利用成组生物测试评估某城市典型污水处理工艺

设计了一组基于生物标记物的生物测试方法,并用于评价某城市4个典型污水处理工艺对水中痕量有毒有机物的去除效果.测试方法包括检测芳烃(Ah)受体效应物质生物毒性的EROD(7-乙氧基-3-异吩噁唑酮-脱乙基酶)试验、类雌激素效应物质的重组基因酵母生物毒性试验和遗传毒性物质的SOS/umu试验.结果表明,4个典型的城市污水处理工艺对Ah受体效应物质、类雌激素效应物质和遗传毒性物质都有一定的去除效果,其中A2/O处理工艺对3类物质的去除效果最明显;空气曝气活性污泥工艺对直接遗传毒性物质的去除效果较好,但对Ah受体效应物质的去除效果一般,倒置A2/O处理工艺和氧化沟处理工艺也能够较好地去除这3类物质,两种处理工艺效果相当.采用成组生物标记物方法可以对城市污水中的痕量有毒有机物进行毒性筛选或测试,适用于水处理工艺的风险评价.     

用SOS/Umu生物测试评价北方某自来水厂对遗传毒性物质的去除效果

大量研究表明,饮用水中存在着能导致遗传毒性的物质,在我国许多水厂水质检测能力有限的前提下,生物毒性指标作为反映有毒物质综合指标具有重要的现实意义.本研究应用SOS/Umu生物毒性测试评价了北方某市一自来水厂的A、B、C、D 4套试验工艺在不同的季节(冬春两季)各工艺段出水的遗传毒性效应.结果显示,冬春两季地表水加氯后遗传毒性效应均显著增加,冬季间接遗传毒性效应高于春季;活性炭吸附对去除遗传毒性物质效果显著,但后期加氯使遗传毒性效应增加;冬春两季比较,以及地下水和地表水比较,各工艺出水的遗传毒性效应差别很大.通过研究表明,本研究所应用的生物毒性测试SOS/Umu能够快速、准确地对水厂工艺过程中致突变物质的处理效果进行评价,能对工艺改进提出指导,是自来水质安全性评价的重要补充手段.     

有毒物质事故泄漏对河流污染的数学模拟

通过对有毒物质事故泄漏行为的数学模拟分析，提出了一种计算有毒物质河流断面超标风险率的方法，并通过实例模拟分析，探讨了在一定条件下，即为确保饮用水质的安全，把超标风险率控制在一定范围内，应采取的措施。     

有毒有机物饮用水源的水质标准评述

根据国内外有关水质标准，就适用于饮用水水源中40种有毒有机化合物（包括13种农药）的最大容许浓度作了评述，并对我国现行地表水环境质量标准中所列出的有毒有机化学物质特定项目作了讨论。     

多氯联苯醚类化合物污染研究进展

综述了当前国际上多氯联苯醚的研究现状,详细论述了环境中多氯联苯醚的来源、毒性效应、污染状况、迁移转化和生物富集规律以及多氯联苯醚形成机制.我国关于多氯联苯醚类污染物的研究相对滞后,当前开展适合我国国情的多氯联苯醚物质的环境水平、生态安全与毒理学研究十分必要.     

生态工业仿真系统经济增长与环境压力关系动态变化分析

运用系统动力学模型和结构分解分析模型,对2005—2020年南通经济技术开发区生态工业仿真系统进行经济增长与环境压力关系的时序变化分析,通过基于物质消耗和污染物排放表征的环境压力的影响程度分析,得出:(1)开发区实施生态工业战略后,由2种驱动因素产生的环境压力一直存在,但环境压力在后期都呈现了较快下降趋势。(2)由物质消耗类型影响产生的环境压力,最大的是劳动力投入因子类型,其次为水耗,后期能耗作用超过水耗因子;由污染物排放产生的环境压力主要为固体废物类型所致,COD产生的环境压力稍大于SO2。(3)土地因素对环境压力正效应的变化影响呈下降趋势,经济因素对环境压力增长有明显的正向效应,而且一直是开发区的主导增长因素,技术因素对环境压力的抑制效应在后期减弱;3种因素对环境压力的影响程度视污染物及物质消耗类型不同而有所差异。     

毒性与结构数据库简介

美国国家职业安全与卫生研究所编制发行的RTECS磁带全称为有毒化学物质的登记(Registry of Toxic Effect of ChemicalSubstance).它是从世界科学文献中摘录的化学物质毒性数据,其中共收录了六千多种化学物质的已知毒性效应和生物效应的     

城市污水石灰法深度处理工艺中有毒物质的变化规律

分别采用7-乙氧基异酚恶唑酮-脱乙基酶(EROD)活性测定法,重组人激素受体基因的酵母测试和Q67发光菌试验方法,对北京市某生活污水处理厂的进水、二沉出水以及经过石灰法深度处理后的出水中的类二恶英物质、类雌激素物质和急性毒性物质进行了分析.进水中的三类生物毒性效应物质中的急性毒性物质,可通过活性污泥法基本去除,而对类雌激素物质和类二恶英物质的去除率分别为76%和52%.经过石灰沉淀法的深度处理后,可使上述两类物质的总去除率达到95%和68%.出水中的雌激素当量水平与欧洲国家污水处理厂出水水平相当,而类二恶英物质的总浓度低于美国EPA饮用水中二恶英的最大允许浓度.展示了生物毒性测试方法在排水生态风险和工艺评价方面的应用潜力.     

热解吸技术用以清除有毒沉积物

根据麻省补救技术公司报道,一项热解吸专利技术可用以清除有毒沉积物质。该技术通过高温处理除去沉积物中的有机毒物,这些毒物可被再利用,也可被销毁。该技术的项目负责人Geoffrey Swett说,在德州的Arthur港的一家炼油厂使用该技术不仅处理了有毒废物而未产生空气污染,且降低了45％的炼     

城市污水石灰法深度处理工艺中有毒物质的变化规律

分别采用7-乙氧基异酚恶唑酮．脱乙基酶（EROD）活性测定法，重组人激素受体基因的酵母测试和Q67发光菌试验方法，对北京市某生活污水处理厂的进水、二沉出水以及经过石灰法深度处理后的出水中的类二恶英物质、类雌激素物质和急性毒性物质进行了分析。进水中的三类生物毒性效应物质中的急性毒性物质，可通过活性污泥法基本去除，而对类雌激素物质和类二恶英物质的去除率分别为76％和52％。经过石灰沉淀法的深度处理后，可使上述两类物质的总去除率达到95％和68％。出水中的雌激素当量水平与欧洲国家污水处理厂出水水平相当，而类二恶英物质的总浓度低于美国EPA饮用水中二恶英的最大允许浓度。展示了生物毒性测试方法在排水生态风险和工艺评价方面的应用潜力。     

Challenges in assessing the toxic effects of polycyclic aromatic hydrocarbons to marine organisms: a case study on the acute toxicity of pyrene to the European seabass (Dicentrarchus labrax L.)

The acute toxicity (96 h) of pyrene (PY) to European seabass (Dicentrachus labrax) juveniles assessed in a semi-static bioassay (SSB) with medium renewal at each 12 h, and in a static bioassay (SB) without medium renewal was compared in laboratorial conditions (water PY concentrations: 0.07-10 mg L⁻¹). Main findings in the SSB that assessed mainly the toxicity of PY and its metabolites were: increased levels of bile PY metabolites in good agreement with the profile of lipid peroxidation levels (LPO) in exposed fish relating PY exposure and oxidative damage; increased levels of PY-type compounds in the brain indicating their ability to cross the blood-brain barrier; increased levels of these substances in liver and muscle which are edible tissues for humans thus raising concern on potential adverse effects on consumers of fish from PY contaminated areas; a significant inhibition of glutathione S-transferase activity suggesting its involvement in PY detoxication as toxicant scavenger; finally, an almost complete impairment of the swimming velocity at all the PY concentrations linking sub-individual to higher population level effects. In the SB, where the overall toxicity of PY, its metabolites and environmental degradation products was evaluated, 19% and 79% of PY decay in test media was found at 12 and 96 h, respectively. In general, the effects were similar to those of SSB but with significant effects being induced at higher PY concentrations indicating that the parental compound is more toxic than its environmental degradation products. The other main differences relatively to the SSB were: increased levels of PY-type substances in the liver suggesting more accumulation in this organ. Therefore, these findings highlight the need of carefully considering experimental design options when assessing the toxicity of readily degradable substances to marine fish, and stress the importance of taking into consideration the toxicity of environmental degradation products in addition to toxic effects of the parental substance and its metabolites for marine ecological risk assessment.     

Effect-Directed Analysis of Key Toxicants in European River Basins. A Review (9 pp)

Background, Aim and Scope Extensive monitoring programs on chemical contamination are run in many European river basins. With respect to the implementation of the European Union (EU) Water Framework Directive (WFD), these programs are increasingly accompanied by monitoring the ecological status of the river basins. Assuming an impact of chemical contamination on the ecological status, the assignment of effects in aquatic ecosystems to those stressors that cause the effects is a prerequisite for taking political or technical measures to achieve the goals of the WFD. Thus, one focus of present European research is on toxicant identification in European river basins in order to allow for a reduction of toxic pressure on aquatic ecosystems according to the WFD. Main Features: An overview is presented on studies that were performed to link chemical pollution in European river basins to measurable ecotoxic effects. This includes correlation-based approaches as well as investigations that apply effect-directed analysis (EDA) integrating toxicity testing, fractionation and non-target chemical analysis. Effect-based key toxicants that were identified in European surface waters are compiled and compared to EU priority pollutants. Further needs for research are identified. Results: Studies on the identification of effect-based key toxicants focused on mutagenicity, aryl hydrocarbon receptor-mediated effects, endocrine disruption, green algae, and invertebrates. The identified pollutants include priority pollutants and other well-known environmental pollutants such as polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins, furans, and biphenyls, nonylphenol, some pesticides and tributyltin, but also other compounds that were neither considered as environmental pollutants before nor regulated such as substituted phenols, natural or synthetic estrogens and androgens, dinaphthofurans, 2-(2-naphthalenyl)benzothiophene, and N-phenyl-2-naphthylamine. Discussion: Individual studies at specific sites in a European river basin demonstrated the power of combined biological and chemical analytical approaches and, particularly, of effect-directed analysis. However, the available information on effect-based key toxicants is very limited with respect to the entirety of rivers possibly at risk due to chemical contamination and with respect to toxicological endpoints considered at a specific site. A relatively broad basis of information exists only for estrogenicity and aryl hydrocarbon, receptor-mediated effects. Conclusions: The development of tools and strategies for an identification of key toxicants on a broader scale are a challenging task for the next years. Since investigations dealing with toxicant identification are too labor and cost-intensive for monitoring purposes, they have to be focused on the key sites in a river basin. These should include hot spots of contamination, particularly if there is evidence that they might pose a risk for downstream areas, but may also involve accumulation zones in the lower reach of a river in order to get an integrated picture on the contamination of the basin. Perspectives: While EDA is almost exclusively based on measurable effects in in vitro and in vivo biotests to date, an increasing focus in the future should be on the integration of EDA into Ecological Risk Assessment and on the development of tools to confirm EDA-determined key toxicants as stressors in populations, communities and ecosystems. Considering these requirements and applied in a focused way, toxicant identification may significantly help to implement the Water Framework Directive by providing evidence on the main stressors and possible mitigation measures in order to improve the ecological status of a river ecosystem.     

Assessment of toxicant activity in sediments by the ECHA biocide monitor

The ECHA Biocide Monitor, a dipstick procedure originally designed to test the effectiveness of in situ biocides, was evaluated as a possible environmental toxicity assessment procedure. The dipstick procedure was applied to 94 sediment extracts which were also tested by three well documented toxicant screening procedures; Microtox, Daphnia magna and Spirillum volutans. In these samples the Daphnia magna test proved to be the most sensitive indication of toxicant activity (63 of 94) with the ECHA Biocide Monitor easily being the second most sensitive procedure with 27 of 94 sediments indicating the presence of toxic substances. Results of the investigation are detailed.     

Testing toxicity of volatile substances with algae

A modification of the AAPBT (USEPA) for toxicity batch tests on volatile substances is described. The procedure permits maintenance of a constant concentration of toxicant in the culture and calculation of the concentration in the culture medium at the equilibrium, on the basis of physical characteristics of the chemical. The results of the application of the method on five chlorobenzenes are reported and compared with literature data.     

Effects of the antibiotics oxytetracycline and tylosin on soil fauna

Antibiotics may enter the terrestrial environment when amending soils with manure. A Note of Guidance on ecological risk assessment of veterinary medicines was issued in January 1998. Hardly any information about ecotoxicological effects of already existing substances are available. This study has tested the effects of two widely used antibiotics, tylosin and oxytetracycline, on three species of soil fauna: Earthworms, springtails and enchytraeids. Neither of the substances had any effect at environmentally relevant concentrations. The lowest observed effect concentration was 3000 mg kg-1 and in many cases no effect was seen even at the highest test concentration of 5000 mg kg-1.     

Hazard prioritization in ecological risk assessment through spatial analysis of toxicant gradients

The analysis of spatial relationships among the distribution of environmental stressors and observed or predicted adverse effects may be a useful method of prioritizing hazards in regional ecological risk assessment (ERA). Geographic information systems were used to compare the spatial distribution of toxicant concentrations in sediments of Chesapeake Bay with the distribution of areas in the basin where ecological impacts have historically been observed. Toxicants were then prioritized based upon the strength of their spatial association with the high impact areas. This method of hazard identification/prioritization was validated against the Chesapeake Bay Program's lists of toxics of concern and toxics of potential concern (TOC and TOPC, respectively). Of the 18 toxicants on the TOC/TOPC lists that were considered in the current study, 15 (83%) were identified as priority contaminants in the current study, 11 (73%) of which were either of primary or secondary concern. The use of spatial analysis tools in ERA may lead to more rapid and rigorous methods for prioritizing environmental risks.     

Perfluorinated and chlorinated pollutants as predictors of demographic parameters in an endangered seabird

Despite global occurrence of several perfluorinated compounds (PFCs) the potential ecological effects of such substances on natural populations are not known. In endangered lesser black-backed gulls (Larus fuscus fuscus) on the Norwegian Coast, the blood concentrations of PFCs were as high as legacy organochlorines (OCs), and here we examined whether PFCs show associations similar to those of OCs to factors potentially affecting population growth, by evaluating relationships between contaminant concentrations and demographic parameters (reproductive performance and the probability of adults returning between breeding seasons). PFCs were not adversely associated with demographic parameters, while the most persistent OCs; notably PCB and p,p′-DDE, were adversely associated with early chick survival, and adult return rate. This study thus suggests that when the concentrations of PFCs and OCs are of similar magnitude in a gull population, OCs are more likely to cause adverse ecological effects.     

Evaluation of effluent toxicity and ambient toxicity in a polluted lowland river

The impact of an industrial effluent containing high loads of calcium, cadmium, lead chloride and sulphate, on a river ecosystem was assessed using a combination of an effluent toxicity test, an ambient toxicity test and an ecological survey. Only this combination of techniques made it possible to discriminate between the effects of the discharge and those of the background pollution. Each of the individual techniques detected essential effects which the other failed to reveal. With the physical and chemical measurements, important increases of several components were measured at all sampling sites downstream of the discharge. With the ecological survey, however, no large changes in water quality could be determined at the sampling sites, due to the high degree of pollution present upstream of the discharge. Reproduction of Daphnia magna, exposed to sublethal effluent dilutions, was followed over two generations. The offspring of the first generation were shown to have an increased sensitivity to the effluent, compared to the first generation that was born from previously unexposed mothers. Besides the toxicity of the effluent, the acute and chronic toxicity of its main component, CaCl(2), was also determined. The results of the CaCl(2)-tests and toxicity data from literature for the suspected toxicants were transformed to Toxic Units (TU). Using the sum of the TUs we investigated the possibility of predicting effluent toxicity to Daphnia magna. Effluent toxicity was under-estimated by calculating the sum of the TUs of the individual components. Dilution of the effluent to a level at which the measured toxicant concentrations comply with European regulations still showed significant effects on Daphnia reproduction.     

Microbial conversion of fungicide vinclozolin

An ecological safety study of using vinclozolin in field and laboratory experiments showed that the effect of the preparation led to a decrease in the abundance of actinomycetes and mycelial fungi and an enhancement of nitrification. The residual amounts of vinclozolin in soil after 12 months were 6-12% of the dose introduced. The persistent chlorinated derivatives of the toxicant were found. Microbial strains pertaining to the genera Pseudomonas and Bacillus were isolated that utilized vinclozolin as the sole source of carbon and energy.