生态立乡、旅游兴乡、创建省级生态乡

乐清市城北乡地处乐清市北部山区，东连北雁荡山，西邻中雁荡山，南距乐清市区6．4 km，北接永嘉楠溪江，乡域面积42．7 km2，平均海拔449m，辖17个行政村，总人口11086人。2005年，全乡国内生产总值3．12亿元，工业总产值3亿元，农业总产值0．2亿元，农民人均收入3151元。城北乡处处山青水秀，景色宜人，气候温和，特产繁多，是游览、避暑、休养的佳境，素有乐清市的“后花园”之称，有着丰富的自然和人文资源。境内有温州市级风景名胜区灵山景区，因其生态环境和谐优美，2004年底被张纪中导演的《神雕侠侣》摄制组选为外景地。近几年，城…     

浅层地下水遥感找水模型研究

采用遥感-数据-模型相融合的方法，建立了浅层地下水推断模型。该模型克服了以往勘察方法费用高、效率低、周期长的不足，从未知出发，由面到点，层次分明，衔接有序。经实地考察验证，该模型精度较准，效率较高，具有实用性，不仅可以宏观、快速、高效地确定浅层地下水的分布和范围，而且可以降低费用，缩短周期，起到事半功倍的作用，为进一步找水工程的布置提供依据，确定找水方向，避免找水的盲目性。     

SBR法的特点及其在生物脱氮中的应用

SBR兼有全混合反应器与推流式反应器的优点，物料混合均匀，耐冲击负荷，不存在物料返混，生化反应动力大，处理好，SBR法的整个过程可放置于一个构筑物内完成，工艺简单，操作灵活，此外，通过对SBR的适当调控，易形成好氧／缺氧交替的环境，为生物脱氮创造条件，近年来，SBR法得到了较大的发展，操作方式也得很大的改进。     

燃煤倒焰窑烟尘污染的治理

燃煤倒焰窑烟尘治理，因其本身结构特点，若单纯采用末端治理，则投资大，治理效果不稳定，在治理上存在一定难度。通过实践，采用炉头增氧，尾部喷淋的治理工艺可以达到好的治理效果，而且投资少，工期短，运行费用低，易于操作。     

土壤中四氯苯、六氯苯的测定

通过实验测定土壤中四氯苯、六氯苯的有机污染组分，详细介绍了样品的提取、净化与分析。该方法在0～150ug／L范围内，线性良好，其检出限分别是1，2，3，5四氯苯为1．2ug／kg，1，2，4，5四氯苯为2．0ug／kg，1，2，3，4四氯苯为2．0ug／kg，六氯苯为0．6ug／kg。     

山东培育出富油海洋微藻

国家驻山东科研单位培育出富油海洋微藻，最高含油比已达68％，并在此基础上，制取生物柴油，与初步实现产业化的玉米等粮食作物制取生物柴油的方法比较，海洋微藻的产量高，单位面积的产量是粮食的几十倍，生长周期短、繁殖快，不占用耕地。同时，微藻个体小、木素含量很低，易粉碎干燥，用微藻生产液体燃料，加工要求相对较低，生产成本较低。此外，微藻生长可消耗大量二氧化碳，从微藻到油的生产全过程，可以实现零排放，具有良好的环境效益。     

关于砖瓦业发展与污染防治对策思考

1．砖瓦业的发展状况及污染现状随着我国改革开放的不断深入，经济建设得到快速发展，城乡建设突飞猛进，伴随建筑业的兴起，城市基本建设和农村私人建房的不断增多，建筑材料需求量与日俱增，出现了砖瓦业盲目发展的势头，带来了许多迫切需要解决的环境问题。目前，砖瓦业多数分布于乡镇农村。以浙江省富阳市为例，全市现有红砖窑Zoo余只，村、个体办184只，占92％，其中轮窑3O只，占15％，小土窑（吊线窑）17O只，占85％。砖窑分布带有区域群布性，富阳、新登、三山、常安、高桥等5个镇，已建有红砖窑15O余只，占富阳市总窑数的75％左右…     

稀土系列催化剂对焦化废水的催化湿式氧化

以稀土元素Ce制得催化剂系列，在高温，高压条件下对焦化废水进行催化湿式氧化研究，考察载体，焙烧温度，活性组分的配比对催化剂的催化活性的影响，以及反应温度，氧气分压，反应时间和催化剂用量对氧化过程的影响，设计正交实验确定最佳的工艺参数：反应温度为240℃，氧气分压3.0MPa，催化剂用量30g/L，此时废水的COD法除率达到90％以上。     

射流曝气器研究进展

射流曝气技术的应用与完善，有赖于射流曝气器的研制与发展，本文综述了射流曝气器的研究进展，并根据供气方式，工作压力，结构类型，安装方式，安装高度进行了分类，其中着重详述了对研发射流器比较重要的结构类型，最后指出射流曝气的研究趋势。     

生物秸秆分解技术获突破

内蒙古自治区兴安盟农牧业高新技术研究所所长、国家科技进步特等奖获得者王善堂，依据作物秸秆形成生化反应的逆反应原理，用生物复合酶和载体协同作用，将秸秆大分子分解为小分子，直至降解为氨基酸和葡萄糖，从而被动物直接吸收。在该过程中，不仅纤维素、细胞壁、细胞间质分解为营养物，同时，细胞壁被破坏，细胞内营养释放，从而使秸秆饲料转化率大大提高。经分解后的秸秆饲料，不仅为牛羊等食草动物充分吸收，而且，为猪、鸡等食粮动物充分消化。这种只需加入酶催化活化分解剂，秸秆在常温下，经2h生化反应就能制成高营养的秸秆饲料，被专家高度评价，认为该技术具有突破性，     

Non-controlled biogenic emissions to the atmosphere from Lazareto landfill, Tenerife, Canary Islands

GOAL, SCOPE AND BACKGROUND: [corrected] Historically, landfills have been the simplest form of eliminating urban solid waste with the minimum cost. They have been the most usual method for discarding solid waste. However, landfills are considered authentic biochemical reactors that introduce large amounts of contaminants into the environment in the form of gas and leachates. The dynamics of generation and the movement of gas in landfills depend on the input and output parameters, as well as on the structure of the landfill and the kind of waste. The input parameters include water introduced through natural or artificial processes, the characteristics of the urban solid waste, and the input of atmospheric air. The main output parameters for these biochemical reactors include the gases and the leachates that are potentially pollutants for the environment. Control systems are designed and installed to minimize the impact on the environment. However, these systems are not perfect and a significant amount of landfill gas could be released to the atmosphere through the surface in a diffuse form, also known as Non-controlled emission. In this paper, the results of the Non-controlled biogenic gas emissions from the Lazareto landfill in Tenerife, Canary Islands, are presented. The purpose of this study was to evaluate the concentration of CH4 and CO2 in the soil gas of the landfill cover, the CH4 and CO2 efflux from the surface of the landfill and, finally, to compare these parameters with other similar landfills. In this way, a better understanding of the process that controls biogenic gas emissions in landfills is expected. METHODS: A Non-controlled biogenic gas emission survey of 281 sampling sites was carried out during February and March, 2002. The sampling sites were selected in order to obtain a well-distributed sampling grid. Surface landfill CO2 efflux measurements were carried out at each sampling site on the surface landfill together with soil gas collection and ground temperatures at a depth of 30-40 cm.The CH4 efflux was computed from CO2 efflux and from the ratio CH4/CO2 in the soil gas. Soil gas samples were collected at a depth of 30-40 cm using a metallic probe and 20 cc hypodermic syringes, and later stored in evacuated 10 cc vacutainers for laboratory analysis of bulk composition. The gas sample was introduced in a vacutainer filled with deionized water and displacing the water until the vacutainer was filled with the gas sample in order to avoid air contamination from entering. The surface landfill temperature of the landfill was measured at a depth of 40 cm using a digital thermometer type OMEGA 871A. Landfill gases, CO2 and CH4, were analyzed within 24 hours using a double channel VARIAN micro-GC QUAD CP-2002P, with a 10 meter PORAPLOT-Q column, a TCD detector, and He as a carrier gas. The analysis temperature was 40 degrees C and the injection time was 10 msec. Surface landfill CO2 efflux measurements were performed using a portable NDIR spectrophotometer Licor-800 according to the accumulation chamber method (Chiodini et al. 1996). The data treatment, aimed at drawing the flux map and computing the total gas output, was based on the application of stochastic simulation algorithms provided by the GSLIB program (Deutsch and Journel 1998). RESULTS: Diffuse CH4 and CO2 efflux values range from negligible values up to 7,148 and 30,573 g m(-2) d(-1), respectively. The spatial distribution of the concentration and efflux of CO2, CH4 and soil temperature, show three areas of maximum activity in the landfill, suggesting a non-uniform pattern of diffuse degassing. This correlation between high emissions and concentration of CO2, CH4 and soil temperatures suggests that the areas of higher microbial activity and exothermic reactions are releasing CO2 and CH4 to the atmosphere from the landfill. Taking into consideration the spatial distribution of the CO2 and CH4 efflux values as well as the extension of the landfill, the Non-controlled emission of CO2 and CH4 to the atmosphere by the Lazareto's landfill are of 167 +/- 13.3 and 16 +/- 2.5 t d(-1), respectively. DISCUSSION: The patterns of gas flow within the landfill seem to be affected by boundary materials at the sides. The basalt layers have a low permeability and the gas flow in these areas is extensive. In this area, where a basalt layer does not exist, the flow gas diffuses toward the sea and the flux emissions at the landfill surface are lower. This behavior reflects the possible dissolution of gases into water and the deflection of gases towards the surface at the basalt boundary. The proximity to the sea, the installation of a palm tree garden and, as a result, the contribution of water coming from the watering of this garden has reactivated the system. The introduction of sea water into the landfill and the type of boundary could be defining the superficial gas discharges. CONCLUSIONS: Results from this study indicate that the spatial distribution of Non-controlled emission of CO2 and CH4 at the Lazareto's landfill shows a non-uniform pattern of diffuse degassing. The northeast, central and northwest areas of the Lazareto's landfill are the three areas of high emissions and concentration of CO2 and CH4, and high temperatures. The correlation between high emissions and the concentration of CO2, CH4, and the high temperatures suggest that the areas of higher microbial activity and exothermic reactions are releasing more CO2 and CH4 to the atmosphere from the landfill. A high concentration of CO2 is probably due to the presence of methanotrophic bacteria in the soil atmosphere of the landfill. Patterns of gas flow within the landfill seem to be affected by boundary materials (basalt layers) of low permeability, and side boundaries of the flux emissions at the surface are higher. At the sides of seawater and sediment boundaries, flux emissions at the landfill surface are lower. This behavior reflects a possible dissolution of gases into the water and the deflection of gases towards the surface at the basalt boundary. With this study, we can compare the data obtained in this landfill with other landfills and observe the different levels of emission. The proximity to the sea and the installation of the palm tree garden palms and, as a result, the contribution of water coming from the watering of this garden has reactivated the system. Many landfills worldwide located in similar settings could experience similar gas production processes. RECOMMENDATIONS AND PERSPECTIVES: The need for investigating and monitoring sea water and sediment quality in these landfills is advisable. Concentrations and fluxes of contaminants and their impact in the area should be assessed. With this study we can compare the data obtained in these landfills with other landfills and observe the different levels of emission.     

Irradiation of sorbents by ions of polymorphic metals for modeling <Superscript>90</Superscript>strontium sedimentation

Background, Aims and Scope Advances in radioecology can support improvements in environmental remediation technologies, especially by illuminating interaction processes between polymorphic metal radionuclides and various materials and their ions in aqueous solutions. This study modeled interaction processes of ⁹⁰Sr with transitive metals to delineate the behavior of polymorphic metal radionuclides. Experimental and modeling results confirmed Sr sedimentation was sensitive to the physical impact of radionuclides on various sorbents and possible chemical reactions occurring between the radionuclides and sorbents. Methods Models were developed to simulate ⁹⁰Sr sedimentation process, and the potential physical and chemical reactions accompanying the process. Models were verified, inorganic salts were used as sorbents to absorb metal cations, activity levels were recorded before and after mixing the inorganic salts while the efficiency of sedimentation using the heavy metals composites was quantified. Results and Discussion This research demonstrates that the process of the sedimentation is complex and occurs in several stages. Micro-structural analysis shows that zones of interaction between the sorbent and source metal are formed during the irradiation of the target’s metal surface. Electrical-microscopic analysis indicates that the composition of the formed zones of interaction of Ti (Sr) with target metals has various structures. Roentgenophase analysis indicates that the interaction of the ions of a precipitable source and a target occurs according to constitution diagrams of equilibrium systems. The results indicate that application of inorganic salts composites based on modeling increases the efficiency of the deactivation of aqueous solutions when compared to standard aluminum sulfate composite. Conclusions Experimental and modeling results confirm ⁹⁰Sr sedimentation is sensitive to the physical impact of radionuclides on various sorbents and possible chemical reactions occurring between the radionuclides and sorbents. The models support estimation of the physical impact of polymorphic metal radionuclides on various components of sorbents and possible chemical reactions occurring between the radionuclides and sorbents during the interaction. Inorganic salt composites deactivate and clear ⁹⁰Sr and Sr⁺² from water. This paper is openly accessible!     

Impact of spiked concentrations of Cd,Pb, As and Zn in growth medium on elemental uptake of Nasturtium officinale (Watercress)

This study is aimed at investigating the impact of water quality on the uptake and distribution of three non-essential and toxic elements, namely, As, Cd and Pb in the watercress plant to assess for metal toxicity. The plant was hydroponically cultivated under greenhouse conditions, with the growth medium being spiked with varying concentrations of As, Cd and Pb. Plants that were harvested weekly for elemental analysis showed physiological and morphological symptoms of toxicity on exposure to high concentrations of Cd and Pb. Plants exposed to high concentrations of As did not survive and the threshold for As uptake in watercress was established at 5 ppm. Translocation factors were low in all cases as the toxic elements accumulated more in the roots of the plant than the edible leaves. The impact of Zn on the uptake of toxic elements was also evaluated and Zn was found to have an antagonistic effect on uptake of both Cd and Pb with no notable effect on uptake of As. The findings indicate that phytotoxicity or death of the watercress plant would prevent it from being a route of human exposure to high concentrations of As, Cd and Pb in the environment.     

Modelling radionuclide distribution and transport in the environment

Mathematical models of radionuclide distribution and transport in the environment have been developed to assess the impact on people of routine and accidental releases of radioactivity from a variety of nuclear activities, including: weapons development, production, and testing; power production; and waste disposal. The models are used to estimate human exposures and doses in situations where measurements have not been made or would be impossible or impractical to make. Model results are used to assess whether nuclear facilities are operated in compliance with regulatory requirements, to determine the need for remediation of contaminated sites, to estimate the effects on human health of past releases, and to predict the potential effects of accidental releases or new facilities. This paper describes the various applications and types of models currently used to represent the distribution and transport of radionuclides in the terrestrial and aquatic environments, as well as integrated global models for selected radionuclides and special issues in the fields of solid radioactive waste disposal and dose reconstruction. Particular emphasis is placed on the issue of improving confidence in the model results, including the importance of uncertainty analysis and of model verification and validation.     

Analysis of Mosses and Soils for Quantifying Heavy Metal Concentrations in Sicily: A Multivariate and Spatial Analytical Approach

- DOI: http://dx.doi.org/10.1065/espr2006.01.006 Background The use of vegetal organisms as indicators of contamination of the environment is partially replacing traditional monitoring techniques. Amongst the vegetal organisms available, mosses appear to be good bioindicators and are used for monitoring anthropogenic and natural fall-out on soils. This study has two objectives: the evaluation of the concentrations of heavy metals in soils and mosses of the Sicily Region, in Italy and the identification of the origin of fall-out of heavy metals. Methods Mosses and the surface soil were sampled at 28 sites, only the youngest segments of Hylocomium splendens and Hypnum cupressiforme, corresponding to the plant tissues produced during the last 3 years, were taken. The elements Cd, Cu, Ni, Pb and Zn were analysed by ICP-MS and Hg by AAS. Statistical analysis was by PCA and spatial representation by GIS. Results and Discussion In the mosses sampled in Sicily, the highest concentrations of Cd were found around the cities of Palermo and Messina. The highest concentrations of Hg were recorded in the northern part of the island between Trapani and Messina, similar to the distribution of Cu. Different areas with the highest concentrations of Ni were found near the south coast, in the vicinity of Palermo and around the Volcano Etna. The highest concentrations of Pb were found in the south-west coast near Agrigento, where important chemical plants and petroleum refineries are located. Except for a few locations, Zn fall-out was found to be evenly distributed throughout Sicily. Conclusion The sites where the concentrations of heavy metals cause greatest concern have been revealed by the PCA analysis and portrayed using GIS. Also of some concern is the diffuse and anthropogenic origin of Hg and Cd. The combined approach of using soil and mosses, together with pedological interpretation and application of multivariate statistical techniques has provided valuable insight into the environmental aspects of heavy metal deposition in a region of southern Europe. Recommendations and Outlook Further insight into the deposition of heavy metals will require more detailed sampling of soils and mosses in both new and previous study areas. This needs to be complemented by detailed pedological investigations in the study areas. Future research programmes will address these issues.     

Formation of aromatic chlorinated compounds catalyzed by copper and iron

This study shows the catalyzing effects of iron and copper on the formation of chlorinated compounds such as chlorobenzenes (ClBzs), chlorophenols (CIPhs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Both total concentrations and congener distributions have been studied. The parameters and conditions varied during the combustion tests were the complete and incomplete combustion and the metal and chlorine addition. The incomplete combustion promoted the formation of organic chlorinated compounds in flue gas particles. Highly chlorinated congeners of PCDD/F were dominant in the flue gas particles, whereas the importance of lower chlorinated congener were increased in the gas phase. In the complete combustion conditions the concentrations of PCDD/Fs increased when the degree of chlorination were high, nevertheless the concentrations of tetra and penta PCDD/Fs were higher in the gas phase than the concentrations in the fly ash particles. Organic chlorine promoted the formation of chlorinated compounds more effectively than inorganic chlorine, which instead promoted the formation of PCDD/Fs in the gas phase, especially with copper catalyst. Different concentration levels of chlorinated compounds were observed in the gas phase and in particles when the chlorine source and combustion conditions were varied from incomplete to optimum conditions. Both copper and iron seem to have a catalytic effect on PCDD/F formation.     

Development of continental scale multimedia contaminant fate models: integrating GIS

The incentives and approaches for modelling chemical fate at a continental scale are discussed and reviewed. It is suggested that a multi-media model consisting of some 20-30 regions, each of which contains typically seven environmental compartments represents a reasonable compromise between the issues of the need for detailed resolution, avoidance of excessive data demands and inherent complexity and transparency. Strategies adopted in compiling the Berkley-Trent (BETR) model for North America are discussed and used to illustrate the issues of selecting appropriate number and nature of segments, treatment of air and water flows and the acquisition of environmental data. It is suggested that GIS software can play a valuable role in gathering and processing such data and in the display and interpretation of the results of the model assessment. The BETR model will be a useful tool for describing the nature of persistence and long-range transport of chemicals of concern in the North American environment.     

预涂动态膜强化渗透与截留性能研究

以二氧化钛粉体材料为涂膜剂,陶瓷管为基膜制备预涂动态膜,引入通量增强系数Zi和截留增强系数Fi研究了预涂动态膜制备条件对其强化渗透与截留性能的影响,并用SEM电镜对预涂动态膜和基膜表面形貌进行表征。结果表明:制备的预涂动态膜表面均匀密实,其孔径低于基膜平均孔径。预涂动态膜的渗透与截留性能随涂膜液pH值的增加而增加,在跨膜压差低于0.2 MPa、错流速度低于1.5 m/s,涂膜时间少于30 m in和涂膜液浓度低于0.4 g/L范围内,提高这些参数值有利于提高预涂动态膜的渗透与截留性能,超出此范围时,提高这些参数值对增强其渗透与截留性能的效果已不明显,其中错流速度的影响相对小些。跨膜压差为0.2 MPa,错流速度为1.5 m/s,涂膜时间30 m in,涂膜液浓度和pH值分别为0.4 g/L和10.2时为最佳制备条件。     

Effects of sediment composition on inorganic mercury partitioning, speciation and bioavailability in oxic surficial sediments

Artificially prepared sediments were used to assess the effects of sediment composition on inorganic Hg partitioning, speciation and bioavailability. Organic coating in sediment greatly increased the Hg partitioning and the amount of bioavailable Hg bound with the clay and the Fe and Mn oxides, but had little effect on that bound with the quartz and calcium carbonate as a result of weaker binding of humic acids and fulvic acids. The clay content increased the concentration of Hg in the sediments but inhibited the gut juice extraction due to the strong binding of Hg-organic matter (OM) complexes. Most Hg in the sediments was complexed by OM (mainly distributed in the organo-complexed phase and the strongly complexed phase), and the Hg-OM complexes (especially Hg in the strongly complexed phase) in sediments contributed much to gut juice extraction. Redistribution of Hg-OM complexes between sediments and gut juices may occur during gut juice extraction and modify Hg bioavailability and speciation in sediments.     

Environmental assessment of ester-based lubricants after application

GOAL, SCOPE AND BACKGROUND: Lubricants based on renewable resources are an environmentally friendly alternative to petrochemical products due to their better ecotoxicological performance and their excellent biodegradability. To improve the technical performance of lubricants, and to reduce friction and wear, the use of additives is nowadays obligatory. The collaborative research center SFB 442 aims at developing environmentally acceptable lubricants that facilitate the avoidance of these additives by transferring their function to suitable coatings. For a complete assessment of the ecological performance of these newly developed lubricants, the whole life cycle including production, application as well as disposal and fate in the environment is studied. In the following study the focus was on the application and its influence on the environmental behavior of the lubricant. The application of lubricants leads, among other things, to the intake of metals due to abrasion from tools, work pieces or mechanical components. Previous examinations indicated a possible influence of metals on the toxicity of eluates prepared from used lubricants (Erlenkaemper et al. 2005). To clarify if the apparent toxicity of used lubricants solely results from the intake of metals, the extractability of these metals from the oil matrix is determined. By combining chemical analyses with bioassays, the bioavailability of metals that are present in the extract is estimated. To further investigate the relevance of metals on toxicity, toxic units (TU) were calculated and related to the results of the bioassays. Interactions between the metals were investigated with aqueous mixtures of metal chlorides and calculations based on the concept of concentration addition and independent action. METHODS: A lubricant mixture was applied to a tribological test bench that simulates real conditions of use and extremely short time load, respectively. Samples were taken at particular times, water soluble fractions (WSF) of these fluids were prepared and dilution series were investigated in several bioassays. Concentration of metals and total organic carbon (TOC) were determined in the eluates. TUs were calculated according to Sprague (1970) and mixture toxicity was calculated according to the concept of concentration addition (Loewe and Muischnek 1926) and independent action (Bliss 1939). RESULTS: Analyses of the metal content of the lubricant and the eluates clearly revealed the availability of the metals in the aqueous extracts. Especially copper, zinc, nickel and chromium were found and their concentrations increased during the time of use. The water extractable fraction, e.g., of copper, rose from 8.8% to 45.3% of the total content in the lubricant after 33.5 hours of use. Tests performed with the algal growth inhibition assay and the luminescence inhibition assay revealed the uptake or absorption by the organisms and, thus, the bioavailability of the metals. The calculation of TUs partly indicated a possible influence of the metals on ecotoxicity of the eluates. Copper reached concentrations equal to or higher than the EC50 value of copper chloride in the growth inhibition assays with algae and Ps. putida as well in the immobilization assay with daphnids. TUs for copper are also larger than 1 for the algal growth inhibition assay. The EL50 values indicated that the luminescence inhibition assay was the most sensitive test system, with values between 4.7% and 9.6%. While the toxicity towards algae and V. fischeri in the growth inhibition assay decreased until both organisms were no longer influenced by the exposure, the EL50 values for the D. magna immobilization assay and the Ps. putida growth inhibition assay decreased with the progressing use of the lubricant. The tested metal salt mixtures showed that Ps. putida, algae and daphnids are the most sensitive organisms with EC50 values below 1 mg/l. DISCUSSION: Although the intake of metals mainly occurred via abrasion of particles, the results revealed the availability of these metals in water. The availability varied for each of the four metals. For both the algal growth inhibition assay and the luminescence inhibition assay, an uptake or absorption of the metals could be demonstrated. The calculated TUs indicated an effect in some bioassays that was not verified in the test itself. The influence of copper on V. fischeri, for example, was not confirmed while the EL50 values for the daphnid bioassay decreased, meaning that the eluates became more toxic with progressing use of the lubricant. The calculations of mixture toxicity based on the concept of concentration addition demonstrated good correlations with the tested metal mixtures, but also a different sensitivity of the organisms. CONCLUSIONS: The results presented here reveal the availability of those metals in water that were taken in during the use of the lubricant in a tribological test bench and, thus, have the possibility of interacting with the organisms. The availability of the metals in the bioassays was proven by chemical analyses. The calculation of TUs and the corresponding EL50 values, however, indicate different availabilities of the metals. The results of the metal salt mixtures show good correlations with calculations of mixture toxicity based on concentration addition. Moreover, the varying sensitivity of the organisms when exposed to eluates or metal mixtures indicates a different bioavailability of the metals and/or the presence of other compounds that exert toxic action. RECOMMENDATIONS AND PERSPECTIVES: For further investigations, the organic oil matrix and its influence on the toxicity have to be taken into account. The toxicity of the eluates may not only be due to metals; additional effects could arise from changes in the lubricant itself.