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1.
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   

2.
以铁屑和纯Fe^0为供试介质处理地下水中Cr^6+,在不调节原水pH值情况下,通过室内对比试验发现铁屑比纯Fe^0的去除效率高,且可使处理后水中Cr^6+达到地下水质量标准的Ⅲ类标准,确定出铁屑去除Cr^6+的最佳运行参数:铁屑与Cr^6+的重量比为1395:1,反应时间为40 min,并分析讨论了其去除机理.  相似文献   

3.
木屑和花生壳吸附去除水溶液中Cr^3+的试验研究   总被引:20,自引:0,他引:20  
以废弃物木屑和花生壳作为吸附剂,进行了吸附去除水中Cr^3+的试验。研究了溶液pH值、初始Cr^3+浓度以及温度等因素对这2种吸附剂去除Cr^3+作用的影响,对吸附曲线作了线性拟合,确定了相应的平衡吸附率,在Cr^3+初始浓度为1、5、10和20mg/L时,木屑对Cr^3+的平衡吸附率为81%、68%、56%和40%,花生壳依次为77%、63%、53%和42%,并探讨了这2种吸附剂对溶液中Cr^3+的吸附机理。  相似文献   

4.
用羧甲基壳聚糖和膨润土制备复合吸附剂,研究了复合吸附剂在不同参数下对Cu^2+、Ni^2+和Cr^3+吸附的影响。结果表明,复合吸附剂对Ni^2+的吸附可以很快达到吸附平衡,而对Cu^2+和Cr^3+的吸附分别在30min和180min时达到平衡;且pH值对吸附容量的影响很显著。通过计算不同温度下的热力学参数△G、△H和△S,3种金属的△G〈0,证实这3种金属吸附都是自发过程。Cu^2+、Ni^2+和Cr^3+的吸附等温线较符合Langmuir型;反应动力学都更符合准二级吸附速率方程。  相似文献   

5.
钢渣预处理含铬废水及其废渣与铬渣的固化   总被引:6,自引:0,他引:6  
用钢渣对含铬废水进行预处理,探讨了钢渣粒度、用量、废水pH值和添加硫酸亚铁还原剂的影响。结果表明,经硫酸亚铁还原处理后再用钢渣处理比单纯用钢渣处理的效果明显提高,采用钢渣/总铬质量比为40的100目钢渣处理经硫酸亚铁还原后的含铬废水,总铬和Cr^6+去除率分别达79%和84%,采用钢渣柱进行的两级淋滤实验进一步表明该方法可作为工业上含铬废水处理的预处理段。处理后的废钢渣同工业铬渣一起进行水泥固化,标准养护20d后固化体表面Cr^6+浸出率、破碎至5mm粒径以下和酸雨淋溶下的浸出液Cr^6+浓度均符合安全标准,可作为普通建材或进行填埋处置。  相似文献   

6.
反应柱充填活性炭法处理轧钢含铬废水的研究   总被引:3,自引:0,他引:3  
吴克明  潘留明  黄羽 《环境污染与防治》2005,27(5):379-381,i0005
针对轧钢含铬废水,分别采用活性炭和离子交换树脂吸附处理的方法对其中的Cr^6+和Cr^3+的去除效果进行了系统的研究。静态试验考查了pH、吸附剂用量和搅拌速度等因素的影响,同时使用微型反应柱集成装置对穿透时间、吸附容量及活性炭再生方法进行了探讨,动态试验表明反应柱充填活性炭法能有效地处理含铬废水。  相似文献   

7.
膨润土对Pb^2+、Cu^2+、Cr^3+的吸附动力学及等温线研究   总被引:4,自引:0,他引:4  
研究所用膨润土的主要成分为SiO2和Al2O3,属于Ca基膨润土,BET表面积为50.83m^2/g。在恒温及恒定pH条件下,用静态吸附法研究了膨润土对Pb^2+、Cu^2+、Cr^3+的吸附特性,结果表明其较好地符合Lagergren二级吸附速率方程,对这3种离子的吸附速率为Pb^2+〉Cu^2+〉Cr^3+。利用3种等温线方程对吸附过程进行拟合,发现利用Langmuir吸附等温方程计算的值与膨润土吸附Pb^2+、Cu^2+、Cr^3+试验数据最为吻合。膨润土对3种金属离子的平衡吸附量为Cr^3+〉Cu^2+〉Pb^2+。  相似文献   

8.
利用芦竹修复重金属污染湿地的研究   总被引:4,自引:0,他引:4  
研究了芦竹(Arundo donax linn)对Cu^2+、Ni^2+、Cr^6+重金属污染湿地的响应和对该污染湿地的影响。实验结果表明,芦竹对这3种重金属离子有一定的耐受性,并有不同程度的吸收,Cu^2+、Ni^2+和Cr^6+去除率分别为63.8%,42.3%和34.4%。芦竹在100mg/kg浓度的Cu^2+、Ni^2+污染湿地中生长正常,在低浓度(55mg/kg)Cr^6+污染中能存活,但生长速度较慢。在100mg/kg浓度Cr^6+污染湿地中,出现急性中毒现象,半月后致死。在重金属污染环境中,芦竹普遍出现失绿现象,但除高浓度cr。’(100mg/kg)以外,都能正常存活,表现出较强的适应性。  相似文献   

9.
东京根霉对重金属Cr^3+、Mn^2+和Zn^2+的吸附研究   总被引:5,自引:0,他引:5  
利用固定化发酵中产生的废菌体——东京根霉(Rhizopustonkinesis)去除废水中Cr^3+、Mn^2+和Zn^2+,研究了预处理、pH、温度、金属离子初始浓度、吸附时间等条件对吸附量的影响。结果表明,用NaOH浸泡4—6h、在pH=5—6,温度25-35℃时吸附效果最好,用Langmuir、Freundlich和Temkin方程对其吸附等温线进行拟合,相关性都比较好;用不同的吸附动力学方程描述东京根霉吸附金属离子的最优和最次模型分别为Elovich方程和一级扩散方程,双常数方程和抛物线扩散方程拟合介于前二者之间。  相似文献   

10.
为评价厌氧消化污泥与菌渣对煤矸石特征污染物释放的原位控制效果,分别向煤矸石中添加厌氧消化污泥、菌渣、厌氧消化污泥与菌渣混合物,稳定、陈化30d后测定煤矸石浸出液pH、电导率(EC)、氧化还原电位(Eh)、总Fe、Fe~(2+)、SO_4~(2-)及煤矸石有效态Fe、Mn、Cu、Zn等指标进行控制效果研究。结果表明:(1)厌氧消化污泥、菌渣及其混合物的添加均能不同程度提高煤矸石浸出液pH。(2)厌氧消化污泥、菌渣及其混合物的添加均可不同程度降低煤矸石浸出液总Fe、Fe~(2+)、SO_4~(2-)及煤矸石有效态Fe,且厌氧消化污泥与菌渣混合组降低效果总体上最明显。(3)厌氧消化污泥、菌渣及其混合物对煤矸石中Mn、Zn、Cu释放的影响存在明显差别,其中厌氧消化污泥、厌氧消化污泥与菌渣混合组均增加煤矸石浸出液总Mn、总Zn及煤矸石有效态Mn、Zn;菌渣组、厌氧消化污泥与菌渣混合组均能有效降低煤矸石浸出液总Cu及煤矸石有效态Cu。  相似文献   

11.
We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.  相似文献   

12.
13.
Approximately 25, 000-35, 000 dry cleaning facilities currently operate in the U.S. The release of perchloroethylene and other solvents from these establishments represents a major source of soil and groundwater contamination. The manner in which dry cleaning solvents escape from dry cleaning plants is, for all practical purposes, identical for chlorinated and petroleum hydrocarbon solvents and is related to one of the following events: the catastrophic failure of a component of the dry cleaning system, the improper installation, operation or maintenance of the dry cleaning equipment or a combination of all of these causes. Acceptable customs, codes and regulations can also dictate what is authorized for operation of a dry cleaning facility in a particular community, geographic area during a particular time frame. Environmental litigation dealing with the origin of a solvent release from dry cleaners tends to focus on the design and manufacture of dry cleaning industry machines such as washers, washer extractors, tumblers, solvent filters, water separators, stills and spotting boards. A thorough analysis of the daily operations of dry cleaners often reveals that poor maintenance, failure to follow the manufacturer's instructions and the actions of the operator are the most likely causes of soil and groundwater pollution. In order to forensically evaluate the most probable origins of a solvent release and to examine issues regarding liability, a thorough understanding of the history of dry cleaning and a detailed analysis of the operation and maintenance of the dry cleaning equipment are necessary. The discovery of solvent plumes in the vicinity of dry cleaning plants may suggest that the solvent source is the dry cleaning plant; however, the presence of these plumes does not necessarily indicate that the dry cleaning equipment was defectively designed or manufactured. A thorough review of the type of equipment used over the life of the dry cleaning plant and verifiable solvent mileage records frequently indicates that operators of the plant have disposed of solvent and contaminated solids into the municipal sewer or on ground surfaces.  相似文献   

14.
Abstract

The purpose of this study was to determine radionuclide and trace element concentrations in bottom‐feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for 3H, 90Sr, 137Cs, totU, 238Pu, 239,240Pu, and 241Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of 90Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p<0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium‐90 in fish muscle plus bone tissue significantly (p<0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E‐02 pCi g‐1 [126E‐02 Bq kg‐1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E‐02 pCi g‐1 [518E‐02 Bq kg‐1]). The differences in 90Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (±2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 ± 0.1 mrem y‐1 (1.0 ± 1.0 μSv y‐1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y‐1 (1000 μSv y‐1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p<0.05) concentrations than in muscle of fish collected from background locations.  相似文献   

15.
The effect of malathion [diethyl(dimethoxythiophosphorylthio)succinate] at sublethal concentration (0.006 ppm) on intestinal parameters of cricket frog (Fejervarya limnocharis) was studied for 24 hrs to 240 hrs of exposure and remarkable histopathological alterations were observed. The study on intestinal parameters revealed acute pathological conditions in the intestinal wall. The toxic effect became evident as the cytoplasm of the cells disintegrated and the cells became empty and vacuolated. The cell membranes were also ruptured. Degenerative changes of the absorptive surface (villi) of the intestine in the different periods of exposure were pronounced. Severe atrophic nature (necrotic mucosa) of the intestine began from 48 hrs onwards to 96 hrs of exposure.  相似文献   

16.
Abstract

This paper summarizes radionuclide concentrations (3H, 90Sr, 137Cs, 238Pu, 239,240Pu, 241Am, and totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y‐1 (2.2 μSv y‐1), deer bone = 3.8 mrem y‐1 (38 μSv y‐1), elk muscle = 0.12 mrem y‐1 (1.2 μSv y‐1), and elk bone = 1.7 mrem y‐1 (17 μSv y‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y‐1 (1000 μSv y‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.  相似文献   

17.
The role of nitrogen (N) in acidification of soil and water has become relatively more important as the deposition of sulphur has decreased. Starting in 1991, we have conducted a whole-catchment experiment with N addition at Gårdsjön, Sweden, to investigate the risk of N saturation. We have added 41 kg N ha−1 yr−1 as NH4NO3 to the ambient 9 kg N ha−1 yr−1 in fortnightly doses by means of sprinkling system. The fraction of input N lost to runoff has increased from 0% to 10%. Increased concentrations of NO3 in runoff partially offset the decreasing concentrations of SO4 and slowed ecosystem recovery from acid deposition. From 1990-2002, about 5% of the total N input went to runoff, 44% to biomass, and the remaining 51% to soil. The soil N pool increased by 5%. N deposition enhanced carbon (C) sequestration at a mean C/N ratio of 42-59 g g−1.  相似文献   

18.
This study aimed to evaluate the leaching of pesticides and the applicability of the Attenuation Factor (AF) Model to predict their leaching. The leaching of carbofuran, carbendazim, diuron, metolachlor, α and β endosulfan and chlorpyrifos was studied in an Oxisol using a field experiment lysimeter located in Dom Aquino – Mato Grosso. The samples of percolated water were collected by rain event and analyzed. Chemical and physical soil attributes were determined before pesticide application to the plots. The results showed that carbofuran was the pesticide that presented a higher leaching rate in the studied soil, so was the one representing the highest contamination potential. From the total carbofuran applied in the soil surface, around 6 % leached below 50 cm. The other pesticides showed lower mobility in the studied soil. The calculated values to AF were 7.06E-12 (carbendazim), 5.08E-03 (carbofuran), 3.12E-17 (diuron), 6.66E-345 (α-endosulfan), 1.47E-162 (β-endosulfan), 1.50E-06 (metolachlor), 3.51E-155 (chlorpyrifos). AF Model was useful to classify the pesticides' potential for contamination; however, that model underestimated pesticide leaching.  相似文献   

19.
Endosulfan in China 2—emissions and residues   总被引:4,自引:0,他引:4  
Background, aim, and scope  Endosulfan is one of the organochlorine pesticides (OCPs) and also a candidate to be included in a group of new persistent organic pollutants (UNEP 2007). The first national endosulfan usage inventories in China with 1/4° longitude by 1/6° latitude resolution has been reported in an accompanying paper. In the second part of the paper, we compiled the gridded historical emissions and soil residues of endosulfan in China from the usage inventories. Based on the residue/emission data, gridded concentrations of endosulfan in Chinese soil and air have been calculated. These inventories will provide valuable data for the further study of endosulfan. Methods  Emission and residue of endosulfan were calculated from endosulfan usage by using a simplified gridded pesticide emission and residue model—SGPERM, which is an integrated modeling system combining mathematical model, database management system, and geographic information system. By using the emission and residue inventories, annual air and soil concentrations of endosulfan in each cell were determined. Results and discussion  Historical gridded emission and residue inventories of α- and β-endosulfan in agricultural soil in China with 1/4° longitude by 1/6° latitude resolution have been created. Total emissions were around 10,800 t, with α-endosulfan at 7,400 t and β-endosulfan at 3,400 t from 1994 to 2004. The highest residues were 140 t for α-endosulfan and 390 t for β-endosulfan, and the lowest residues were 0.7 t for α-endosulfan and 170 t for β-endosulfan in 2004 in Chinese agricultural soil where endosulfan was applied. Based on the emission and residue inventories, concentrations of α- and β-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell. We have estimated annual averaged air concentrations and the annual minimum and maximum soil concentrations across China. The real concentrations will be different from season to season. Although our model does not consider the transport of the insecticide in the atmosphere, which could be very important in some areas during some special time, the estimated concentrations of endosulfan in Chinese air and soil derived from the endosulfan emission and residue inventories are in general consistent with the published monitoring data. Conclusions  To our knowledge, this work is the first inventory of this kind for endosulfan published on a national scale. Concentrations of the chemical in Chinese air and agricultural surface soil were calculated for each grid cell. Results show that the estimated concentrations of endosulfan in Chinese air and soil agree reasonably well with the monitoring data in general. Recommendations and perspectives  The gridded endosulfan emission/residue inventories and also the air and soil concentration inventories created in this study will be updated upon availability of new information, including usage and monitoring data. The establishment of these inventories for the OCP is important for both scientific communities and policy makers.  相似文献   

20.
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