石油污染土壤的生物修复研究进展

生物修复技术是解决环境污染、恢复被人类活动破坏的生态系统、实现人类社会可持续发展的重要手段之一,它具有速度快、消耗低、效率高、成本低、反应条件温和以及无二次污染等显著优点.本文主要介绍了生物修复的原理和特点,石油污染土壤的各种生物修复技术:微生物修复技术、植物修复技术和菌根根际生物修复技术的研究和应用进展.     

石油污染土壤中正十六烷降解菌的效果研究

从山东东营石油污染土壤中驯化筛选出一株正十六烷降解菌TZSX2,经生理生化和16S r DNA基因测序,通过构建细菌系统发育树确定其为红球菌属(Rhodococcus)。通过不同环境因子对TZSX2的生长情况和其对正十六烷的降解率的影响研究,确定菌株TZSX2的最适生长和降解温度为28~36℃,对正十六烷的降解率超过30%;TZSX2能够耐受较高浓度的正十六烷,在正十六烷浓度为2 m L·L~(-1)时,降解率为79%,正十六烷浓度为20 m L·L~(-1)时,降解率仍可达到12%;在碱性条件(pH=9)下对初始浓度为10m L·L~(-1)的正十六烷的降解率高达91%。综上,所筛选的TZSX2菌株可以耐碱性,适用于极端环境中石油污染的修复,对高浓度的正十六烷具有优异的降解效果。     

An Improved Gravimetric Method to Determine Total Petroleum Hydrocarbons in Contaminated Soils

A gravimetric method to determine heavy fractions of total petroleum hydrocarbons (TPH) in soils is reported. The method was adapted and calibrated by modifying previous standard methods published, incorporating energy and cost savings where possible. Artificially contaminated soils with different organic matter content, and aged in stationary mode for a period of 8 months were used for calibration. Insufficient solvent evaporation was identified as the most prevalent and largest positive interference in the gravimetric detection. To overcome this, while minimizing the need for heating, a combination of three 10-min rotary evaporator steps and 30 min of vacuum in a desiccator were applied, for a total solvent volume of 60 ml. Hexane was chosen as the extraction solvent and a 40–60 min treatment in an ultrasound bath of 260 W was found suitable to extract 80–95% of TPH extracted by the Soxhlet method. Finally, the use of silica gel for cleanup of co-extracted natural organic matter was found unnecessary, because of the low amounts co-extracted for soils with up to 5% organic carbon, and because the chemical nature of the co-extracted organic matter prevents its selective adsorption to silica.     

考虑非点源影响的水源地水库水质预测研究

联合应用流域非点源AnnAGNPS模型和水库水质CE-QUAL-W2模型,研究了非点源污染对陕西省金盆水库水质影响。利用AnnAGNPS模型输出黑河流域非点源污染负荷,将其转化为金盆水库入库浓度作为CE-QUAL-W2模型的输入,对黑河金盆水质进行预测。结果表明:(1)非点源污染在洪水期时对金盆水库水质有较大影响,而在非洪水期时非点源污染对水库水质影响不显著;(2)非点源污染对水库纵向和垂向水质的影响存在差异性;(3)林地对流域非点源污染的削减起到很大作用;(4)在对水库水质进行预测时,应对洪水期和非洪水期的非点源污染区别对待。     

玉米草（Zea Mexicana）与海藻寡糖联合修复石油烃污染土壤的研究

采用玉米草及海藻寡糖联合修复技术研究了石油污染土壤的修复效果,对修复过程中酶活性变化进行了测定,并采用变性梯度凝胶电泳（DGGE）技术测定了土壤中微生物群落的变化。结果表明,种植玉米草可以有效提高土壤中石油烃的降解,与对照相比石油烃降解率增加了11%;加入不同浓度海藻寡糖进一步增加了石油烃的降解效果,降解率最高达到28.6%。种植植物及加入海藻寡糖可以有效提高多酚氧化酶、脱氢酶及尿酶的活性。PCR-DGGE结果表明植物种植及海藻寡糖的加入增加了土壤中微生物数量,其微生物群落结构与未种植植物及修复前土壤相比发生了较大的变化。     

Studies of Soils, Soil Water and Stream Water at a Small Catchment near Guiyang, China

Acid deposition is considered to be a major environmental problem in China, but information about effects on soils and waters is scarce. To contribute to increased knowledge about the problem a small catchment (about 7 ha) in the outskirts of Guiyang, the provincial capital of Guizhou in south-western China, was instrumented for collection of precipitation, throughfall, soil water and stream water. In addition soil samples have been collected and analyzed for key properties. Median pH in the precipitation is 4.40 (quartiles: 4.19 and 4.77) and the median sulfate concentration 228 µeq/L (quartiles: 147 and 334 µeq/L). The dry deposition of both SO₂ and alkaline dust is considerable. The sum of wet deposition of sulfate and dry deposition of SO₂ has been estimated to about 8.5 gSm^-2yr^-1. The total S-deposition may be somewhat higher due to dry deposition of sulfate and occult deposition. In soil water, SO₄ ^2- is the major anion, generally ranging from 300 to 2500 µeq/L in the different plots. Calcium is an important cation, but there is also a considerable contribution of aluminum from the soil. In some of the plots the concentrations of inorganic monomeric aluminum (Ali) are typically between 200 and 400 µm. Potential harmful levels of aluminum and/or high Ali/(Ca²⁺ + Mg²⁺) molar ratios occur in the catchment, but damages to vegetation have not yet been reported. In most cases exchangeable aluminum accounts for between 75 and 95% of the total effective cation exchange capacity (CEC_E) in the mineral soils. The aluminum chemistry cannot easily be explained by conventional models as the Gaines-Thomas ion-exchange equation or equilibrium with an Al(OH)₃ mineral phase. The stream water is generally less acidic and has considerably lower concentrations of aluminum than the soil water, even though quite acid events have been observed (pH < 4.4). The median pH values are 4.9 and 5.0 in the two first order streams and 6.3 in the dam at the lower boarder of the catchment.     

Surfactant-Enhanced Soil Washing for Removal of Petroleum Hydrocarbons from Contaminated Soils: A Review

An increase in energy demand leads to further exploration, transportation, and utilization of petroleum, which creates severe soil contamination because of recurrent accidents and oil spills. Remediation of these contaminated soils is challenging. Among many treatment methods practiced for remediation of petroleum-contaminated soils, surfactant-enhanced soil washing has been widely practiced as a preferred treatment option, as it is a fast and environmentally accepted method. In this paper, we review research undertaken on various anionic, nonionic, cationic, biological, and mixed surfactants for the remediation of petroleum hydrocarbon-contaminated soils. Upcoming surfactants like gemini and switchable surfactants are summarized. We assess the challenges and opportunities of in-situ and ex-situ soil washing, the mechanisms of surfactant-enhanced soil washing, and the criteria to follow for surfactant selection. Furthermore, we briefly discuss the operational and environmental factors affecting soil washing efficiency and soil and surfactant properties affecting surfactant adsorption. We also describe the advantages of coupling soil washing with effluent treatment and surfactant reuse challenges and opportunities. Moreover, challenges and possible new directions for future research on surfactant-enhanced soil washing are proposed.     

水分管理对重金属污染土壤植物修复效果的影响研究综述

随着人们生活水平的提升、工业化进程和城市化的不断发展,土壤重金属污染已成为当今社会发展面临的一个很严峻的环境问题,因此加强土壤重金属污染的修复刻不容缓。近年来兴起的植物修复技术相比于其它修复技术有着良好的发展前景,但植物修复效率一直是困扰该技术的难题。大量研究表明,水分管理会引起土壤理化性质及重金属形态的改变,同时改变植物体内重金属的含量和迁移。本文在前人的研究基础上,综述了水分管理对土壤物理、化学、生物学性质以及植物本身的影响,分析了不同水分条件下植物的修复效率,提出了未来发展建议,为保证我国粮食安全和农业绿色发展提供理论基础和实践依据。     

石油污染土壤的生物修复研究进展

对于石油污染土壤的修复,其生物修复具有环境友好、费用较低等特点,是最具应用前景的土壤修复技术。本文较全面地介绍了石油污染土壤生物修复的影响因素、石油污染土壤的生物修复技术,并对该领域今后的研究重点进行了展望。     

贵州铅锌冶炼区农田土壤镉铅有效性评价与预测模型研究

农田土壤重金属的不同活性库分布和土壤-溶液分配模型能够提供重金属的生物有效性和浸出能力等信息,因而在风险评价和修复实践中非常重要。本研究采集毕节铅锌冶炼区30个历史污染农田土壤,同时在贵州省范围内采集5种类型背景土壤制成不同浓度Pb/Cd单一污染土壤;经3个月老化,分别测定由0.43 mol/L HNO_3、0.1 mol/L HCl和0.005 mol/L DTPA提取态表征的重金属反应活性库以及由0.01 mol/L CaCl_2提取态表征的直接有效库;分析铅锌冶炼区农田土壤Cd、Pb不同有效库的分布特征,建立土壤-溶液分配模型,并讨论土壤理化性质的影响。结果表明:历史污染土壤中Cd和Pb的直接有效库占全量比例分别比人工污染土壤低4倍和223倍,然而历史污染土壤Cd和Pb的反应活性库(0.43 mol/L HNO_3提取态)占全量比例要高于相应人工污染土壤中的比例。拓展Freundlich形式吸附方程能够准确描述各提取态表征的Cd和Pb活性库与土壤全量Cd和Pb的关系,尤其0.43 mol/L HNO_3提取方法能够克服土壤理化性质对土壤Cd和Pb提取的影响而与总量建立极显著的相关关系。pH依附性Freundlich吸附方程准确描述了Cd和Pb的总反应活性库分别与土壤溶液Cd和Pb的关系,对于Pb而言,还要考虑土壤有机质和有效磷的影响。本研究可为矿区农田土壤重金属污染评价、修复以及农田有效态标准的推导提供参考。     

污染土壤的固化/稳定化处理技术研究进展

固化/稳定化技术具有快速、有效、经济等特点,广泛应用于各类危险废物的处理,但土壤方面的应用还比较匮乏.本文介绍了近年来污染土壤固化/稳定化研究和应用的现状,概括了从实验室研究、现场试验到处理工程的流程,重点对常见固化系统、主要影响因素、处理效果评价、固化机理研究和修复工程的实施等方面的研究进展加以总结,并对其发展趋势加以展望.     

Magnetic Study of Weakly Contaminated Forest Soils

Water, Air, &; Soil Pollution - This paper reports on magnetic and magnetomineralogical studies of forest soils from Krkono?e (Giant Mountains) National Park in the Czech Republic....     

北京密云水库集水区景观生态分类

景观生态分类是研究景观健康的基础,它不仅要强调景观空间结构的分异,还应该突出景观功能与过程的关联统一。以遥感影像和地形图件为基础,结合二类资源清查资料和GPS实地布点,借助于ARC View和Frag-stats软件,对集水区森林景观进行了结构分类,并结合生态经济分区,按照分类经营和森林景观健康评价需要,将集水区森林景观归并为生态型、经济型和生态经济型三种功能类型。集水区森林景观多样性指数为2.163 6,均匀度指数为0.688 3,优势度指数为0.682 6,斑块密度为0.114 6,分形维数为1.047 6,各种森林景观类型受人类活动干扰普遍较为严重,景观斑块面积较破碎、形状较规则。分类结果为诊断和维护森林景观健康奠定了良好基础。     

有机磷农药污染土壤的微生物降解研究进展

有机磷农药是目前我国使用量最大的农药之一,严重污染环境和生态系统,并通过食物链在生物体内富集,进而危害人类健康。微生物降解技术具有降解效率高、代谢途径多、无二次污染的优势,是目前清除环境中有机磷农药的主要手段,能有效降低有机磷农药的危害。目前有机磷农药的降解微生物主要是通过实验室纯培养方法获得,与自然生态环境中存在的降解功能性微生物信息差异较大,而利用不可培养方法识别功能性微生物的技术具有广阔的应用前景。本文从有机磷农药的使用情况及引发的环境问题出发,概述了有机磷农药在土壤中的迁移转化途径,稳定同位素探测技术和磁性纳米材料等不可培养方法对有机磷农药降解功能性微生物的识别,微生物降解有机磷农药污染土壤的功能基因、降解途径及降解机理;探讨了植物–微生物联合修复在有机磷农药污染土壤修复中的作用,并分析了环境因子及农药自身性质对有机磷农药降解的影响;最后,讨论了微生物降解技术存在的问题及今后研究方向。     

重要水源地水质问题及保护对策研究

本文针对重要水源地水环境和水安全问题,以福建为例系统分析了主要河流及水源地水质现状、污染程度以及水质变差的主要问题与动因。以科学发展观为指导,提出了应加强水源地水质污染影响机制与管理模式的研究;科学规划、推广山地水土保持新技术,建设生态果园;加大投入,建立水源地补偿机制;全面推行清洁生产,从源头控制污染;加大宣传力度,强化生态意识的综合治理体系与生态调控保护对策。     

Sorption,Release and Forms of Mercury in Contaminated Soils Stabilized with Water Treatment Residual Nanoparticles

This study was carried out to assess, for the first time, the effect of water treatment residual nanoparticles (nWTR) on mobility, fractionation and speciation of Hg in two arid zone soils. Nanoscale water treatment residual application markedly reduced cumulative Hg released from soils studied, with the effect increasing as the nWTR application rate increases. The power function kinetic model well described the desorption process from soils and soils with nWTR. Meanwhile, application of nWTR greatly increased the association of Hg with the residual fraction and increased the most stable Hg species (Hg (OH)₂ amor), which in turn enhanced Hg immobilization in the studied soils. Fourier transmission infrared spectroscopy analysis indicated the involvement of nWTR in the retention of Hg (II) and revealed that sorption occurred mainly through OH groups, which suggest inner‐sphere adsorption of Hg ions to surface functional groups on nWTR. These results demonstrated the feasibility of using a green and low‐cost nWTR as best management practice to retain and immobilize excess Hg in contaminated soils. Copyright © 2016 John Wiley & Sons, Ltd.     

Short-Term Impacts of Pecan Waste By-Products on Soil Quality in Texturally Different Arid Soils

Three arid soils (clay loam (CL), sandy clay (SC), and sandy loam (SL)) were amended with pecan waste products (ground pecan shells (PSHs), ground pecan husks (PHUs), and ground pecan shell biochar (PSB)), at a rate of 45 Mg/ha, packed inside cylindrical rings and kept in a humid chamber for 4 weeks. Measurements taken included volumetric moisture content as the soil dried out for 7 days, wet aggregate stability (WAS), permanganate oxidizable carbon (POXC), nitrate-nitrogen, extractable phosphorus (Olsen-P), and water-extractable potassium (K). Significant effects of soil texture, soil amendment, and their interaction were observed for all measurements. Generally, the amendments led to significant improvement in Olsen-P, K, POXC, and WAS, while amendments’ impacts on soils of different textures varied. Short-term moisture retention was dependent on soil texture, with PHU and PSB treatments having higher soil moisture retention in SL and CL soils but not in SC soil.     

不同钝化剂对铜污染土壤原位钝化修复

考察了磷酸二氢钾、碳酸钙、硅酸钠、自制草木灰和自制生物质炭5种钝化剂对Cu污染土壤的钝化修复效果,对修复后的土壤进行了X射线衍射(XRD)分析;同时,对欧共体标准物质局提出的三步提取法(简称BCR法)进行了适当的改进,并运用改进的BCR法对Cu在土壤中的形态进行分析,以探讨不同钝化剂的作用机理。结果表明,5种钝化剂的投加量分别为50、100、20、20和20 g/kg时,对土壤钝化修复效果最佳,投加钝化剂后,土壤中可交换态Cu含量快速减少、残渣态Cu含量快速增加。其中,自制草木灰由于提高土壤p H更易与Cu生成沉淀,对Cu的钝化效果最佳,该钝化剂使有效态Cu含量减少53%,可交换态Cu含量减少49.2%,残渣态Cu含量增加4.7倍,有效地降低了Cu的生物毒性。     

Catchment Basin Management of Water

With the declaration of the State of Israel in 1948, Israel inherited the Ottoman law for water and not the English Rule of Riparian Rights. The Ottoman law allowed the State to control the water sources and, in fact, did not allow private ownership of water sources. In its early years, Israel promulgated some of the most forward looking legislation in the world concerning protection of water sources. But as time went on, Israel lost its preeminence in the water protection field, while other countries revised their water laws in light of the environmental revolution. It is now time for Israel to redesign its water system along catchment basin lines.