领域进行了很多研究 ,但要更好地了解低成本吸附剂的作用机理及其实用性 ,仍需要做大量的室内和现场工作。 相似文献
52.
闽江口水动力和污染扩散数值模拟 总被引:3,自引:0,他引:3
本文建立了闽江口二维水动力、污染扩散数值模型,模型采用ADI双向隐式求解。在水动力模拟中,对岸界的丁坝有用线性边界进行拟合,并考虑到河口区侧向摩擦作用;在污染扩散模拟中,用动态拟合的方法对浓度水边界进行了较为合理的改进。计算结果表明,本模型是成功的。 相似文献
53.
Water Quality in the Great Barrier Reef World Heritage Area: Past Perspectives, Current Issues and New Research Directions 总被引:3,自引:0,他引:3
Elevated sediment and nutrient concentrations have long been regarded as the pre-eminent water quality threats to the Great Barrier Reef, with the potential risk posed by other pollutants such as heavy metals, persistent chlorohydrocarbons, PCBs and petroleum related compounds considered to be of lesser consequence. However, the management focus on these latter types of pollutants has recently shifted to acknowledge the potential impact posed by diuron, dioxins, dieldrin, and mercury and cadmium concentrations detected in sediments and biota along the Great Barrier Reef and southern Queensland coastline. In general, these threats originate from areas dominated by intensive cropping agriculture and are exacerbated by high rainfall and erosion rates in the wet tropics region of the Queensland coast. Maintenance of long-term monitoring programmes, which utilize innovative data acquisition techniques will enable assessment of change in environmentally relevant pollutant concentrations over time. However, improved land management practices, which include an immediate minimization of vegetation clearance and responsible use of pesticides and fertilizers in Queensland are essential if water quality in the Great Barrier Reef World Heritage Area is to be maintained and protected. 相似文献
54.
To facilitate precise and cost-effective watershed management, a simple yet spatially and temporally distributed hydrological model (DHM-WM) was developed. The DHM-WM is based on the Mishra-Singh version of the curve number method, with several modifications: The spatial distribution of soil moisture was considered in moisture updating; the travel time of surface runoff was calculated on a grid cell basis for routing; a simple tile flow module was included as an option. The DHM-WM was tested on a tile-drained agricultural watershed in Indiana, USA. The model with the tile flow module performed well in the study area, providing a balanced water budget and reasonable flow partitioning. The daily coefficient of determination and Nash-Sutcliffe coefficient were 0.58 and 0.56, for the calibration period, and 0.63 and 0.62 for the validation period. The DHM-WM also provides detailed information about the source areas of flow components, the travel time and pathways of surface runoff.
EDITOR A. Castellarin; ASSOCIATE EDITOR F.-J. Chang 相似文献
55.
56.
The Zhujiang (Pearl) River Delta is the rapid economic development region in China since the opening and reform door policy
was carried out in 1978. Being the rapid development of industry and city, the impact on the aquatic environmental quality
was significant. The pollution caused the water quality descended and the ecological system degraded, and also impeded the
economic development. The characteristics and problems of the aquatic environment are: the capacity of aquatic environment
is large but hasn’t been utilized rationally, the water quality is influenced by saline sea water and tide current, the main
pollutants are organic matter and the pollution is going heavier, the concentration of pollutants change seasonally. The countermeasures
of aquatic environmental protection are: carrying out the environmental functional regionalization and controlling the total
amount of pollutant discharge, revising the industrial structure and making a rational industrial arrangement, raising the
rate of waste water treatment and making a full assessment of the water conservancy project. 相似文献
57.
DRASTIC has drawbacks in groundwater risk assessment that are important in guiding activities to prevention agricultural diffuse groundwater pollution. This paper presents an improved and GIS‐based D‐DRASTIC approach for groundwater nitrate risk assessment from diffuse agricultural sources based on DRASTIC. D‐DRASTIC considers the risk concept, nitrate loading, pollutant transport with runoff, depth to water, net recharge, aquifer media, soil media, topography, impact of the vadose zone media, and the hydraulic conductivity of the aquifer. D‐DRASTIC was developed within an ArcGIS environment and applied to the Upper Bann Catchment, Northern Ireland as a case study. D‐DRASTIC shows that ‘very high’ and ‘high’ zones of groundwater nitrate risk occupy 5% and 11% of the case study area, respectively. When considering groundwater pollution sources and pathways, the results using D‐DRASTIC are helpful in guiding the activities of groundwater pollution prevention at the catchment scale in the context of better implementation of the EU Water Framework Directive. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
58.
针对陕北地区油藏类型的特殊性,依据容积法计算模型,对控制储量计算中确定含油面积时的扩边问题进行了讨论,并提出了新的认识. 相似文献
59.
Distribution and sources of organochlorine pesticides in water and sediments from Daliao River estuary of Liaodong Bay,Bohai Sea (China) 总被引:1,自引:0,他引:1
The levels of 19 kinds of organochlorine pesticides (OCPs) in the aqueous phase, suspended particulate matter (SPM), pore water and sediments from Daliao River estuary of Liaodong Bay (Bohai Sea) in northeast China were investigated to evaluate their potential pollution risks. The total OCPs concentrations in the aqueous phase, SPM, pore water and sediments were 3.7–30.1 ng l−1, 4.6–52.6 ng l−1, 157–830 ng l−1 and 2.1–21.3 ng g−1 dry weight, respectively. The concentrations of OCPs, in the Daliao River estuary, are in the mid-range, as compared to those reported in other estuaries worldwide. The distribution of HCHs and DDTs were different indicating different contamination sources. Lindane is the main type of HCH and continuing use in northeast China of ‘pure’ HCH (lindane) rather than technical HCH accounts for the source. The ratios of (DDE + DDD)/DDT in the samples indicate no recent inputs of these chemicals to the estuary. 相似文献
60.
海南岛位于我国最南端,地下潜水有松散岩类孔隙潜水、火山岩类裂隙孔洞水、碳酸盐岩类裂隙溶洞水和基岩裂隙水四种基本类型。采用DRASTIC评价方法,对区内地下潜水的污染状况进行了调查评价,并将其防污性能划分为4个等级区:防污性能较好、防污性能中等、防污性能一般、防污性能较差。提出了在定区域内禁止一切不能引起地下水污染的活动,消灭污染源等措施。 相似文献