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671.
利用固相微萃取、微波萃取与液相色谱联用方法,对滴水湖水系环境中的水样、沉积物和生物样品中16种美国环境保护局优控的多环芳烃(PAHs)进行检测。结果表明,滴水湖水系水体中16种PAHs总量(∑PAHs)为19~446 ng·L~(-1),沉积物中为90~1 410 ng·g~(-1)dw(干重),生物体内为73~426 ng·g~(-1)dw;水中PAHs以2~3环为主,沉积物和水生生物体内均以3~4环为主;与国内外其他水系相比,表层水体中PAHs的污染水平较低,沉积物整体处于低到中度污染水平,生物体处于中等污染水平;滴水湖水体中的贝类食用风险很低,食用过量鲻鱼可能存在潜在致癌风险。污染源分析表明,滴水湖水体环境中PAHs的来源复杂,且随着滴水湖旅游资源及自贸区的开发,游客和交通流量日益增加,游船石油泄漏以及交通石油和汽油的燃烧逐渐成为滴水湖水体环境中有机污染物的主要来源。  相似文献   
672.
Toxic metals accumulated in the human body are predominantly absorbed by the digestive tract in non-occupationally exposed populations. In the current study, we collected plowed soil samples, and investigated the varied food compositions in a mining and smelting area in southwestern China, to measure the concentrations of ten potentially toxic metals—As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sr, and Zn. We collected information on the daily intakes of these metals to assess the health risks associated with their exposure among children and adults. The urine concentrations of the metals were also measured to obtain data on the amounts present in the body. The results showed that the hazard indexes (HIs) of As, Ba, Cd, Cr, Ni, Pb, and Sr were all larger than 1, for both adults and children; the Zn and Cu values were comparatively higher in children. The intake of staple foods of the region posed the greatest health risk, while drinking water only posed risks clearly associated with As exposure. The urine samples of local residents contained larger amounts of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn, confirming the hazards in the health risk assessment. Obvious differences in the urine metal concentrations between men and women were confirmed. In conclusion, higher concentrations of metals in the surface soil and rain water were the predominant cause of elevated exposure through home-grown crops and produce to accumulate in local residents’ bodies.  相似文献   
673.
简述了新时期环境监测数据产品内涵,分析了当前数据产品在信息化程度、深度开发、数据质量和信息公开等方面存在的问题;提出,要不断提高数据产品的信息化水平,推进其深度开发,要立足于服务社会和管控需求,加强数据产品可追溯能力建设,针对现各部门存在的"数据孤岛"问题,增强各部门间监测数据的可比性,推进区域污染物排放、空气环境质量、水环境质量等信息公开,为政府决策提供准确的技术支持,为公众、企业提供优质服务。  相似文献   
674.
The presence of humic acid (HA) in water poses environmental problems because it enhances the transport of several contaminants. A series of column experiments was conducted toward studying HA transport in different porous media under various pH, ionic strength, and flow rate conditions. The results showed that decreasing pH and increasing ionic strength increased adsorption and therefore delayed the transport of HA in porous media. However, increasing flow rate accelerated the transport of HA in porous media. The effects of pH, ionic strength, and flow rate varied with the solid matrix and were more evident in sands of smaller average particle diameter than in those with larger ones. These factors must be considered when predicting the environmental fate of HA. The results also suggested that HA adsorption was an important process controlling HA transport and should be considered in studies of HA behavior in porous media.  相似文献   
675.
Soil erosion is a serious environmental problem in Guizhou Province, which is located in the centre of the karst areas of southwestern China. Unfortunately, Guizhou Province suffers from a lack of financial resources to research, monitor and model soil erosion at large watershed. In order to assess the soil erosion risk, soil erosion modeling at the watershed scale are urgently needed to be undertaken. This study integrated the Revised Universal Soil Loss Equation (RUSLE) with a Geographic Information System (GIS) to estimate soil loss and identify the risk erosion areas in the Maotiao River watershed, which is a typical rural watershed in Guizhou Province. All factors used in the RUSLE were calculated for the watershed using local data. It was classified into five categories ranging from minimal risk to extreme erosion risk depending on the calculated soil erosion amount. The soil erosion map was linked to land use, elevation and slope maps to explore the relationship between soil erosion and environmental factors and identify the areas of soil erosion risk. The results can be used to advice the local government in prioritizing the areas of immediate erosion mitigation. The integrated approach allows for relatively easy, fast, and cost-effective estimation of spatially distributed soil erosion. It thus indicates that RUSLE-GIS model is a useful and efficient tool for evaluating and mapping soil erosion risk at a large watershed scale in Guizhou Province.  相似文献   
676.
Water-borne pathogenic bacteria are always the top priority to be removed through disinfection process in water treatment due to their threat to human health. It was necessary to develop novel disinfection methods since the conventional chlorine disinfection was inefficient in inactivating chlorine-resistant bacteria, inducing the viable but non-culturable(VBNC) bacteria and forming disinfection by-products(DBPs). In this study, the inactivation of four model strains including Gram-negative(G  相似文献   
677.
To investigate nitrous acid(HONO) levels and potential HONO sources above crop rotation fields. The HONO fluxes were measured by the aerodynamic gradient(AG) method from 14 December 2019 to 2 January 2020 over an agricultural field in the Huaihe River Basin. The ambient HONO levels were measured at two different heights(0.15 and 1.5 m), showing a typical diurnal cycle with low daytime levels and high nighttime levels. The upward HONO fluxes were mostly observed during the day, whereas deposition...  相似文献   
678.
对鹤壁煤矿区第10矿煤矸石进行连续淋溶试验,模拟煤矸石矿井填充后对地下水环境的影响.测定pH值、电导率、F-、总硬度、Zn、Mn、Cr6 、Cd、Cu和Pb等项目,实验结果表明,煤矸石淋出液中F-和Cr6 超标,Mn接近标准,pH值偏高,对地下水环境存在一定影响.其他各元素含量甚微,多未检出.  相似文献   
679.
采用序半连续式反应器(sequencing fed-batch reactor,简称SFBR)对人工合成废水顺序地进行硝化和反硝化动力学进行了研究.硝化和反硝化所用微生物为活性污泥.反应器在不同的操作条件进行操作,获得了用于确定动力学常数的数据;获得动力学参数um=0.05 h-1,KNO=2.0 mg/L,y=0.47 mg X/mg N,a=0.001 h-1.类似地确定了反硝化动力学参数kD=0.01 h-1和KD,NO=0.4 mg/L.在一定范围内硝化和反硝化速率随着氨浓度和硝酸盐浓度的增加而增加.实验数据表明,硝化和反硝化的动力学符合Monod动力学方程.  相似文献   
680.
This study presents the field investigations into the effects of cover soils and leachate subsurface irrigation on N2O emissions from municipal solid waste landfills. Landfill Site A and Site B, covered with carefully chosen infertile soils, were selected to monitor their diurnal and seasonal variations of N2O emissions. The annual average N2O flux was 469 ± 796 μg N2O-N m−2 h−1 in Site B with leachate subsurface irrigation, three times that of Site A without leachate irrigation. When an additional soil containing lower contents of carbon and nitrogen was introduced to cover part of Site B, its N2O fluxes decreased by 1-2 orders of magnitude compared with the left area of Site B. This suggested that carefully selected cover soils could substantially reduce N2O emissions even under leachate subsurface irrigation. Statistical analysis proved that the availabilities of soil moisture and mineralized nitrogen were the key parameters controlling landfill N2O emissions.  相似文献   
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