应用淡水发光细菌测定土壤Cu急性毒性的影响因素研究

在环境污染物的毒性评价和监测中,发光细菌法是一种具有快速、灵敏和廉价等优点的直接生物测试方法。鉴于海水发光细菌在土壤中应用的局限性,本文拟应用淡水发光细菌青海弧菌Q67（Vibrio—qinghaiensis sp．-Q67）进行土壤中Cu的毒性测定,并对其在土壤Cu急性毒性测定的影响因素进行了研究,包括pH对青海弧菌Q67发光的影响,背景溶液的选择及0．01mol·L^-1 CaCl2对毒性测定的影响,以期确定淡水发光细菌测定土壤Cu急性毒性最佳条件。结果表明,青海弧菌Q67可以应用于pH范围在5．5～9．0之间的样品;不同的背景溶液中,青海弧菌Q67在高浓度人工土壤溶液中的发光最稳定,且不同背景溶液对Cu的毒性测定影响差异不显著,因此,推荐高浓度人工土壤溶液作为青海弧菌Q67应用于土壤样品毒性测定的背景溶液;常用的土壤浸提剂0．01mol·L^-1 CaCl2显著降低了Cu的毒性（全Cu表示）。研究结果对青海弧菌Q67毒性测试方法的建立和在土壤中的应用提供了非常重要的依据。     

土壤提取液中汽油的毒性研究

本文利用发光细菌法研究了土壤水提取液中2种汽油(90#和93#)的生物毒性。提取液中90#和93#汽油分别在63.2~90.1mg/L和62.7~91.1 mg/L范围内有较高的生物毒性,并随浓度的升高而增强,90#和93#汽油的土壤水提液EC50值分别为83.5 mg/L和83.7 mg/L,在土壤中的临界值为2308 mg/kg和3678 mg/kg。这些结果为发光细菌毒性测定方法在石油产品污染土壤生物毒性评价中应用提供了可能性。     

二元含Hg(Ⅱ)重金属混合物对发光细菌的联合毒性

本文采用二次二因子回归通用旋转组合实验设计,以明亮发光杆菌(photobacterium phosphoreum)T3变种作为毒性测试物种,研究Hg2 Pb2 、Hg2 Cd2 和Hg2 Cr6 等二元含Hg(Ⅱ)重金属混合物的联合毒性作用和主因子作用,建立了3个相应的数学模犁.结果表明,Hg2 、Pb2 、Cd2 与Cr6 对明亮发光杆菌的毒性有显著的正效应.3个含Hg2 二元重金属混合物对发光细菌的联合毒性作用不同,总体上Hg2 与Pb2 以协同作用为主,Hg2 与Cd2 为相加作用,而Hg2 与Cr6 以拮抗作用为主.从单因子作用效应的角度看,3个混合物中对发光细菌的毒性Hg2 大于另一重金属,即Hg2 为主因子.发光细菌法作为一种快速、操作方便、成本低廉的生物监测方法,将在农产品污染物毒性评价和农产品安全快速检测中有着广泛的应用前景.     

Microtox技术检测多环芳烃生物毒性的研究

利用Microtox技术检测 5种多环芳烃化合物生物毒性结果表明 ,二甲亚砜配制的测试液中萘、菲及荧蒽均对发光细菌具有一定生物毒性 ,且随浓度的增大而增强 ,相同浓度下毒性菲 >萘 ;测试液中当萘浓度小于其溶解度时即产生 10 0 %的抑光率 ,萘EC50 为 4 .32mg/L ,而菲及荧蒽浓度近其溶解度时所产生的最大抑光率分别为 <5 0 %和15 %左右 ;芘及蒽最大浓度时则对发光细菌无生物毒性显示。表明Microtox技术可有效检测低环化合物萘的生物毒性 ,但对高环化合物 (≥ 3环 )的检测因受其低水溶性的限制而灵敏度降低 ,利用二甲亚砜获取多环芳烃污染物提取液的生物毒性主要与低分子化合物萘及菲有关     

生物监测在水环境污染监测中的现状与展望

本文介绍了水质生物监测的定义、原理及其特点和主要方法:生物群落法、细菌学检验法、水生生物毒性试验、生产力测定法、微型生物监测、分子生态毒理学方法、硝化细菌测试法、幼虫变态实验、发光细菌毒性检测法、生物传感器、DNA生物传感器、聚合酶链反应技术,展望了生物监测的应用前景。     

石油污染土壤的生态风险评价和生物修复 Ⅱ.石油污染土壤的理化性质和微生物生态变化研究

采用常规土壤理化分析、微生物培养法以及碳素利用法(Biolog)和发光细菌生物毒性测定等新兴微生态研究方法,研究了石油污染引起的土壤理化性质和微生物功能多样性等微生态的变化。结果表明,石油污染使土壤有机质含量增加,pH降低,而对全磷、全钾、速效钾、全氮和水解氮无显著影响。平板计数显示石油污染对土壤中的细菌总量没有显著影响,但由于石油污染物的刺激作用导致污染土壤中总烃降解菌数以及芳烃降解菌数增加了几个数量级。Biolog的研究也表明,石油污染导致土壤微生物Gini指数、McIn-tosh指数和McIntosh均匀度等多样性指数增加,说明石油污染刺激了土壤中微生物的生长,使土壤中微生物多样性增加。而生物毒性试验表明,石油污染土壤对发光细菌具有毒性,其EC50为1 950μg ml-1。     

黄棕壤添加重金属的毒性评价及其临界浓度确定

在连续盆栽水稻、小麦的过程中研究了加入黄棕壤的Cu、Cd、Pb的毒性(发光细菌法)。结果表明,当以水提取黄棕壤中三元素,浓度低,不显毒性,这与水提取红壤的结果相反;当以0.1mol L^-1HCI提取黄棕壤中三元素,则浓度明显提高而显示毒性。在相关显著水平P=0.001的基础上建立了土壤金属浓度与剩余发光度(毒性指标)优化拟合方程。规定含金属土壤的临界剩余发光度为90%(EC₁₀)。据此,估算出黄棕壤中Pb、Cu、Cd的临界浓度(μg/g土)分别为:488-587,17.8-25.3,2.11-2.12。     

重金属汞、镉和铬对明亮发光杆菌的生物毒性

以明亮发光杆菌（Photobacterium phosphoreum）T3变种作为毒性测试物种,测定了重金属Hg2＋、Cd2＋和Cr6＋的单一毒性;采用二次二因子回归通用旋转组合实验设计,研究了Hg2＋＋Cd2＋、Hg2＋＋Cr6＋和Cd2＋＋Cr6＋3种二元重金属混合物的联合毒性作用和主因子作用,建立了3个相应的数学模型。结果表明,与单一重金属Hg2＋、Cd2＋与Cr6＋相比,它们的二元混合物对明亮发光杆菌生物毒性的效应和强度完全不同;单一重金属Hg2＋、Cd2＋与Cr6＋对明亮发光杆菌的毒性有显著的正效应,毒性从大至小依次为Hg2＋、Cd2＋、Cr6＋,对明亮发光杆菌的EC50分别为0.044、6.05mg·L-1和30.65mg·L-1;3种二元重金属混合物对发光细菌的联合毒性作用也不同,总体上,Hg2＋与Cd2＋、Cd2＋与Cr6＋为加和作用,而Hg2＋与Cr6＋以拮抗作用为主。     

夹竹桃（Nerium indicum）皂甙对鲫鱼（Carassius auratus）幼鱼的影响

为了评价夹竹桃皂甙对非靶标生物的潜在危害,采用半静态法研究了不同浓度（0、5.89、20.12mg·L-1和80.76mg·L-1）的夹竹桃皂甙对鲫鱼幼苗的死亡情况、特定生长率、糖原、蛋白质含量、SOD酶活性和微核率的影响。结果表明,当夹竹桃皂甙处理浓度≤20.12mg·L-1时,处理组的鲫鱼在试验期间无死亡;而在80.76mg·L-1皂甙的处理下,鲫鱼5d后全部死亡。当皂甙染毒浓度达20.12mg·L-1时,随处理时间的增加,特定生长率、糖原和蛋白质含量逐渐下降,而SOD活性先上升后下降;在清水中恢复饲养7d后,鲫鱼幼苗特定生长率和SOD活性受到的抑制作用逐渐减弱,糖原和蛋白含量恢复至与对照组相比无显著差异。此外,微核试验表明夹竹桃皂甙对鲫鱼幼苗的微核率无影响。研究结果表明,夹竹桃皂甙对鲫鱼的毒性属低等毒性且未发现遗传毒性,但高浓度的皂甙能影响鲫鱼幼鱼的正常生理代谢,导致生长受到抑制,严重时可致其死亡。     

长江三角洲地区城市污泥对蚯蚓的急性毒性效应

应用滤纸法和自然土壤法测定了长江三角洲地区城市污泥及其与青紫泥混合后对蚯蚓的急性致死效应及慢性毒性效应。结果表明:滤纸法测定的污泥对蚯蚓的毒性症状出现快且严重,不同污泥对蚯蚓的毒性大小差别较大,致死中浓度(LC50)相对应的污泥与水比值(Rsw-LC50)范围在0.0010～0.0242之间。在供试的城市污泥中,上海贮泥池污泥对蚯蚓的毒性最大,上海脱水污泥5对蚯蚓的毒性最小。自然土壤法测定的污泥与土壤作用后对蚯蚓的毒性结果为:所有处理蚯蚓死亡率均为0,各污泥处理对蚯蚓体重增长率的影响差别不大,个别污泥处理蚯蚓体重增长率比对照处理低,即对蚯蚓的体重有负增长影响。与滤纸法各处理相比,中毒症状较轻微,仅极个别中毒症状较明显。与污泥的水浸液相比,污泥与土壤作用后对蚯蚓的毒性大大降低。     

The use of Folsomia candida (Collembola,Isotomidae) in bioassays of waste

There is a high probability that urban compost, sewage sludge and ash will come in contact with natural terrestrial ecosystems. The present paper investigates the extent to which the Folsomia candida population development test (now a standardised ecotoxicological test, ISO 11267, for testing the impact of pure chemicals on soil fauna) can be applied to the detection of the toxicity of these wastes, the goal being to evaluate ecotoxicity of wastes before they are spread on land. We show that some potentially useful information on waste toxicity can be obtained with this test, but the results must be interpreting with caution, indeed, problems can arise from differences in pH, humidity and organic matter content of the waste relative to the characteristics of the dilution soil. On the basis of the results of these assays, we propose a classification of the toxicity of seven wastes.     

Contamination of soils and groundwater with new organic micropollutants: A review

The input of organic micro- and nanopollutants to the environment has grown in recent years. This vast class of substances is referred to as emerging micropollutants, and includes organic chemicals of industrial, agricultural, and municipal provenance. There are three main sources of emerging pollutants coming to the environment, i.e., (1) upon soil fertilization with sewage and sewage sludge; (2) soil irrigation with reclaimed wastewater and (3) due to filtration from municipal landfills of solid wastes. These pollutants contaminate soil, affect its inhabitants; they are also consumed by plants and penetrate to the groundwater. The pharmaceuticals most strongly affect the biota (microorganisms, earthworms, etc.). The response of microorganisms in the contaminated soil is controlled not only by the composition and the number of emerging pollutants but also by the geochemical environment.     

Ecotoxicological assessment of organic wastes using the soil collembolan Folsomia candida

The reproduction test with the collembolan Folsomia candida is used as a tool to evaluate the ecotoxicological potential of organic wastes currently applied to soil. Seven organic wastes (dewatered sewage sludges, thermally dried sewage sludges, composted sewage sludges, and a thermally dried pig slurry) were tested. These wastes had different origins, treatments, and pollutant burdens, and were selected as a representative sample of the wide variety of wastes currently generated. F. candida showed varied sensitivity depending on the waste, but also depending on the endpoint assessed. Reproduction was more sensitive than survival, although no correlations between reproduction and physico-chemical parameters and pollutant burden could be found. On the other hand, mortality was directly related to the lack of stability of wastes, probably reflecting the toxicity of end-products such as ammonium. Body length was not shown to be a sensitive endpoint for waste testing, as it was neither affected nor even stimulated by waste concentrations.Organic matter, pH, and electrical conductivity varied with waste concentration in soil-waste mixtures, although their effect on collembolan performance was expected to be low and part of the complex effect exerted by wastes when applied to real soils. Selection of the water content is the most problematic aspect in waste testing, as it may affect the performance of test organisms. In this study, a qualitative approach for water content selection in waste testing was considered to be the most suitable.Treatment of wastes affected composition and toxicity. Composting of sewage sludge increased its stability, compared to the initial sludge, but decreased its non-persistent organic pollutant burden and toxicity. On the other hand, thermally dried wastes from sludge and pig slurry displayed high toxicity, mainly attributable to their low stability. The results from the study indicate the inability of chemical methods to predict the effects of complex mixtures on living organisms with respect to ecotoxicity bioassays, but also the need for stabilization treatments of organic wastes prior to their reuse in soils.     

Phytotoxicity of some chloroanilines and chlorophenols, in relation to bioavailability in soil

Soil adsorption and the effect of four chlorophenols and three chloroanilines on the growth of lettuce (Lactuca sativa) were determined in two soil types differing in organic matter content and pH. Adsorption increased with increasing organic matter content of the soils. Phytotoxicity, based on dosed amounts, was significantly higher in the soil with the low level of organic matter. This difference could be reduced by recalculating the EC₅₀ values for the effect of the test substances on plant growth in mg kg-1 dry soil towards concentrations in mg L-1 pore water using data from soil adsorption experiments. For pentachlorophenol only this recalculation increased rather than decreased the difference between the two soils, however, when the EC50 values for pentachlorophenol were corrected for the difference in soil pH, almost the same values resulted for both soils. Calculated EC₅₀ values on the basis of pore water concentrations appeared to be in good agreement with values determined in nutrient solution tests. These results indicate that, for plants, the toxicity and therefore the bioavailability of organic chemicals in soil mainly depend on the concentration in the soil solution, and can be predicted on the basis of sorption data. Attempts to develop QSARs relating log EC₅₀ values in μmol L^?1 pore water with lipophilicity (expressed as the octanol/water partition coefficient: log K_ow,) of the test substances resulted in a statistically significant relationship. This relationship was further improved by correcting the chlorophenol data for dissociation effects.     

沙地整治下榆林土地利用及土壤有机质时空分异特征

毛乌素沙地是典型的生态脆弱区,近年来针对其在榆林境内的沙地整治利用取得显著成效,也对土壤环境产生了深刻影响。为了探究沙地不同整治利用方式对土壤有机质的影响,该研究选取榆林市显性沙地,利用多光谱遥感影像及相关光谱指数,结合沙地土地利用变化特征,通过XGBoost机器学习方法,反演1990—2020年土壤有机质含量;分析不同土地类型下土壤有机质含量变化,通过半变异函数揭示了其空间变异性,厘清人为因素和自然环境的影响程度。结果表明,30 a间榆林5 460 km2沙地中超过半数得到整治和利用,沙地-草地是最主要的地类转变方式,建设用地面积增长最迅速;沙区土壤有机质含量上升,但整体呈现先增加后降低的趋势,有机质均值由0.34%增长至0.79%,近10年降低至0.51%;榆林沙区土壤有机质具有较强的空间自相关性。起初,人为利用对其有积极作用,但随着沙地的利用强度增大,对土壤有机质产生负向作用,进而致使其含量下降,面临土地退化危机。建议加强退化林草的修复改良,放缓建设用地开发力度,研究以期为沙地整治提供理论和实践借鉴意义,保护榆林沙地土壤环境安全。     

Recycling municipal wastes in the future: from organic to inorganic forms?

Abstract. This paper highlights the principal problems related to the recycling of municipal wastes to arable land and outlines future solutions. History reveals that transport of sewage with water was introduced early (2500 bc ), but only some Asian societies, which did not utilize sewage flushing, redistributed toilet wastes to arable land effectively. Nutrient flow analyses in developed countries indicate a withdrawal of 20 kg N and 3 kg P ha⁻¹ yr⁻¹ from arable land because of non-return of organic human wastes. Limited reuse of municipal organic wastes in agriculture in several European countries is often seen as a question of waste quality. However, we believe that despite acceptable quality levels only minor progress in recycling has been achieved. Higher water contents in organic wastes than in harvested crops and, consequently, high costs for drying or transportation of wastes, often in combination with non-optimal plant nutrient composition, will remain the bottleneck which restricts the recycling of nutrients in wastes. One solution is to extract nutrients out of organic wastes and thereby derive concentrated compounds similar to those in inorganic fertilizers that can be redistributed and applied to soil. The challenge for modern sewage treatment systems is to shift perspective from removal to recovery of nutrients.     

Terrestrial Ecotoxicity of Eight Chemicals in a Systematic Approach (7 pp)

Background and Objective   Terrestrial ecotoxicity data are required for many research purposes. The data are derived either from the literature or elaborated by own investigations. As the terrestrial toxicity tests are usually time-consuming and labour intensive, the experiments are performed with a limited number of test organisms and soils. In the context of a project sponsored by CEFIC-LRI (European Chemical Industry Council – Long-Range Research Initiative), EC50-values were systematically elaborated for eight chemicals with a wide range of logKow-values (CdCl2, Trinitrotoluene, 3,4-dichloroaniline, 2,4-dichlorophenol, Tributyltinchloride, Pentachlorophenol, Benzo(a)pyrene, p,p-dichloro-2,2-diphenyl-1,1,1-trichloroethane). The substances were selected covering a broad range of physico-chemical and ecotoxicological properties. As toxicity endpoints, microbial activities, plant germination and growth as well as reproduction of earthworms and collembola were determined. As such systematic investigations are rarely performed and for some substances no data existed, the data pool is made available to the scientific community.Methods   All toxicity tests were conducted on three different soil types (sandy soil, silty soil, loamy soil), according to ISO and OECD guidelines Results, Discussion, Conclusion and Outlook   The different toxicities of the chemicals, the influence of soil properties on bioavailability as well as different sensitivities of test organisms and test parameters are reflected by the EC50-values. The results showed that the EC50-values calculated on the basis of nominal concentrations can significantly vary from EC50-values derived from analytical concentrations for some substances. To avoid false conclusions, this has to be considered especially when concentrations determined in the field are compared with toxicity data obtained from the literature or calculated on the basis of nominal concentrations. Moreover, the results indicate that terrestrial ecotoxicological tests should be accompanied by chemical analyses, to be sure to derive sound EC50-values. As the tests were performed according to international guidelines, the comprehensive data pool relevant for the terrestrial ecotoxicity of eight chemicals is considered to be of great value for further research and discussions dealing with the habitat function of soils.     

农药废水对秀丽隐杆线虫毒性效应及其主要有毒组分

应用battery生物测试法,检测研究农药废水对秀丽隐杆线虫的生命周期、繁殖速率、生殖能力、头摆和身体弯曲频率等影响的生物毒性,及其引发生物毒性的主要有机污染物。结果表明,在已经达到国家废水排放标准[GB 8978—1996]情况下,处理出水对受试动物仍然存在致毒效应;线虫的世代周期对进水的毒性最为敏感,产卵数量对出水的毒性最为敏感;进水毒性主要来自易受酸性调节影响的有机污染物,出水毒性主要来自易受碱性调节影响的有机污染物。结果表明,该项生物测试的毒性参数,可用于指示存在于低CODCr废水中的生物毒性;所用的毒性鉴别评价（TIE）方法,可用于鉴别废水中引发致毒效应的关键污染物。废水中悬浮颗粒污染物的生物毒性至关重要,尚未研究,有待继续。     

城市不同功能区绿地土壤理化性质及微生物生物量的分布特征

为提高城市绿地生态系统服务功能和促进城市可持续发展,本文研究了南京市不同功能区绿地表层土壤理化性质和微生物生物量的分布特征。结果显示:土壤p H整体呈碱性且容重偏大;公园绿地土壤全氮、有效磷和速效钾含量显著高于道路绿地;不同功能区绿地土壤有机质含量无显著差异,但公园绿地土壤微生物生物量碳含量和微生物熵显著高于居住区和道路绿地;公园绿地土壤结构和养分均优于道路绿地。土壤微生物生物量碳含量与有机质、全氮和速效钾含量呈极显著正相关,与有效磷含量呈显著正相关,与容重呈极显著负相关;土壤有机质与全氮和速效钾含量呈极显著正相关,与有效磷含量和pH无显著相关性,与容重呈显著负相关。因此,勤松土,合理施肥,增加枯枝落叶等凋落物覆盖,提高土壤养护管理水平对修复城市土壤生态和建设生态城市具有重要意义。     

Recycling of sewage sludge and household compost to arable land: fate and effects of organic contaminants, and impact on soil fertility

Effective use of organic wastes for agricultural production requires that risks and benefits be documented. Two types of sewage sludge, household compost and solid pig manure were studied under field and greenhouse conditions to describe their fertilizer value and effects on soil properties and soil biota, the fate of selected organic contaminants, and their potential for plant uptake. A 3-year field trial on two soil types showed no adverse effects of waste amendment on crop growth, and a significant fertilizer value of one sludge type. Accumulation of N and P_i was indicated, as well as some stimulation of biological activity and micro-arthropod populations, but these effects differed between soil types. There was no detectable accumulation of polycyclic aromatic hydrocarbons (PAH), di(2-ethylhexyl)phthalate (DEHP), nonylphenol and ethoxylates (NP+NPE) or linear alkylbenzene sulfonates (LAS) after three repeated waste applications, and no plant uptake was suggested by analysis of the third crop. A plot experiment with banded sludge was conducted to examine sludge turnover and toxicity in detail. Less than 5% of NP or LAS applied in organic wastes was recovered after 6 months, and less than 6% of DEHP applied was recovered after 12 months. Potential ammonium oxidation (PAO) at 0–1 cm distance from the banded sludge was stimulated despite toxic concentrations in the sludge, which suggested that contaminants were degraded inside sludge particles. Phospholipid fatty acid (PLFA) profiles suggested a gradual shift in the composition of the microbial community within sludge, partly due to a depletion of degradable substrates. A pot experiment with sludge-amended soil and soil spiked with contaminants showed no plant uptake of NP, DEHP or LAS. Degradation of LAS and NP added in sludge was delayed and the degradation of DEHP was faster than when the contaminants were added directly to the soil. In conclusion, adverse effects of organic waste application on soil or crop were not found in this study, and for some waste products positive effects were observed.