Evaluation of electrochemical processes for the removal of several target aromatic hydrocarbons from petroleum contaminated water

Ground and surface water contamination resulting from the leakage of crude oil and refined petroleum products is a serious and growing environmental problem throughout the world. Consequently, a study of the use of electrochemical treatment in the clean-up was undertaken with the aim of reducing the water contamination by aromatic pollutants to more acceptable levels. In the experiments described, water contamination by refined petroleum products was simulated under laboratory conditions. Electrochemical treatment, using aluminium electrodes, has been optimised by full factorial design and surface response analysis in term of BTEX and PAHs removal and energy consumption. The optimal conditions of pH, current density, electrolysis time, electrolyte type, and electrolyte concentration have then been applied in the treatment of real water samples which were monitored as petroleum contaminated samples. Treatment results have shown that electrochemical methods could achieve the concentration of these pollutants to undetectable levels in particular groundwater and surface water, hence, they can be highly effective in the remediation of water contaminated by aromatic hydrocarbons, and the use of these processes is therefore recommended.     

铬渣污染场地修复技术研究进展

铬渣对中国地下水、地表水和土壤造成了严重污染,并对生态环境和人体健康构成了巨大威胁。开展对铬渣污染场地的修复工作已迫在眉睫。在分析铬污染特性的基础上,阐述了国内外最新铬污染场地修复技术研究动态,并概括分析了其不足与未来铬渣污染场地修复技术的发展趋势。     

Toxicity assessment for petroleum-contaminated soil using terrestrial invertebrates and plant bioassays

The assessment of soil quality after a chemical or oil spill and/or remediation effort may be measured by evaluating the toxicity of soil organisms. To enhance our understanding of the soil quality resulting from laboratory and oil field spill remediation, we assessed toxicity levels by using earthworms and springtails testing and plant growth experiments. Total petroleum hydrocarbons (TPH)-contaminated soil samples were collected from an oilfield in Sfax, Tunisia. Two types of bioassays were performed. The first assessed the toxicity of spiked crude oil (API gravity 32) in Organization for Economic Co-operation and Development artificial soil. The second evaluated the habitat function through the avoidance responses of earthworms and springtails and the ability of Avena sativa to grow in TPH-contaminated soils diluted with farmland soil. The EC₅₀ of petroleum-contaminated soil for earthworms was 644 mg of TPH/kg of soil at 14 days, with 67 % of the earthworms dying after 14 days when the TPH content reached 1,000 mg/kg. The average germination rate, calculated 8 days after sowing, varied between 64 and 74 % in low contaminated soils and less than 50 % in highly contaminated soils.     

Modelling vegetation greenness responses to climate variability in a Mediterranean terrestrial ecosystem

Accurate knowledge of the quality and environmental impact of the highway runoff in Pear River Delta, South China is required to assess this important non-point pollution source. This paper presents the quality characterization and environmental impact assessment of rainfall runoff from highways in urban and rural area of Guangzhou, the largest city of Pear River Delta over 1 year’s investigation. Multiple regression and Pearson correlation analysis were used to determine influence of the rainfall characteristics on water quality and correlations among the constituents in highway runoff. The results and analysis indicates that the runoff water is nearly neutral with low biodegradability. Oil and grease (O&G), suspended solids (SS) and heavy metals are the dominant pollutants in contrast to the low level of nutrient constituents in runoff. Quality of highway runoff at rural site is better than that of at urban site for most constituents. Depth and antecedent dry period are the main rainfall factors influencing quality of highway runoff. The correlation patterns among constituents in highway runoff at urban site are consistent with their dominant phases in water. Strong correlations (r ≥ 0.80) are found among chemical oxygen demand (COD), total phosphorus, Cu and Zn as well as conductivity, nitrate nitrogen and total nitrogen. O&G, COD, SS and Pb in highway runoff at urban site substantially exceed their concentrations in receiving water of Pear River. The soil directly discharged by highway runoff at rural site has contaminated seriously by heavy metals in surface layer accompanying with pH conversion from original acidic to alkaline at present.     

严格管控类耕地非食用植物镉修复效果评价

综述了国内外在烟草,树木(杨树、柳树、桑树),纤维植物(苎麻、棉花)和蓖麻等非食用植物修复土壤镉方面的研究与应用进展,综合分析其修复能力与经济效益,得出蓖麻和苎麻的修复效果最佳.针对严格管控类耕地土壤镉修复,提出了开展非食用植物修复大田试验示范、研发环境友好型辅助措施、优化种植结构调整生态补偿机制,以及及时开展耕地土壤环境质量类别动态调整等建议.     

基于综合环境风险的砷污染场地优控筛选方法

污染场地的优控筛选是国家和地区污染场地管理的关键环节,有利于提高污染场地修复的高效性和经济性。研究以污染源强、污染途径脆弱性和受体敏感性作为筛选的主要因素,构建了基于综合环境风险的优控重金属污染场地筛选方法。通过调查某市15个砷渣污染场地,利用综合环境风险指数法分析区域不同污染场地的危害程度,据此推算不同污染场地危害 程度大小次序,并设置不同情景进行敏感性分析,从而筛选出某市优控砷渣污染场地名单。结果表明:污染场地H15和H12在不同权重情景下均处于高危害程度水平,为优控污染场地；H2在多数情景下危害程度较高,确定为备选优控污染场地。     

Availability and Assessment of Fixing Additives for The in Situ Remediation of Heavy Metal Contaminated Soils: A Review

The use of low-cost and environmental safety amendments for the in situ immobilization of heavy metals has been investigated as a promising method for contaminated soil remediation. Natural materials and waste products from certain industries with high captive capacity of heavy metals can be obtained and employed. Reduction of extractable metal concentration and phytotoxicity could be evaluated and demonstrated by the feasibility of various amendments in fixing remediation. In this review, an extensive list of references has been compiled to provide a summary of information on a wide range of potentially amendment resources, including organic, inorganic and combined organic-inorganic materials. The assessment based on the economic efficiency and environmental risks brought forth the potential application values and future development directions of this method on solving the soil contamination.     

Assessment of metal contamination using X-ray fluorescence spectrometry and the toxicity characteristic leaching procedure (TCLP) during remediation of a waste disposal site in Antarctica

The remediation of the Thala Valley landfill, Casey Station, East Antarctica, is part of efforts to clean-up contaminated sites associated with the Australian Antarctic Program. These sites, ranging from abandoned rubbish dumps to fuel spills, are contaminated principally with metals and petroleum hydrocarbons. Remediation success depends on accurate, cost-effective and timely--fit-for-purpose--chemical analysis of soil and water samples from the site, which is required to guide excavation, the in situ or off-site treatment and disposal of contaminated material, and to validate satisfactory remediation. Owing to the remote location of Antarctica, it is necessary to carry out chemical analyses on-site. Waste and soil contaminated with Pb, Zn, Cd, and Cu were excavated from Thala Valley for removal to Australia, treatment and disposal. Analysis of total metal concentrations in soil was performed at Casey Station with a transportable energy dispersive X-ray fluorescence (EDXRF) spectrometer. Soil samples were prepared using a simple size-fractionation method to expedite sample throughput. A method for assessing contaminant mobility in solid waste (toxicity characteristic leaching procedure, TCLP) was also used to characterise soil. Although this was more labour-intensive and time-consuming than the total metals analysis, it was of great utility because leachable metals were often significant determinants in the assessment of contaminated soil. The combined data helped managers during remediation, directing excavation and allowing waste to be classified for treatment and disposal before its return to Australia.     

江苏省土壤修复产业发展现状及对策分析

简述了江苏省土壤修复市场发展情况及土壤修复技术发展现状。从营商环境、市场竞争力、标准法规建设等方面分析存在的市场问题,提出应规范市场环境、培育企业竞争力,加强标准制定、模式创新和人才培养的建议。针对场地环境调查与风险评估技术有待提升、地下水修复技术研发工作投入不足、修复后土壤监测和安全再利用问题突出等技术问题,提出,应完善环境调查与风险评估技术研究,加强土水修复材料、装备与工艺研发,提升长期监测及修复再利用研究的建议。以期为土壤修复行业的良性发展提供有益参考。     

我国场地调查土壤中污染物监测分析方法标准的思考

结合重点行业企业用地调查工作实践,分析了我国场地调查土壤中污染物监测分析方法标准现状和存在的问题,包括缺少一些行业特征污染物、重金属形态分析和现场快速检测技术标准,以及部分方法的可比性和适用性较差等,提出了结合污染场地环境调查土壤基质的特点及风险评估与治理修复的需求,加快制定缺失的行业特征污染物和重金属形态分析方法标准,及时修订和完善现行分析方法体系,增强标准的可比性、适用性和可操作性等建议.     

Heavy metal concentrations in groundwaters and soils of Thane Region of Maharashtra, India

Thane district is one of the most industrialized districts in Maharashtra. The heavy industrialization and the increasing urbanization are responsible for the rapidly increasing stress on the water and soil environment of the area. Therefore, an attempt has been made through comprehensive study on the groundwater contamination and soil contamination due to heavy metals in Thane region of Maharashtra. The area undertaken for the study was Thane and its suburbans Kalwa, Divajunction, Dombivali, Kalyan, and Ulhasnagar. Industrialization and urbanization lead to generation of large volumes of wastewater from domestic, commercial, industrial, and other sources, which discharged in to natural water bodies like river and creek in this region. Groundwater samples and soil samples were collected from residential, commercial, agriculture, and industrial areas. Groundwater samples were analyzed for various water quality parameters. The analytical data shows very high concentration of total dissolved solids, total hardness, total alkalinity, chemical oxygen demand, chloride etc. Groundwater and soil samples were analyzed for ten heavy metals by inductively coupled plasma (ICPE-9000) atomic emission spectroscopy. The analytical data reveal that, very high concentration level of arsenic, cadmium, mercury, and nickel throughout the industrial area. The random dumping of hazardous waste in the industrial area could be the main cause of the groundwater and soil contamination spreading by rainwater and wind. In the residential areas the local dumping is expected to be the main source for heavy metals. A comparison of the results of groundwater with WHO guidelines show that most of the groundwater sampling station are heavily contaminated with organic matter and heavy metals. Groundwater samples are heavily contaminated by arsenic, cadmium, mercury, and nickel. Similarly, the results of heavy metals in soil compared with Swedish soil guideline values for polluted soil show that soil samples collected from residential, commercial and industrial areas are heavily contaminated by arsenic, cadmium, mercury, and nickel.     

生态修复后某矿区下游农田土壤金属污染特征与风险评价

为研究广东省某矿区开展生态修复多年后下游农田土壤的金属污染状况，选取该矿区下游某村周边农田土壤及灌溉水渠作为研究对象，对该区域采集了40个土壤表层样本和8个水体样本，利用Arcgis软件对农田土壤样品中As、Cu、Cd、Pb、Zn、Mn和Fe₂O₃的质量分数进行克里金空间插值，解析该区域农田土壤金属的空间分布特征；采用综合污染指数法和潜在生态风险指数法对该区域耕作层土壤中As、Cu、Cd、Pb、Zn和Mn进行风险评价。结果表明，40个土壤样品中As、Cd、Cu、Zn和Pb的超标率分别为77.5%、70%、87.5%、27.5%和67.5%,说明调查区域农田土壤污染属于多金属复合污染，且对农作物的生产和安全产生巨大的威胁。部分土壤样品中As、Pb和Cd含量超过了中国农用地土壤污染风险管制值，需采取严格管控措施。通过分析土壤金属的空间分布，发现土壤金属含量超标点位主要位于灌溉口与受污染河流周边，且含量与离灌溉口距离成反比。结合目前灌溉水样中的金属均未超标的情况，得出该区域农田土壤污染是由该矿区生态环境修复前所产生的含金属灌溉水导致土壤中金属的积累...     

制订我国污染场地土壤风险筛选值的几点建议

近年来,我国大中城市陆续开展污染企业搬迁,环境管理上要求对搬迁场地进行商业开发前必须开展场地环境调查、风险评估和修复,客观上要求有一套场地环境评价标准和污染土壤修复标准.针对目前国内污染场地标准缺失及盲目引用国外相关筛选值出现的误区,分析了美国、荷兰和英国土壤筛选值差异的主要原因,为合理借鉴国外土壤筛选值及其制定方法学...     

生物炭修复与改良矿区重金属污染土壤的研究进展

概述了生物炭制备的关键影响因素及对矿区重金属污染土壤修复与改良作用的研究进展,在此基础上分析了生物炭修复与改良矿区重金属污染土壤的机理,提出了开展生物炭在实际矿区污染场地的长期性与稳定性行为研究,以及探讨生物炭与不同土壤改良剂的优化组合等建议。     

Site environmental assessment to an old paint factory in China

High ethyl-benzene and total petroleum hydrocarbons (TPHs) were found in the soil samples and groundwater samples during a site environmental assessment for an old paint factory in the city Changchun, Jilin province of China. The target old paint plant had been in operation for near 30 years by manufacturing resin and house paint. Driving force for this study was to identify potential environmental contamination existing in this paint factory which is located next to a new resident area under construction. The assessment result would be used as baseline environmental data input for remediation plan when the factory site will be changed into potential resident area in near future. The analytical data from the soil samples from different area of the factory which had high exposure to operation showed that solid waster storage area was contaminated with high heavy metals (Cd, Pb, and Zn) and waster paint storage areas were contaminated with ethyl-benzene, xylene and C9-C30 aromatic hydrocarbon solvent. The analytical data from the groundwater samples from different area of the factory showed that resin plant area and waster paint storage areas were contaminated with high concentration of naphthalene, ethyl-benzene and xylene which exceed the reference standard. Remediation action is recommended.     

中、英、美污染场地风险评估导则异同与启示

近年来,随着国家"退二进三"旧城改造政策的实施,全国几乎所有的大中城市正面临着大批多种污染行业企业的关闭和搬迁,这些搬迁企业遗留场地都存在着不同程度的环境与健康风险.开展定量评估人体健康与生态环境风险是建立我国工业污染场地管理体系不可缺少的技术手段,也是适合我国国情并走向可持续性(绿色)土壤与地下水修复及综合环境管理的...     

土壤污染修复技术研究进展

总结了当前针对污染土壤的物理化学、生物及联合修复技术研究进展,归纳了纳米材料、生物炭和表面活性剂等新兴修复材料的优缺点及应用情况。提出今后的研究方向为强化生物修复技术,开展联合修复技术、复合材料修复技术及土壤修复技术风险防范研究。     

Development of an Expert System for the Remediation of Petroleum-Contaminated Sites

Groundwater and soil contamination caused by light nonaqueous phase liquids (LNAPLs) spills and leakage in petroleum industry is currently one of the major environmental concerns in North America. Numerous site remediation technologies, generally classified as ex situ and in situ remediation techniques, have been developed and implemented to clean up the contaminated sites in the last two decades. One of the problems associated with ex situ remediation is the cost of operation. In recent years, in situ techniques have acquired popularity. However, the selection process of the desired techniques needs a large amount of knowledge. Insufficient expertise in the process may result in unnecessary inflation of expenses. In this study, petroleum waste management experts and Artificial Intelligence (AI) researchers worked together to develop an expert system (ES) for the management of petroleum contaminated sites. Various AI techniques were used to construct a useful tool for site remediation decision-making. This paper presents the knowledge engineering processes of knowledge acquisition, conceptual design, and system implementation in the project. The expert system was applied to a real-world case study and the results show that the expert system can generate desired remediation alternatives to assist decision-makers. The application case study constitutes partial validation of the prototype expert system.     

Remediating Over-Produced and Contaminated Aquifers by Artificial Recharge from Surface Waters

Recharging from open-surface water resources is investigated as a method for remediation of over-produced and contaminated aquifers. The hydraulic and contaminant modeling using the Modflow-2000 and MT3DMS simulation software are resorted for evaluation of the available options. Methodology is developed and illustrated for reviewing the alternative remediation approaches for optimal selection of the best remediation approach to aquifer recharging from surface waters. The effectiveness of the present systematic approach is demonstrated by identifying the best choice among the multifunctional artificial recharge options available for the Great Forest Park in Debrecen, Hungary.     

Assessment of soil screening levels due to ingestion and dermal absorption of chrysene and benzo[k]fluoranthene and appropriate remediation method for Dorson Abad

For years, the Dorson Abad region has been extremely polluted by Tehran Oil Refinery due to leaking from its underground pipelines, storage tanks, and evaporation ponds. To assess the concentrations of hazardous polycyclic aromatic hydrocarbon (PAH) compounds, soil samples were collected from the grounds at and adjacent to a polluted stream located in the study area. The samples were then analyzed, and the results revealed that 12 of the 16 USEPA PAHs were noticeably present in the soil, which, among them, benzo[k]fluoranthene and chrysene had the highest concentrations with averages of 357.17 and 173.38 mg/kg, respectively. A comparison of the obtained concentrations with the soil screening levels indicated that both benzo[k]fluoranthene and chrysene concentrations were substantially higher than EPA screening level values, signifying the necessity of soil remediation for these contaminants in the area. Techniques such as soil washing/flushing, high temperature thermal desorption, and solidification/stabilization were investigated for treatment of the contaminated soil; solidification/stabilization is recommended as an applicable and cost-effective remediation method for Dorson Abad due to the size of the region, relatively low cost of the binder (cement), and low volatility of benzo[k]fluoranthene and chrysene.