共查询到20条相似文献，搜索用时 15 毫秒
1.
Anne J. Pedersen Iben V. Kristensen Lisbeth M. Ottosen Alexandra B. Ribeiro Arne Villumsen 《Engineering Geology》2005,77(3-4):331-338
When chromated copper arsenate (CCA)-treated wood is removed from service and turns into waste, the contents of Cu, Cr and As remain high due to the strong fixation of CCA in the wood. This high content of toxic compounds presents a disposal challenge. Incineration of CCA-treated waste wood is not allowed in Denmark; instead, the wood is to be land-filled until new methods for handling the wood are available. Since the amounts of CCA-treated wood being removed from service is expected to increase in the years to come, the need for finding alternative handling methods is very relevant. In this study, the usefulness of Electrodialytic Remediation was demonstrated for handling of CCA-treated waste wood in pilot scale. The electrodialytic remediation method, which uses a low-level direct current (DC) as the cleaning agent, combines electrokinetic movement of ions in the wood matrix with the principles of electrodialysis. It has previously been shown that it is possible to remove Cu, Cr and As from CCA-treated wood using electrodialytic remediation in laboratory scale, but until now, the method had not been studied in large scale. The pilot-scale plant used in this study was designed to contain up to 2 m3 wood chips. Six remediation experiments were carried out. In these experiments, the process was up-scaled stepwise by increasing the distance between the electrodes from initially 60 cm to finally 150 cm. The remediation time was varied between 11 and 21 days, and phosphoric acid and/or oxalic acid was used to facilitate the desorption of CCA from the wood. In the most successful of the experiments carried out, the concentration of CCA in the wood was reduced by up to 82% for Cr, 88% for Cu and at least 96% for As. 相似文献
2.
为了研究一种高效的多种重金属污染土壤修复剂,本文采用了一种具有OH-缓释功能的改性Mg（OH）2,通过重金属污染土壤稳定化修复实验,探讨了改性Mg（OH）2对污染土壤中多种重金属（Pb、Cd、Cu、Zn）的稳定效率及对多种重金属形态分布的影响。结果表明,投加改性Mg（OH）2对土壤中多种重金属均有稳定作用,对Pb、Cd、Cu、Zn的稳定效率分别为72.42%、34.53%、87.64%和97.65%,且改性Mg（OH）2的投加使重金属交换态质量明显减少、残渣态质量增加,进一步提高了重金属的稳定性,降低了重金属生物有效性;另外,改性Mg（OH）2具有OH-缓释性,可使土壤长期保持一定的碱性,是一种经济有效的土壤修复剂。 相似文献
3.
Use of a resistivity cone for detecting contaminated soil layers 总被引：11，自引：0，他引：11
A cone-penetration technique was developed to detect contaminated soil layers with electrolytes and NAPLs. In this study, laboratory and field experiments were performed to apply the technique. In the laboratory, the change in resistivity was quantitatively examined by adding salt or oil to soil samples. The results showed that the resistivity measurement was varied with an order of ppm for the electrolyte concentration in soil. It was found that the resistivity of sand increased with increasing oil concentration. The effect of oil content was stronger for lower water content of sand.
The results obtained from field experiments showed that the resistivity cone can be used for detecting the contaminated layer in soils whose background values are known. Particularly, the instrument can be used effectively for examining the effects of remediation, by measuring the resistivity of the ground before and after remediation, unless the soil fabric changes significantly during remediation procedures. 相似文献
4.
为了揭示季节性低温胁迫下陇东黄土高原油污土壤环境因子对耐冷混合菌场地生态修复的响应机制,利用自主筛选构建的耐冷石油降解混合菌在甘肃省庆阳市庆城县马岭镇长庆油田陇东油泥处理站开展了为期7个月的场地修复实验,采用常规方法测定了不同季节土壤理化特性、酶活性和微生物群落特性等环境指标。结果表明：（1）在季节性低温胁迫下（9-11月）M2组（耐冷混合菌处理组）月平均降解率明显增加（P<0.01）,JZJ+M1组（金盏菊联合常温混合菌处理组）和M2组累计TPH降解率分别为15.37%±3.51%和28.64%±4.12%。（2）M2组土壤脱氢酶和多酚氧化酶在低温季节（LT）活性最高,且温度和处理存在显著交互作用（P<0.01）。在土壤营养元素方面,无论何种处理方式（JZJ+M1和M2）二者含量均为RT（常温季节）高于LT（P<0.05）,同时明显高于CK组（P<0.05）。（3）M2组土壤微生物群落Shannon-Wiener指数和均匀度指数在LT高于RT（P<0.05）。（4）NMDS和Pearson相关性分析结果显示,M2组在低温季节具有较高TPH降解率主要与土壤多酚氧化酶、脱氢酶、单月TPH降解率（μ2）和Shannon-Wiener指数有关,且均呈极显著正相关关系。通过分析环境因子的季节响应,优化场地修复在低温环境的降解条件、加速低温期石油烃降解速率,以期为陇东地区低温耐冷混合菌场地生态修复技术的推广应用提供参考和基础数据资料。 相似文献
5.
传统原位化学氧化地下水修复技术存在氧化剂迁移距离短和利用率低等问题。本研究在双井循环模式促进传质的基础上,通过注水井中的地下水电解原位提供O2和H2,配合乙二胺四乙酸(ethylenediamine tetraacetic acid,EDTA)络合溶解出含水层Fe(Ⅱ),活化O2产生羟基自由基(•OH),实现地下水三氯乙烯(TCE)的氧化降解。在填充了砂土和黏土互层的二维砂槽中,设置电流为0.2 A、流速为72 cm/d、初始TCE浓度为3 mg/L,经过9 d的连续通电处理后,TCE浓度降低到1 mg/L,降解率达到67%。通电前投加0.5 mmol/L EDTA,经过1 d水流循环后含水层中溶解态Fe(Ⅱ)浓度从02 mg/L增加到414 mg/L,黏土区域较高。通电过程中,循环井促进O2、Fe(Ⅱ)-EDTA和TCE的有效接触与反应,使TCE氧化降解。通电初期,黏土区域Fe(Ⅱ)氧化速率、TCE降解速率较周围慢,后期差异逐渐减小。未通电时加入醋酸钠可促进Fe(Ⅲ)还原,使含水层中铁循环利用。该修复过程通过循环井提升了氧化剂迁移距离,使用源于含水层的Fe(Ⅱ)-EDTA和稳定性较好的O2提高了氧化剂利用率,有望应用于有机污染地下水修复。 相似文献
6.
A. Arjoon A. O. Olaniran B. Pillay 《International Journal of Environmental Science and Technology》2013,10(2):395-412
Chlorinated hydrocarbons can cause serious environmental and human health problems as a result of their bioaccumulation, persistence and toxicity. Improper disposal practices or accidental spills of these compounds have made them common contaminants of soil and groundwater. Bioremediation is a promising technology for remediation of sites contaminated with chlorinated hydrocarbons. However, sites co-contaminated with heavy metal pollutants can be a problem since heavy metals can adversely affect potentially important biodegradation processes of the microorganisms. These effects include extended acclimation periods, reduced biodegradation rates, and failure of target compound biodegradation. Remediation of sites co-contaminated with chlorinated organic compounds and toxic metals is challenging, as the two components often must be treated differently. Recent approaches to increasing biodegradation of organic compounds in the presence of heavy metals include the use of dual bioaugmentation; involving the utilization of heavy metal-resistant bacteria in conjunction with an organic-degrading bacterium. The use of zero-valent irons as a novel reductant, cyclodextrin as a complexing agent, renewable agricultural biosorbents as adsorbents, biosurfactants that act as chelators of the co-contaminants and phytoremediation approaches that utilize plants for the remediation of organic and inorganic compounds have also been reported. This review provides an overview of the problems associated with co-contamination of sites with chlorinated organics and heavy metals, the current strategies being employed to remediate such sites and the challenges involved. 相似文献
7.
M. Khamforoush M.-J. Bijan-Manesh T. Hatami 《International Journal of Environmental Science and Technology》2013,10(3):533-544
The main scope of this work is applying an aerobic composting model for remediation of petroleum hydrocarbon-contaminated soil. For this purpose, the reaction kinetics was integrated with the mass and energy balances over the composting system. Literature pilot scale data for bioremediation of diesel oil-contaminated soil was used for model validation. Comparisons of simulation results with experimental data for diesel concentration and oxygen concentration showed good agreement during the remediation process. With validated model for bioremediation of diesel oil-contaminated soil, the influence of amendment type, bulking agent, amendment/soil ratio, bulking agent/soil ratio, moisture content and airflow rate were investigated on diesel biodegradation. The simulation results showed that maximum degradation of diesel occurred in the presence of yard waste as amendment. Furthermore, addition of bulking agent (wood chips) increased the diesel degradation about 6 %. In presence of yard waste as amendment and wood chips as bulking agent, the optimal values for maximum remediation were amendment/soil ratio (2.5 kg kg?1), bulking agent/soil ratio (2.25 kg kg?1), initial moisture content (62.5 %) and airflow (0.520 m3 day?1 kgBVS?1). 相似文献
8.
Electrokinetic remediation of an electroplating site: design and scale-up for an in-situ application in the unsaturated zone 总被引：1，自引：0，他引：1
In-situ electrokinetic remediation of contaminated soils requires integrated approaches and adequately engineered setups to control relevant mass fluxes. Based on laboratory findings, this study presents the design of a pilot-scale remediation at an operating electroplating site. The fine-textured soil developed from Jurassic limestone exhibits a chromium, copper, nickel, and zinc contamination down to depths of more than 4 m. The feasibility of an electrokinetic remediation in the unsaturated zone was tested in a lab-scale experiment with subsoil material sampled at the site. The electrodes were placed in water-impermeable, ion-selective membrane wells. This construction allows the necessary watering of the electrodes, maintains unsaturated conditions in the soil compartment, and enables the transfer of contaminant ions into the wells. In addition, the soil is protected from pH changes caused by water electrolysis at the electrodes. The setup includes a watering and drainage system to compensate the electroosmotic water flux and impede desiccation of the anodic region. With a direct current of 70 V and an electric field strength of 2.2 V cm−1, contaminant removal rates amounted up to 27% and 66% (w/w) of the initial zinc/copper and chromium/nickel concentrations. Copper, nickel, and zinc accumulated in the cathode well, while chromate species were enriched in the anode well. Given the successful lab-scale remediation, the pilot plant was designed for the in-situ treatment of a soil volume of 12 m3 below a production hall. A power of 500 V DC at a maximum current of 30 A is supplied by a transformer rectifier. This yields an electric field strength comparable to the lab-scale experiment and thereby similar contaminant transport velocities. A vacuum distillation unit is employed for process water reuse and to control electrolyte conductivity. To cope with chlorine gas generation at the anodes a gas absorber unit is employed. According to the lab-scale results, about 2, 9, 9, and 15 kg zinc, chromium, copper, and nickel, respectively, are expected to be removed from the field plot during an operation time of 10 months. 相似文献
9.
多环芳烃(PAHs)是一类具有致癌、致突变、致畸的碳氢化合物,具有较高的辛醇-水分配系数,易被土壤颗粒吸附而影响环境和人体健康。过硫酸钠(Na2S2O8)氧化法是近些年来国内外修复PAHs污染土壤较为常用的方法,但现阶段在测定修复后土壤中PAHs含量、进行土壤修复效果评估时亟待解决的问题是：经该方法修复的土壤,若土壤中残留有过硫酸钠,在样品前处理过程中由于提取温度较高,可能会进一步加速多环芳烃的氧化反应,从而影响土壤中PAHs的准确测定。本文建立了一种在修复后土壤中加入还原剂抗坏血酸,与残留的过硫酸钠反应生成脱氢抗坏血酸,采用索氏提取结合气相色谱-质谱法(GC-MS)同时测定土壤中16种PAHs的方法,PAHs加标回收率为76.2%～110.0%。而修复后土壤若不加还原剂直接进行索氏提取,用GC-MS测定,可能会使部分PAHs及替代物的测定不准确,PAHs加标回收率仅为6.0%～72.4%。通过对比分析表明,在样品提取前加入还原剂,可以有效地消除残留过硫酸钠的影响,提高测定修复后土壤中PAHs含量的准确性。 相似文献
10.
This paper reviews the use of Greek industrial minerals into developing low-cost, high-tech solutions to remediate parts of the chemical pollution environmental problem. The remediation strategy, based on the application and implementation of the Greek industrial minerals potential, became a major line of investigation in projects to develop new environmental technologies. Although past and current experiments have been successful on a lab scale in a number of applications, the results have not always been implemented on industrial scales. Greek olivine has been successfully tested as neutralizing agent for acid wastes, co-producing exploitable amounts of silica gel, magnesium sulphate and magnetite. Vermiculite is currently tested as an environmental ‘cleanser' in a variety of applications, i.e. metalliferous mine seepage and processing waters, organically contaminated waste water from the textile/dye industry and absorption material for oil spills. Wollastonite will be applied as long-term fertiliser and dolomite, as a substitute of asbestos in brake linings, as pollution controller of heavy metal concentrations in waste waters and as a binder to stabilize waste solids. Magnesite has been successfully applied for neutralization of acid mine wastes produced from active sulphide deposits. Zeolites (fly ash and perlite converted to zeolites were also considered) is an objective for several environmental applications, i.e. as floating absorbent for waste water ponds, as drinking water purificator or as smell abatement. 相似文献
11.
生物炭对土壤理化性质影响的研究进展简 总被引：10，自引：0，他引：10
Biochar is an organic material with high carbon content, most aromatic structure and great stability resulting from high temperature thermal conversion (usually < 700 ℃) of organic materials under the completely or in part anoxic condition. Due to its stable chemical properties, biochar has received widely attention as a strategy to reduce greenhouse gas emissions. In addition, biochar shows great potential in soil improvement and environmental pollution remediation, and provides a comprehensive solution for the global climate change, food crisis and ecological pollution remediation. Biochar is a carbon rich material, in association with porous characteristics and high surface area which are favorable to accumulating soil moisture, to increasing the porosity, to reducing density and bulk density, and to promoting the formation of soil aggregation. All the above soil physical improvement can provide a good environment for the growth of plants. Furthermore, biochar is an ideal acidic soil amendment which can improve the pH of acidic soil. It contains nutrient element which can be directly released into soil, and its surface charge and functional groups are conducive to soil nutrient retention, such as the reduced leaching of NH+4 and NO-3, PO3-4, therefore improve the efficiency of nutrient elements. However, the effect of biochar amendments highly influenced by raw materials and pyrolysis conditions is of inconsistent and sometimes even contrast results can be concluded. In this paper, we summarize the current status and knowledge gaps about the effect of biochar amendments on soil physical and chemical properties and some suggestions are also strengthened. Finally, some possible negative impacts of biochar application and research suggestions are discussed in order to better use of biochar in agriculture. 相似文献
12.
重金属污染土壤的修复一直是国内外环境研究者关注的重点环境问题之一.近年来,纳米材料在土壤重金属污染修复中的应用也受到了越来越多的关注.综述了主要纳米材料及其改性材料修复土壤重金属的应用、纳米材料的组合技术应用以及影响纳米材料修复土壤重金属效果的主要因素,提出了今后该领域应重点加强研发新的纳米材料,同时提高其在土壤中的扩散能力,研究从室内实验到田间实验的应用;进一步深入探讨了纳米材料在土壤中的环境行为及相关机理等,以期充分理解并进一步推动纳米材料在土壤重金属污染修复中的应用. 相似文献
13.
选取土壤、水系沉积物、岩石、超基性岩、黏土等标准物质,应用混合溶剂与样品质量比为14：1的高稀释比方法熔融制备测试样品,拟合校准曲线,建立X射线荧光光谱（XRF）同时测定硅酸盐岩石样品中18种组分（SiO2、Al2O3、TFe2O3、MgO、CaO、K2O、Na2O、TiO2、BaO、MnO、P2O5、Cr2O3、V2O5、Rb、Sr、Zr、Cu、Ni）的快速分析方法.应用帕纳科Eagon2全自动高频电感熔样机,称取7.0000 g（45Li2B4O7+10LiBO2+5LiF）混合溶剂与0.5000 g样品混合均匀,分别加入氧化剂饱和硝酸铵溶液2滴,脱模剂饱和溴化锂溶液4滴,于700℃先预氧化4 min,再1 120℃熔融9 min制备样片,自然冷却至室温.此熔样方法能保证样品中待测组分熔化完全,并制得表面光滑平整的样片.用国家标准物质验证,测试结果的准确度和精密度均符合《地质矿产实验室测试质量管理规范》（DZ/T 0130-2006）要求. 相似文献
14.
15.
微生物修复石油污染地下水的实验研究 总被引：6，自引：0，他引：6
为修复陕北黄土区石油污染地下水,采用优化土著微生物菌群的生物技术,进行了地下水中石油的降解与修复实验研究。在实验装置内加入了1.5%的优化菌群制剂,优化出的菌群初步鉴定主要有:假单胞菌属、微球菌属、放线菌属、真菌类的青霉属和曲霉属等。实验结果显示,在实验装置中人为添加石油含量为182.5 mg/l、862.5 mg/l、1695.0 mg/l时,经过28~37 d的微生物修复,地下水中石油的降解率为27.47%~92.46%,而无菌对照中的石油含量变化在5%以内,说明在无菌条件下地下水中石油降解缓慢。该实验过程验证了微生物修复技术在地下水石油污染修复中的有效性,探索了应用的可行性。 相似文献
16.
城市生活垃圾中重金属Cd污染修复是我国亟待解决的环境问题之一。为了确定最佳Cd污染修复技术,探究了多种镉修复技术在河道治理中的适用性。以华东地区城市河道疏浚底泥堆土修复工程为例,对重金属镉污染土壤的修复工艺进行了对比和分析。拟选定土壤稳定化修复技术、土壤淋洗技术和植物修复技术三种修复工艺对受污染土壤进行治理。实验结果表明,稳定化修复技术可以使土壤中镉的浸出率从33.3%降低到14.3%,能有效降低其在环境中的生物毒性,但镉的总量并不会降低;采用柠檬酸和草酸的土壤淋洗技术,能够使镉的去除率达到90.1%和92.4%;相比而言,植物修复技术具有更为突出的高效性、易操作和二次污染少的特点,但修复周期较长。从技术、经济、环境安全等多方面出发,分别对三种修复工艺进行了分析讨论,综合考虑了研究场地的现状和未来规划,最终确定土壤淋洗技术为治理河道底泥堆土镉污染的最佳选择。 相似文献
17.
凹凸棒石用于修复铜锌镉重金属污染土壤的研究 总被引：8，自引：1，他引：8
利用凹凸棒石黏土矿物优异的物化性能对采集的安徽铜陵地区重金属污染土壤进行盆栽修复试验,以降低种植蔬菜中重金属污染物的有效态含量。凹凸棒石与矿区土壤的质量配比设置5组(1∶10、1∶20、1∶40、1∶100以及原土),选择适宜在北京生长的四季小白菜和北京快菜进行种植,盆栽试验结果表明,使用凹凸棒石黏土矿物可以将土壤的pH值提高到5～8,改善了矿区的土壤环境条件,提高黏土矿物对重金属的吸附性能;通过适量添加凹凸棒石黏土矿物,对Cu元素的平均修复率达到31.50%,Zn元素的平均修复率达到26.15%,Cd元素的平均修复率达到34.92%,能够有效减少蔬菜对Cu、Zn、Cd三种重金属元素的吸收。凹凸棒石与土壤的质量比为1∶20时,对污染土壤的修复效果最佳。 相似文献
18.
Rhenium-Osmium (Re-Os) isotopic dating applied to the geochronology of hydrocarbon accumulation has been the forefront of international research in the last 10 years and has achieved significant achievements. However, our current researches are lacking in Re-Os isotopic chronology on the geochronology of hydrocarbon accumulation. The successful application of the Re-Os geochronology has enabled the determination of accurate and precise depositional ages for Organic-Rich Sedimentary rocks (ORS), the establishment of timing constraints of oil generation or migration, and the fingerprinting of the source of oil. On the basis of literatures study both at home and abroad, this article mainly dealt with the principle of Re-Os isotopic dating and analyzed the accumulation processes of Re and Os in a seawater-sediment system. Meanwhile, the test samples, sample preparation and analytical methodology of Re-Os isotopic dating were summarized. The results revealed that the initial 187Os/188Os ratio could constrain the age of oil generation or migration, and effectively evaluated the relationship between source rock and oil. The radiogenic 187Os/188Os ratio showed a positively correlated relationship with source rock age. This article proposed that hydrocarbon mature, biodegradation and water washing had minimal or no effect on data scatter about Re-Os isochron. However, the effects of postdepositional mobility of Re and Os, variations in the initial 187Os/188Os ratio, and thermochemical sulfate reduction could result in data scatter. The reproducibility and accuracy of Re-Os age was also closely related to the sample particle size and sample amount. Compared with other isotopic dating, the biggest advantage of Re-Os isotopic dating is to study geological body related to accumulation process, and to obtain direct evidence of hydrocarbon accumulation period. From what was discussed above, the article discussed the existing problems and put forward the future hot research and development direction of Re-Os isotope system, so as to promote the deep development of relative theory and technology of Re-Os isotopic dating. 相似文献
19.
Lisbeth M. Ottosen Anne J. Pedersen Alexandra B. Ribeiro Henrik K. Hansen 《Engineering Geology》2005,77(3-4):317-329
Numerous studies have been conducted with electrochemical removal of heavy metals from spiked kaolinite. Meanwhile, when moving from kaolinite to real soils, new factors must be taken into account—factors influencing, e.g., the buffering capacity of the soil against acidification and the adsorption/desorption processes of the heavy metals. The present study gives some examples where it is necessary to use an enhancement solution to aid desorption of Cu, Zn and Pb during electrodialytic treatment. Dependent on the composition of the pollution, different choices can be made. In the case of a Cu-polluted calcareous soil, ammonia may be used as enhancement solution, due to the formation of charged complexes between ammonia and Cu. Thus, Cu is mobile at high pH when ammonia is added and Cu can be removed without dissolving the calcareous parts. Zn is also mobilized by ammonia, but to a lesser extent than Cu. In the case of Cu, Zn and Pb at the same time, alkaline ammonium citrate may be a solution. It was shown that this enhancement solution could mobilize these three pollutants, but optimization of concentration and pH of the ammonium citrate is still needed. When choosing a remediation scheme for electrochemical treatment of an actual industrially polluted soil, this scheme must be chosen on basis of characterization of soil and pollution combination. 相似文献
20.
A geographic information system (GIS) raster technique has been developed and used interactively with remediation designers to evaluate the optimum extent of excavating soil contaminated by chlorinated solvents. The technique and the results of its application are presented. The site was a former chemical storage plant for acids and solvents. Two distinct solvent plumes were detected within the ground using a photo-ionisation detector. The solvents were found to be dissolved in the groundwater and migrating in the general direction of groundwater flow. A remediation strategy was proposed involving the localised excavation of contamination ‘hot spots’ followed by the implementation of a groundwater remediation system. A number of excavation options were discussed and the GIS raster technique was developed to evaluate these options in terms of contaminant removed and excavation cost.
The plumes were initially mapped using a triangular irregular network (TIN). These TIN models were rasterised to produce a regular grid of rectangular cells, each cell having a value relating to the concentration of contaminant at that spatial point. The proposed excavation zones were then overlaid on to the raster models as masks. The relationship between the value of contaminant concentration of cells within the mask (or excavation zone) and the total value of contaminant concentration of cells within the solvent plume was used to determine the efficiency of the excavation.
The excavation options were compared taking into account the percentage of the contaminant plume removed, the excavation area (soil volumes) and related costs. Once the GIS raster technique had been developed, it proved very quick to rerun the analysis for the other excavation zones. The optimum excavation zone, based upon cost and contaminant recovery, was found for the site. The technique helped by targeting the worst area of contamination and provided the client with a cost-benefit analysis of the different remediation options. 相似文献