重金属污染土壤的强化电动修复技术研究进展

在土壤重金属污染日益严重的背景下,寻找一种简单高效的土壤修复技术刻不容缓。电动修复技术由于操作简单、处理污染物多样、修复快速、成本低廉等优点,成为重金属污染土壤修复领域的研究热点。简述了中国土壤重金属污染的现状,电动修复的原理及其影响因素,综述了近年来国内外有关强化电动修复重金属污染土壤的研究进展及国内外应用实例,分析了电动修复技术中存在的问题,最后指明了强化电动修复技术未来的研究方向。     

芽孢杆菌在重金属污染土壤修复中的研究进展

芽孢杆菌(Bacillus)因生长快、表面积大、抗逆性强等优点在重金属污染土壤修复方面表现出了广阔的应用前景.对近年来报道的具有重金属污染土壤修复功能的芽孢杆菌种类进行了总结,梳理了其作用机制,并对其处理重金属污染的分子生物学机理进行了分析归纳,结果显示,已有20种以上芽孢杆菌表现出了重金属污染土壤修复功能,主要修复机...     

土壤重金属复合污染及其化学钝化修复技术研究进展

土壤重金属污染往往是2种或2种以上的多种重金属并存的复合污染。与单一污染相比,重金属复合污染中元素或化合物之间存在相互作用以及对生态效应的综合影响,对其污染土壤的修复具有挑战性。目前,土壤重金属污染的修复主要集中在单一元素上,而对土壤多种重金属并存的复合污染的同时修复研究较少。化学钝化修复是基于向土壤中添加稳定化剂,通...     

重金属污染土壤原位钝化修复材料的最新研究进展

土壤环境关系到人们的身体健康,重金属污染土壤的修复一直以来是全球环境领域关注的焦点和研究的热点。重金属原位钝化修复技术是一种有前景的解决方案。其中,钝化材料是关键。着重介绍了不同类型重金属污染土壤原位钝化修复材料的修复原理、修复效果及应用情况,简要分析了修复材料的成本和效益,为重金属污染土壤原位钝化修复研究提供相关信息。     

电子废物拆解场地复合污染土壤修复技术研究进展

电子废物拆解场地土壤中含有重金属 、有机物等多种复杂污染物,对场地周围人群的健康与安全具有潜在威胁.概述了国内外复合污染土壤修复技术发展历程与研究现状,对比了化学修复、物理修复、生物修复技术在目标污染物、修复时间与修复效果上的差异,指出复合污染修复是未来研究的主要方向,修复技术将向多种技术联合应用发展、向绿色环保方向发...     

低成本含磷材料修复环境重金属污染的研究进展

低成本含磷材料包括磷灰石、骨粉、无机磷肥及无机磷酸盐,其对环境重金属污染的修复值得引起生态学、环境学更广泛的重视.详细介绍了:(1)各类低成本含磷材料结构性质;(2)含磷材料在修复土壤、沉积物、水体重金属污染方面的应用;(3)含磷材料修复环境重金属污染的机理及影响因素;(4)含磷材料修复环境重金属污染的效果评价等方面的研究进展及发展前景.     

磷矿粉修复重金属污染土壤的研究进展

重金属污染土壤的化学钝化修复技术可以有效控制重金属对植物及环境的危害。不同的改良剂对重金属污染土壤的改良效果不同,已有的研究表明难溶性磷矿粉是较好的选择。磷矿粉是一种性价比很高的改良剂,而且不会对环境造成破坏。总结了磷矿粉修复重金属污染土壤的化学机制和影响因素,重点综述了近年来不同粒径磷矿粉、改性磷矿粉修复重金属污染土壤的研究进展,旨在为重金属污染土壤的修复研究提供参考。     

韶关市翁源县铁龙林场土壤重金属修复

农田土壤重金属污染已成为影响我国社会经济全面发展的突出问题之一。以韶关市翁源县铁龙林场土壤修复示范工程为案例,分析了矿区重金属污染农田工程修复的设计流程、工程实施中的重点与难点、修复技术的筛选以及修复效果评估。其中重度污染区通过种植桑树降低土壤中重金属含量,并开展养桑产业链阻止重金属进入人体的研究,每年可收益9.0万~10.2万元·hm~(-2);而中轻度污染区通过采用钝化修复技术及低吸收作物品种筛选,有效降低农作物对重金属的吸收,保障农产品安全。为我国矿区重金属污染农田修复工程技术和管理提供参考。     

污泥耐受性草本植物的筛选及其对重金属Cu、Zn的富集

为探索植物修复污泥中重金属污染的可行性,配制不同污泥含量的介质土开展盆栽实验,对从河南、云南和上海等地收集的抗逆性强的19种草本植物进行污泥适应性筛选;研究了植物对污泥的生理响应及其对重金属Cu、Zn的吸收和分布.结果表明,上海市浦东新区白龙港污水处理厂污泥农用是可行的,农用时污泥比例应控制在60％以下;筛选出三叶鬼针草、稗子、荆芥和金叶马兰4种污泥耐受性植物;三叶鬼针草具有修复重金属Cu、Zn污染土壤的潜力;稗子具有修复重金属Zn污染土壤的能力;金叶马兰具有修复重金属Cu、Zn污染土壤的能力.     

铁改性生物炭的制备及其在重金属污染土壤修复技术中的应用进展

生物炭已被广泛应用于修复重金属污染土壤,但粒径大、力学性能差、吸附点位较少等缺点限制了其应用。由铁基化合物和生物炭制备的铁改性生物炭,可优化生物炭的性能,弥补生物炭修复能力的不足,表现出良好的重金属钝化效果。综述了铁改性生物炭的制备方法,以及该材料对重金属污染土壤修复的研究进展：介绍了铁改性生物炭的制备方法和常用表征手段;总结了制备及修复过程中的主要影响因素(原材料、温度、投加量、修复时间等);从静电作用、离子交换、络合、氧化还原、共沉淀作用等方面阐明了铁改性生物炭对重金属的固定化机制;分析了施用铁改性生物炭对土壤微生态的影响;最后指出了铁改性生物炭材料在应用中可能存在的问题。以期为铁改性生物炭在重金属污染土壤修复中的应用提供理论依据。     

Using biochar for remediation of soils contaminated with heavy metals and organic pollutants

Soil contamination with heavy metals and organic pollutants has increasingly become a serious global environmental issue in recent years. Considerable efforts have been made to remediate contaminated soils. Biochar has a large surface area, and high capacity to adsorb heavy metals and organic pollutants. Biochar can potentially be used to reduce the bioavailability and leachability of heavy metals and organic pollutants in soils through adsorption and other physicochemical reactions. Biochar is typically an alkaline material which can increase soil pH and contribute to stabilization of heavy metals. Application of biochar for remediation of contaminated soils may provide a new solution to the soil pollution problem. This paper provides an overview on the impact of biochar on the environmental fate and mobility of heavy metals and organic pollutants in contaminated soils and its implication for remediation of contaminated soils. Further research directions are identified to ensure a safe and sustainable use of biochar as a soil amendment for remediation of contaminated soils.     

用水生生物对重金属污染土壤进行生态毒理评价

应用斜生栅藻（Scenedesmus obliquus）和明亮发光杆菌T3（Photobacterium phosphoreum）急性毒性实验方法对重金属污染土壤的进行生态毒理评价，结果表明，斜生栅藻的生长繁殖率和发光菌的相对发光度与土壤中的重金属含量明显相关，并且随重金属投加量的增加，其生长繁殖率和发光度逐渐降低。对3种测试参数进行比较可知，斜生栅藻细胞数增长率是最敏感的土壤毒性检测指标。土壤的毒性在复合污染的条件下比在单一污染的条件下高很多。本研究的结果可以为污染土壤的优先修复提供理论依据。     

用水生生物对重金属污染土壤进行生态毒理评价

应用斜生栅藻(Scenedesmusobliquus)和明亮发光杆菌T3(Photobacteriumphosphoreum)急性毒性实验方法对重金属污染土壤的进行生态毒理评价,结果表明,斜生栅藻的生长繁殖率和发光菌的相对发光度与土壤中的重金属含量明显相关,并且随重金属投加量的增加,其生长繁殖率和发光度逐渐降低。对3种测试参数进行比较可知,斜生栅藻细胞数增长率是最敏感的土壤毒性检测指标。土壤的毒性在复合污染的条件下比在单一污染的条件下高很多。本研究的结果可以为污染土壤的优先修复提供理论依据。     

Effects of remediation train sequence on decontamination of heavy metal-contaminated soil containing mercury

When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (>50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550°C with a heating rate of 5°C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However, executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550°C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg.

ImplicationsA remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants.     

Zinc tolerance and uptake by <Emphasis Type="Italic">Arabidopsis halleri ssp. gemmifera</Emphasis> grown in nutrient solution

Background, aim, and scope  

Zinc is an essential micronutrient element but its concentrations found in contaminated soils frequently exceed those required by the plant and soil organisms, and thus create danger to animal and human health. Phytoremediation is a technique, often employed in remediation of contaminated soils, which aims to remove heavy metals or other contaminants from soils or waters using plants. Arabidopsis (A.) halleri ssp. gemmifera is a plant recently found to be grown vigorously in heavy metal contaminated areas of Japan and it contained remarkably high amount of heavy metals in its shoots. However, the magnitude of Zn accumulation and tolerance in A. halleri ssp. gemmifera need to be investigated for its use as a phytoremediation plant.     

Potential of Brassic rapa, Cannabis sativa, Helianthus annuus and Zea mays for phytoextraction of heavy metals from calcareous dredged sediment derived soils

Remediation of soil pollution is one of the many current environmental challenges. Anthropogenic activity has resulted in the contamination of extended areas of land, the remediation of which is both invasive and expensive by conventional means. Phytoextraction of heavy metals from contaminated soils has the prospect of being a more economic in situ alternative. In addition, phytoextraction targets ecotoxicologically the most relevant soil fraction of these metals, i.e. the bioavailable fraction. Greenhouse experiments were carried out to evaluate the potential of four high biomass crop species in their potential for phytoextraction of heavy metals, with or without with the use of soil amendments (EDTA or EDDS). A calcareous dredged sediment derived surface soil, with high organic matter and clay content and moderate levels of heavy metal pollution, was used in the experiments. No growth depression was observed in EDTA or EDDS treated pots in comparison to untreated controls. Metal accumulation was considered to be low for phytoextraction purposes, despite the use of chelating agents. The low observed shoot concentrations of heavy metals were attributed to the low phytoavailability of heavy metals in this particular soil substrate. The mobilising effects induced by EDTA in the soil were found to be too long-lived for application as a soil amendment in phytoextraction. Although EDDS was found to be more biodegradable, higher effect half lives were observed than reported in literature or observed in previous experiments. These findings caution against the use of any amendment, biodegradable or otherwise, without proper investigation of its effects and the longevity thereof.     

Evaluation of remediation process with plant-derived biosurfactant for recovery of heavy metals from contaminated soils

A washing process was studied to evaluate the efficiency of saponin on remediating heavy metal contaminated soils. Three different types of soils (Andosol: soil A, Cambisol: soil B, Regosol: soil C) were washed with saponin in batch experiments. Utilization of saponin was effective for removal of heavy metals from soils, attaining 90-100% of Cd and 85-98% of Zn extractions. The fractionations of heavy metals removed by saponin were identified using the sequential extraction. Saponin was effective in removing the exchangeable and carbonated fractions of heavy metals from soils. In recovery procedures, the pH of soil leachates was increased to about 10.7, leading to separate heavy metals as hydroxide precipitates and saponin solute. In addition recycle of used saponin is considered to be effective for the subsequent utilization. The limits of Japanese leaching test were met for all of the soil residues after saponin treatment. As a whole, this study shows that saponin can be used as a cleaning agent for remediation of heavy metal contaminated soils.     

酸雨对污染环境中重金属化学行为的影响

综述了酸雨对污染环境中重金属化学行为的影响。在酸雨作用下 ,不同环境介质中重金属活性明显增强 ,化学形态转化明显 ,迁移能力和生态危害能力亦明显加强。探讨了控制酸雨发生、重金属污染环境修复技术以及开展复合污染环境化学风险评价的必要性     

EDTA强化电动力学修复重金属复合污染土壤

在自制的电动力学装置中,研究多种重金属复合污染土壤的电动力学修复,通过在阴极添加络合剂EDTA来提高修复效率。实验结果表明,EDTA的引入提高了修复过程中的电流值,且EDTA与重金属的络合提高了污染物向电极液的迁移效率,从而强化了电动力学修复效果。在设定的浓度(0、0.01、0.02、0.05和0.1 mol/L)中,0.1 mol/L的EDTA具有最佳的修复效率。在此实验条件下,污染土壤中的总铜、总铅和总镉的去除率分别为90.2%、68.1%和95.1%。电动力学修复后,对土壤重金属进行化学形态分析,发现电动力学修复显著改变了土壤重金属存在形态,修复后土壤中的铜、铅、镉主要以较稳定的有机态和残余态形式存在,显著降低了对周边生物和环境的毒害。