生物炭吸附重金属的研究进展

生物炭是一种废弃物资源化利用的产物。作为新型环境功能材料,生物炭以其优良的环境效应和生态效应成为环境科学等学科研究的前沿热点。因其孔隙结构发达、比表面积巨大和独特的表面化学性质,对环境介质中的重金属离子有很强的吸附作用,进而影响了重金属离子的迁移与归宿。主要从生物炭的材料来源、吸附重金属离子的机制、影响因素以及对土壤中重金属生物有效性的影响等方面进行综述,并提出生物炭吸附重金属离子的未来研究方向。     

难降解氯代有机物污染环境的生物修复技术研究进展

氯代有机物是一类在生产和生活中广泛应用并被大量排放到环境中的难降解有机污染物质,一旦进入生态环境,就会在水体、土壤和底质中长期残留,并在食物链中不断积累、富集,从而对生物体产生危害。因此,对受这类难降解有机物污染的环境修复是目前所迫切需要解决的环境问题之一。基于物理和化学修复方法成本较高易造成二次污染,文中探讨了国内外生物修复技术的研究进展,并对难降解氯代有机物污染环境修复的研究方向进行了展望,由于环境中的污染物质复杂多变,联合生物修复技术将成为未来的研究热点。     

普者黑湿地小流域土壤总磷分布及污染风险评价

以普者黑湿地小流域为研究对象,分别采集农田0～5cm、草甸0～5cm及湖滨湿地0～5、5～10、10～15cm的土壤样品,分析干、湿季土壤总磷的分布特征。结果表明:(1)在水平分布上,干季表层土壤总磷含量为农田草甸湖滨湿地,湿季表层土壤总磷含量为农田湖滨湿地草甸;在垂向分布上,干、湿季土壤总磷含量分布一致,均为表层富集明显。(2)流域内土壤总磷含量均为湿季大于干季。(3)单因子指数评价结果显示,水平方向上,干、湿季农田与草甸表层土壤总磷均为重度污染,垂直方向上,干季湖滨湿地土壤总磷均为轻度污染,湿季均为重度污染。总体而言,普者黑流域湿季土壤磷污染程度较干季高。     

鸭绿江口及毗邻浅海沉积物重金属的分布特征与风险评价

采用重金属的富集系数和多金属污染度分析鸭绿江口及毗邻浅海沉积物重金属的分布特征.结果表明:鸭绿江口及毗邻浅海沉积物Cu、Hg和Cd属于重要的污染因子;多金属污染度高强度分布区与高含沙量区存在对应关系,但对重金属富集影响更大的是人类活动.采用潜在生态风险指数法与生物效应阈值浓度法2种评价方法进行研究区的生态风险评价,结果...     

土壤/沉积物中重金属生物有效性和生物可利用性的研究进展

土壤/沉积物中重金属的污染问题越来越引起重视,而重金属在环境中的生态风险与其生物可利用性和生物有效性密切相关。在总结国内外研究的基础上,明确了重金属生物有效性和生物可利用性的定义;概述了用于研究土壤/沉积物中重金属生物有效性的生物模型(小鼠、猪、兔子等);总结了用于研究土壤/沉积物中重金属生物可利用性的几种体外方法,包括模拟人类肠胃消化(PBET、SBRC、UBM等)和底栖生物消化;分析了土壤/沉积物中重金属生物有效性和生物可利用性的关键影响因素(土壤/沉积物理化性质和分析方法)。提出了未来土壤/沉积物中重金属生物有效性和生物可利用性的研究方向,以期为重金属生态风险的评价和控制提供参考。     

植物材料中氟化物分析方法综述

植物对环境中氟化物(特别是大气中的氟化物)有高度的富集作用,使氟化物在生态系统中的变化甚为复杂,并对人类的健康产生潜在的影响。生物样品中氟化物的分析,近年来有较多的研究。我们主要讨论近年来有关植物中氟化物的分析方法以及与此有关的氟化物微量分析。一、测定氟化物方法概述测定氟化物的方法很多,但是适于植物分析的微量方法,较早应用的有容量法,但其灵敏度较低,应用逐渐减少。近年来主要应用的有分光光度法、氟电极法、活化分析法以及极谱分析和发射光谱分析法。     

杀虫双环境影响和降解研究

杀虫双是由我国自行开发的沙蚕毒系的一个农药新品种,本研究旨在提供该农药对环境的影响及其降解特性的资料,为杀虫双的环境安全性评价、合理使用和出口创汇注册提供科学依据,完成了下述各项内容的研究: 1.环境样品(土壤、水和生物)的测试方法研究,以建立高灵敏度的仪器分析技术,解决杀虫双环境样品的痕量检测方法。 2.杀虫双在农作物(水稻)和土壤中的残留水平和消解动态研究,并获得南北两地两年的残留数据和杀虫双在作物和土壤中消失动态资料。 3.杀虫双在土壤中的降解特性和淋溶动态研究,主要完成杀虫双在土壤中的降解动力学特性(包括降解半衰期)、环境因素(温度等)对杀虫双降解过程的影响以及杀虫双在土壤中淋溶速率及对地下水可能影响的研究。 4.杀虫双在模拟水生和陆-水生态系统中的分配特性研究,主要完成~(36)S-杀虫双在模拟生态中的迁移,转化及归宿研究。 6.杀虫双对水生生物的影响,主要完成杀虫双对水生生物的急性毒性、慢性毒性和致突变试验,以及蓄积水平等研究。     

土壤中邻苯二甲酸酯分布特征、来源及风险评价研究进展

邻苯二甲酸酯(PAEs)作为环境中广泛存在的一类内分泌干扰物,其污染问题已经引起广泛关注。针对土壤中PAEs的检测方法、分布特征、环境来源和风险评价等方面进行综述。土壤样品前处理及分析测试过程中环境、试剂等存在痕量的目标化合物会影响最终检测结果的准确性,排除此环节中的污染干扰尤为重要,色谱—质谱联用技术是精准分析此类化合物的发展方向。中国土壤中PAEs普遍检出,PAEs含量与人类活动和生产方式密切相关,其控制标准和风险评价大多采用国外标准,一定程度上影响了中国不同类型及功能区划土壤质量评价的科学性和客观性。环境友好分析测试技术的开发应用、风险评价体系的建立健全及环境溯源技术的发展将是今后土壤中PAEs研究的主要方向。     

新疆某矿冶区周边土壤重金属生物有效性与生态风险评价

矿业活动对土壤系统良性运转带来较大的环境负荷,矿区周边土壤重金属污染风险评估是土壤污染防治和资源可持续开发的关键。在应用单因子污染指数法、潜在生态风险指数法、风险评价编码法(RAC),并结合空间分析和冗余分析手段的基础上,对新疆某矿冶区周边土壤重金属生物有效性和生态风险进行了系统研究。结果表明:研究区土壤As、Cu、Mn和Cd超标率分别为88%、38%、49%和24%;土壤Mn、Zn、As和Cd弱酸可溶态高值区主要集中在尾砂库和收砷房的附近区域。单因子污染指数评价揭示As和Cu污染累积较为严重。潜在生态风险评价显示,As、Cd和Cu生态风险较高,Mn为低生态风险。风险编码法(RAC)评价结果进一步揭示Mn和Cd具有显著的土壤迁移风险。冗余分析结果显示,空间异质性是影响土壤重金属弱酸可溶态含量变异的主要因素。土壤pH和重金属弱酸可溶态是影响潜在生态风险指数(RI)的2个重要因素。综合风险评价手段与多尺度分析方法的联合应用有助于提高区域风险评价的准确性。     

土壤重金属钝化材料生物炭的研究进展

原位钝化法作为一种快速有效的土壤重金属污染治理方法得到了广泛的应用。生物炭是由生物质在缺氧环境下热解而成的一种含碳材料,具有精细的孔隙结构、较大的比表面积和丰富的表面官能团,能够有效地钝化土壤中的重金属,降低其生物有效性,是一种应用前景广阔的钝化材料。综述了影响生物炭对土壤重金属钝化效果的主要因素、钝化机制以及生物炭的改性方法。寻找钝化持效性好的生物炭材料,深化研究生物炭与不同形态重金属的作用机制,有利于更好地将生物炭钝化材料应用于重金属污染土壤的修复。     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.     

Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry

Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.     

The variation of street air levels of PAH and other mutagenic PAC in relation to regulations of traffic emissions and the impact of atmospheric processes

The occurrence of particle associated PAH and other mutagenic PAC was determined in 1996 in the street air of Copenhagen. In addition, particle extracts were tested for mutagenicity. The measurements were compared with previous measurements in 1992/1993. The levels had decreased in this period. The decrease was caused by an implementation of light diesel fuels for buses and the exchange of older petrol-driven passenger cars with catalystequipped new ones. About 65% of the reduction was caused by the application of the light diesel fuels. Under special conditions, chemical processes in the atmosphere produced many more mutagens than the direct emissions. The concentrations of S-PAC and N-PAC were 10 times lower than those of PAH, while the levels of oxy-PAH were in the same order of magnitude as those of PAH. Benzanthrone, an oxy-PAH, is proposed to be formed in the atmosphere in addition to direct emissions. Benzo(a)pyrene, often applied as an air quality criteria indicator, was photochemically degraded in the atmosphere. A strong increase in the mutagenic activities was observed to coincide with a depletion of benzo(a)pyrene.     

Teratological effects of pesticides in vertebrates: a review

Abstract

In the last decades, the use and misuse of pesticides in the agriculture have increased, having a severe impact on ecosystems and their fauna. Although the various effects of pesticides on biodiversity have been already documented in several studies, to our knowledge no consistent overview of the impact of pesticides in vertebrates, both terrestrial and aquatic, is available. In this review, we try to present a concise compilation of the teratogenic effects of pesticides on the different classes of vertebrates – mammals, birds, reptiles, amphibians and fish.     

Book review

The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.     

Patterns of volatile metabolites and nonvolatile trichothecenes produced by isolates of <Emphasis Type="Italic">Stachybotrys,Fusarium, Trichoderma,Trichothecium</Emphasis> and <Emphasis Type="Italic">Memnoniella</Emphasis>

We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.     

Observations on the influence of water and soil pH on the persistence of insecticides

Abstract

The pH‐disappearance rate profiles were determined at ca. 25°C for 24 insecticides at 4 or 5 pH values over the range 4.5 to 8.0 in sterile phosphate buffers prepared in water‐ethanol (99: 1 v/v). Half‐lives measured at pH 8 were generally smaller than at lower pH values. Changes in half lives between pH 8.0 and 4.5 were largest (>1000x) for the aryl carbamates, carbofuran and carbaryl, the oxime carbamate, oxamyl, and the organophosphorus insecticide, trichlorfon. In contrast, half lives of phorate, terbufos, heptachlor, fensulfothion and aldicarb were affected only slightly by pH changes. Under the experimental conditions described half lives at pH8 varied from 1–2 days for trichlorfon and oxamyl to >1 year for fensulfothion and cyper‐methrin. Insecticide persistence on alumina (acid, neutral and basic), mineral soils amended with aluminum sulfate or calcium hydroxide to different pH values and four natural soils of different pH was examined. No correlation was observed between the measured pH of these solids and the rate of disappearance of selected insecticides applied to them. These observations demonstrate the difficulty of extrapolating the pH dependent disappearance behaviour observed in homogeneous solution to partially solid heterogeneous systems such as soil.     

The chemical stability of formulations of some hydrolyzable insecticides in aqueous mixtures with hydrolysis catalysts

Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

Knowledge transfer initiative between molecular biologists and environmental researchers and regulators

A Natural Environment Research Council (NERC) funded Knowledge Transfer (KT) workshop was held in the United Kingdom (UK) to identify the needs and opportunities in the application of molecular biology and ‘omics’ techniques to environmental monitoring and risk assessment. Attendees highlighted a lack of effective communication between end-users and researchers as well as difficulties with data interpretation as reasons behind the slow uptake of molecular biology and omics techniques. A number of promising areas in which new techniques could be implemented at a practical level in the very near future were identified, thereby raising the profile of these recent technologies and providing vital proof of concept work. Molecular taxonomy, bacterial source tracking and pre-screening of chemicals for potential toxicities were all viewed as areas in which omics and molecular techniques could have immediate value, with the aim of reducing cost, increasing efficiency and providing more comprehensive data of improved quality.