污染土壤淋洗修复技术研究进展

本文介绍了淋洗修复技术和淋洗装置在污染土壤修复技术中的应用,对有机物、重金属及放射性核素污染土壤淋洗修复技术的应用现状进行了总结和评价,还探讨了淋洗修复技术的发展方向及其应用前景。     

重金属污染土壤修复淋洗剂研究进展

针对不同重金属淋洗特性存在差异的问题,综述了绿色、高效淋洗剂的最佳淋洗条件、淋洗机理、化学反应实质及环境风险,为修复污染土壤选用或复配淋洗剂提供参考。总的来说,有机酸绿色、无污染,重金属去除效果较好,其中柠檬酸重金属去除率最高,控制pH=1～4、浓度0.2～0.4mol/L、时间4～12h的淋洗条件,能达到较好淋洗效果;人工螯合剂重金属去除效果好,但或存在环境风险或价格昂贵,仅GLDA生物可降解且重金属鳌合能力强,经GLDA淋洗后的土壤,需搁置28d后再资源化利用;表面活性剂重金属去除效果一般,通常作为淋洗助剂效果更好。笔者认为,加强修复不同类型复合重金属污染土壤的复配淋洗剂研究,淋洗剂复配应考察去除率、环境友好、经济可行三者综合最优,残留淋洗剂及淋洗剂降解后产物对环境影响,是未来的研究重点。     

重金属污染土壤修复技术综述

土壤重金属污染是当前重要的世界性环境问题之一。随着重金属污染土壤场地日渐增多,如何安全有效地修复并利用这些受污染的土壤已成为我国急需解决的环境和社会问题。本文介绍了重金属污染土壤常用修复技术的原理、优缺点,并重点介绍了土壤淋洗修复技术,对目前淋洗剂的应用情况、作用机制进行了评价。     

电镀废水污染区土壤重金属含量的测定及污染状况评价

运用原子吸收光谱法,测定了某地电镀废水污染区重金属污染土壤样品中cd、Ph、cu、zn4种元素的含量,RSD小于1％,加标回收率在92．78％-103．2％之间,表明测定结果可靠。依据测定数据、国家土壤环境质量二级标准、内梅罗指数法及潜在生态危害指数法,对电镀废水污染区土壤重金属污染状况进行评价。按二级标准评价结果为中度以上污染;以内梅罗综合污染指数法进行评价,土壤受到重度污染;用潜在生态危害指数法对污染生态风险进行评估,总潜在生态风险程度为重度。因此应对该区污染土壤进行治理。     

柴油污染饱和带土壤淋洗修复室内实验

文章介绍了土壤淋洗(SF)修复的原理,并对室内模拟的柴油污染饱和带土壤进行SF修复研究。经过SF修复20d后,室内模拟的柴油污染饱和带土壤接近修复终点,其TPH(总石油烃)平均由初始的13.50g/kg降至5.98g/kg,去除率达到55.70%。水驱SF修复方法对砂土层石油污染物去除效果显著。     

表面活性剂修复重金属污染土壤的研究

本文探讨了3种常用表面活性剂,十二烷基苯磺酸钠(SDBS)、十二烷基硫酸钠(SDS)、聚山梨脂(Tween-80)对被重金属铬、镉污染了的土壤的修复洗脱作用,以及被污染土壤对3种表面活性剂的吸附作用。淋洗实验结果表明,3种表面活性剂对土壤中的铬、镉有明显去除效果,聚山梨脂(Tween-80)对污染土壤中铬和镉的去除率分别为61.2%和37.06%。实验表明,土壤对3种表面活性剂均有较强的吸附作用,这种吸附作用对土壤重金属的去除会产生不利的影响。     

重金属污染土壤的修复方法及其在几类典型土壤修复中的应用

文中首先阐述了重金属污染土壤的途径与特点。介绍了当前几类主要的重金属污染土壤修复方法:物理化学方法、植物修复法、微生物修复法、动物修复法等的技术要点,详述了各自的技术特点及机理,并对它们的修复效能、环境友好性等进行了比较。从土壤的特性出发,区分出了3种典型的遭受重金属污染的土壤:农业土壤、城市土壤、矿区土壤,并从国内外最新的重金属污染修复实践中选取了适合各自土壤类型的修复方法进行了重金属污染土壤的治理探讨。最后,对土壤重金属污染修复技术的发展进行了展望。     

鼠李糖脂淋洗法去除土壤中重金属研究进展

鼠李糖脂是由铜绿假单胞菌（Pseudomonas aeruginosa）产生的一种阴离子型表面活性剂,具有高效、可生物降解等特征。鼠李糖脂具有能与重金属离子络合并降低界面张力的作用,因而可以作为淋洗法的提取剂用于去除受污染土壤中的重金属。本文着重阐述了鼠李糖脂去除土壤中重金属污染的原理及影响因素。     

铅蓄电池厂铅污染土壤清洗剂的筛选及清洗结果研究

为探索不同清洗剂对铅蓄电池厂区内铅污染土壤的去除效果及铅在不同粒径土壤清洗过程中的行为,本研究通过设定清洗剂的浓度梯度,对土样粒径分级、设定清洗时间等方法进行研究。结果显示EDTA和EDDS对铅具有最佳去除率(B点土107.19%和96.49%);盐酸对A点土最佳铅去除率为49.57%,B点、C点土在99.03%和89.93%;柠檬酸对3点位土的铅去除率最大为39.51%;鼠李糖脂对3份土铅去除率均低于10%。EDTA和EDDS在高浓度铅的去除中表现优势;柠檬酸适合去除中低浓度铅;盐酸的使用需考虑土壤本身情况。粗沙粒和细沙粒中的铅去除率高,粉粘粒的铅去除率低;最佳清洗时长为240min。此外,土壤本身理化性质对清洗剂效果的发挥有影响,清洗剂浓度过高可能降低清洗效率。该研究可为铅污染土壤清洗技术提供科学依据。     

土壤污染样品的采集与分析研究

本文对天津市某化工厂的土壤污染情况进行了调查。共设定了23个采样点，根据实际情况，对32个样品进行了pH、有机质及重金属等含量测定，并对测定结果进行了分析。     

Diversity of Soil Nematodes in Areas Polluted with Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs) in Lanzhou,China

This study investigated the soil nematode community structure along the Yellow River in the Lanzhou area of China, and analyzed the impact of heavy metals (Cd, Pb, Cr, Cu, and Zn) and polycyclic aromatic hydrocarbons (PAHs) on the nematode community. Soil samples from five locations (named A–E), which were chosen for soil analysis, showed significant differences in their heavy metal content (p < 0.01), as well as in the variety of nematodes (up to 41 genera) and families (up to 20) that were present. The different samples also differed significantly in the total PAH content (p < 0.05), as well as the six types of PAH present. Sites A–C showed the most severe contamination with heavy metals and PAHs; these sites had the lowest abundance of fungivores and omnivore/predators, but the proportion of bacteriovores was the highest (p < 0.05). Site E, in contrast, showed only minor pollution with heavy metals and PAHs, and it contained the highest abundance of plant parasites (p < 0.05). Several nematode ecological indicators were found to correlate with concentration of soil pollutants at all the sites tested: the maturity index (MI, in addition to plant parasites), plant parasite index (PPI), ΣMI (including all the soil nematodes), Shannon-Wiener diversity index (H′′), and Wasilewska index (WI). Disturbance to the soil environment was more severe when MI, ΣMI, and H′ values were lower. The results of the study show that the abundance and structure of the soil nematode communities in the sampling locations were strongly influenced by levels of heavy metals and PAHs in the soil. They also show that the diversity index H′ and the maturity index can be valuable tools for assessing the impact of pollutants on nematodes.     

Phytoremediation of Soil Polluted by Nickel Using Agricultural Crops

Soil pollution due to heavy metals is widespread; on the world scale, it involves about 235 million hectares. The objectives of this research were to establish the uptake efficiency of nickel by some agricultural crops. In addition, we wanted to establish also in which part of plants the metal is stored for an eventual use of biomass or for recycling the metal. The experiments included seven herbaceous crops such as: barley (Hordeum vulgaris), cabbage (Brassica juncea), spinach (Spinacea oleracea), sorghum (Sorgum vulgare), bean (Phaseolus vulgaris), tomato (Solanum lycopersicum), and ricinus (Ricinus communis). We used three levels of treatment (150, 300, and 600 ppm) and one control. At the end of the biological cycle of the crops, the different parts of plants, i.e., roots, stems, leaves, fruits, or seeds, were separately collected, oven dried, weighed, milled, and separately analysed. The leaves and stems of spinach showed a very good nickel storage capacity. The ricinus too proved to be a very good nickel storer. The ability of spinach and ricinus to store nickel was observed also in the leaves of cabbage, even if with a lower storage capacity. The bean, barley, and tomato, in decreasing order of uptake and storage capacity, showed a high concentration of nickel in leaves and stems, whereas the sorghum evidenced a lesser capacity to uptake and store nickel in leaves and stems. The bean was the most efficient in storing nickel in fruits or grains. Tomato, sorghum, and barley have shown a storage capacity notably less than bean. The bean appeared to be the most efficient in accumulating nickel in the roots, followed in decreasing order by sorghum, ricinus, and tomato. With regard to the removal of nickel, spinach was the most efficient as it contains the highest level of this metal per gram of dry matter. The ricinus, cabbage, bean, sorghum, barley, and tomato evidenced a progressively decreasing efficiency in the removal of nickel.     

石油污染对土壤生态的影响及修复技术分析

土壤修复现已逐渐成为环保领域新的热点。石油类污染物在土壤中迁移转化,使土壤的pH、有机质、含水率、生物群落结构等发生了改变。研究土壤理化性质、非生物因子和生物因子的动态关系是选择最佳修复技术的依据。介绍了目前主要的石油污染土壤修复技术及其优缺点和适用范围,提出理化一生物联用的原位修复技术是未来发展方向;石油污染物复杂多样,可通过构建复合高效菌群提高其生物修复效率。     

生长于铬污染土壤上石榴产品铬污染评价

研究了攀西地区铬污染土壤和正常土壤铬含量分布及其石榴样品铬污染情况。结果表明攀枝花大田石榴基地土壤铬含量在23．1—504mg／kg,平均值高达184mg／kg,超标率为26％,而对该基地的石榴果实进行两年连续监测结果表明,铬含量在0．0012—0．067mg／kg之间,平均为0．016mg／kg,大大低于相应产品标准（0．5mg／kg）,超标率为0％;会理石榴基地土壤铬含量在34．5—99．1mg／kg,平均值为69．0mg／kg,超标率为0％,该基地的石榴果实铬含量在0．0075—0．104mg／kg之间,平均为0．024mg／kg,大大低于相应产品标准（0．5mg／kg）,超标率为0％。形态分析表明土壤中铬99％以上都是以不被植物利用的残渣态存在,因此土壤总铬再高,其被植物可吸收部分却很少,这就导致了受铬污染的土壤却不一定能生产出污染石榴的原因。     

农村农田农药污染情况的研究

1.问题的由来昆阳镇第四中学位于昆阳镇的城乡之交、富饶肥沃的万全平原上。历史上就是有名的鱼米之乡。近年来由于城镇扩建、工厂外迁,以及农药化肥产品的滥用,周围环境受到污染,农产品的质量有所下降。本校的学生大多来自于周围农村,除少数家长经商、务工外,其他基本上是农民。学生十分熟悉周围的农田环境,亲身经历了这些变化,并且渴望进一步了解环境变化的原因以及对策。在我所任教的班上,不久前有位同学,因吃了农药污染的蔬菜而全家生病住院,同学们对此议论纷纷,并且向我询问关于农药危害性的各种问题。于是我考虑结合当地的实际进行一…