A model compound study: the ecotoxicological evaluation of five organic contaminants employing a battery of marine bioassays

This paper describes the ecotoxicological evaluation of five organic contaminants frequently detected in marine sediments (tributyltin, triphenyltin, benzo[a]pyrene, fluoranthene, and PCB 153) using three marine species (Vibrio fischeri, Tetraselmis suecica, and Tisbe battagliai). The sensitivity of each species varied for all compounds. The triorganotins were consistently the most toxic to all species. The applicability of each test system to assess the acute toxicity of environmental contaminants and their use in Toxicity Identification Evaluation (TIE) is discussed. Suitability of the Microtox and T. battagliai tests for employment in TIE studies were further assessed through spiking experiments with tributyltin. Results demonstrated that the most effective treatment to remove organotin toxicity from the sample was the C18 resin. The results of this study have important implications for risk assessment in estuarine and coastal waters in Ireland, where, at present the monitoring of sediment and water quality is predominantly reliant on chemical analysis alone.     

利用发光菌和大型蚤对北方某城市再生水急性毒性的调查

利用发光菌和大型蚤作为受试生物测定了北方某城市5个再生水原水(城市污水厂二级出水)和2个再生水处理系统的各工艺出水的急性毒性.结果表明,各再生水原水对大型蚤和发光菌具有不同程度的毒性效应,其中工业废水占较大比例的K和B厂再生水原水的大型蚤48 h总抑制率分别高达90%和100%,发光菌发光抑制率分别达到74.2%和46...     

Assessment of a process to degrade metal working fluids using Pseudomonas stutzeri CECT 930 and indigenous microbial consortia

The development of a novel biological process to treat metal working fluids (MWFs)-containing effluents at bioreactor scale was pursued in this work. The bacteria Pseudomonas stutzeri CECT 930 was investigated for the first time as an alternative agent for MWF degradation. An adequate medium design and mixing and aeration system, as well as an appropriate microorganism proved to be crucial for reaching high levels of degradation by P. stutzeri and by an indigenous consortium (about 70% and 50% of reduction in total petroleum hydrocarbon content in less than 2 wk, respectively). Additionally, as there is no information in literature trying to kinetically characterize an MWF-polluted effluent degradation process, all the experimental data were fitted to logistic and Luedeking and Piret models, that allowed to elucidate the growth-associated character of the biodegradation process.     

地表水中隐孢子虫和贾第鞭毛虫微球的混凝去除

以向地表水中投加的隐孢子虫微球和贾第鞭毛虫微球为对象,研究通过对给水混凝工艺对其的去除效果进行比较,着重考察了不同混凝剂种类、投加量及水样pH值对去除效果的影响.结果表明,混凝工艺可较为有效地去除地表水中的两虫微球,去除率最高可达4 lg.相比常规的金属盐类混凝剂,高分子的PAC、PAFC混凝剂对两虫微球的混凝去除率更...     

不同水温下鲴鱼对铜绿微囊藻的控制作用及对水质的影响

在室内受控模拟条件下开展实验,研究了在19、23、27、31、35℃5个水温梯度下鲴鱼对铜绿微囊藻和水质的影响。研究结果表明,在不同水温下,鲴鱼对铜绿微囊藻具有较强的控制作用,实验结束时铜绿微囊藻密度减少至初始密度的18%~30%,摄食率和消化率分别为6.83×104~8.32×104cells/(g·d)、93%~98%;叶绿素a的去除率为68%~88%;实验组TP、TN去除率分别为22%~25%、20%~38%,对照组的分别为80%~94%、28%~40%。对照组NH+4-N浓度变化很小(0.071~0.073 mg/L),而实验组氨氮浓度显著增大(2.222~3.645 mg/L),分别为初始值的31、34、42、51和46倍。     

Toxic effects of chemical pesticides (trichlorfon and dimehypo) on Dunaliella salina

Dunaliella salina, a unicellular green alga of environmental tolerance, was employed as test organism to investigate the toxicity effects of trichlorfon and dimehypo widely used in agriculture and veterinary as pesticides. The influences of trichlorfon and dimehypo on cell growth, β-carotene level, cell morphology changes, and activities of superoxide dismutase (Sod) and catalase (Cat) were investigated. At the concentrations less than 0.050 g L⁻¹ trichlorfon or 0.0005 g L⁻¹ dimehypo, cell responses were similar to control. When treated with 0.075-0.100 g L⁻¹ trichlorfon or 0.001-0.004 g L⁻¹ dimehypo, cell growth and β-carotene levels declined at first and then revived. When concentrations were higher than 0.125 g L⁻¹ trichlorfon or 0.005 g L⁻¹ dimehypo, both cell growth and β-carotene levels decreased until they were undetectable. The 10-d IC50 of trichlorfon and dimehypo on D. salina were 0.179 g L⁻¹ and 0.032 g L⁻¹. Both pollutants could stimulate the increase of Cat activity at a low concentration. Tolerance of D. salina to trichlorfon was obviously higher than that of dimehypo.     

Correlation and toxicological inference of trace elements in tissues from stranded and free-ranging bottlenose dolphins (Tursiops truncatus)

The significance of metal concentrations in marine mammals is not well understood and relating concentrations between stranded and free-ranging populations has been difficult. In order to predict liver concentrations in free-ranging dolphins, we examined concentrations of trace elements (Al, As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Ni, Pb, Sb, Se, Sn, total Hg (THg), V, Zn) in skin and liver of stranded bottlenose dolphins (Tursiops truncatus) from the South Carolina (SC) coast and the Indian River Lagoon, Florida (FL) during 2000-2008. Significantly higher concentrations of Zn, Fe, Se, Al, Cu and THg were found in skin while liver exhibited significantly higher Cu, Fe, Mn and THg concentrations for both study sites. Mean skin concentrations of Cu and Mn were significantly higher in SC dolphins while higher concentrations of THg and V were found in FL dolphins. In addition, liver tissues in SC dolphins exhibited significantly higher As concentrations while higher Fe, Pb, Se, THg, and V levels were found in FL dolphins. Two elements (Cu and THg) showed significant age-related correlations with skin concentration while five elements (Cu, Se, THg, Zn and V) showed age-related correlations with liver concentrations. Geographic location influenced age-related accumulation of several trace elements and age-related accumulation of THg in hepatic tissue was observed for both sites to have the highest correlations (r² = 0.90SC; r² = 0.69FL). Mean THg concentration in liver was about 10 times higher in FL dolphins (330 μg g⁻¹ dw) than those samples from SC dolphins (34.3 μg g⁻¹ dw). The mean molar ratio of Hg to Se was 0.93 ± 0.32 and 1.08 ± 0.38 for SC and FL dolphins, respectively. However, the Hg:Se ratio varied with age as much lower ratios (0.2-0.4) were found in younger animals. Of the 18 measured elements, only THg was significantly correlated in skin and liver of stranded dolphins and skin of free-ranging dolphins from both sites suggesting that skin may be useful in predicting Hg concentrations in liver tissue of free-ranging dolphins. Results indicate that 33% of the stranded and 15% of the free-ranging dolphins from FL exceed the minimum 100 μg g⁻¹ wet weight (ww) (∼400 dw) Hg threshold for hepatic damage while none from SC reached this level. Hepatic concentrations of As in SC dolphins and V in FL dolphins were also highly correlated with skin concentrations which may have some regional specificity predictive value. The present study provides the first application of trace element concentrations derived from stranded bottlenose dolphins to predict liver concentrations in free-ranging populations.     

桉树人工林地土壤养分和重金属现状分析与评价

为了评价大面积人工种植桉树对当地土壤养分变化和重金属富集效应的影响,本研究以普洱市3.75万hm²桉树人工林为研究对象,通过定位观测并将其与当地次生林、撂荒地进行比较,分析土壤养分变化情况、重金属污染等级以及两者之间的相关性。结果表明,桉树林表层土壤养分的含量均高于背景值,其中有效磷、水解性氮、全磷、全钾、有机质和速效钾极显著高于撂荒地（P<0.01）,全氮略高但差异不显著;与次生林相比,桉树林土壤养分全氮和水解性氮显著低（P<0.05）,全钾和全磷的含量显著高（P<0.05）,有效磷的含量极显著高（P<0.01）,有机质和速效钾略高但差异不显著。桉树林表层土壤样品重金属综合污染指数为1.08,低于撂荒地的1.14而高于次生林的0.67,说明桉树林土壤已处于轻微度污染等级,有可能会引起农作物污染,其中铅、锌、铜、镍、砷和铬等6种重金属含量处于安全水平,而镉的单因子污染指数值介于1~2之间,表明桉树林土壤属于轻度镉污染,但相关性分析结果表明,桉树林表层土壤养分的含量与重金属的含量无显著相关。     

菖蒲和空心菜在处理微污染河水潜流人工湿地中的应用

为了探讨修复微污染河水的潜流湿地中植物对污染物去除效果的影响及其生长变化,在野外条件下构建2座分别栽种菖蒲和空心菜的水平潜流人工湿地,并以未栽种植物的湿地作空白。分析了湿地中污染物的去除效果,考察了湿地中植物的生物量、根系活力和氮磷含量的变化。植物湿地中污染物净化效果优于空白湿地,菖蒲和空心菜湿地对氨氮(NH+4-N)、总氮(TN)、总磷(TP)和高锰酸盐指数(CODMn)的平均去除率分别为61.1%和57.5%,31.5%和39.7%,24.7%和25.5%,20.4%和20.7%。实验结果表明,湿地中菖蒲的根系鲜重是空心菜的4.2倍,但其根系活力低于空心菜。2种植物均可在湿地中正常生长,但受湿地中营养盐浓度的限制性影响,移栽后的植物组织氮磷含量与移栽前相比下降了11.8%~20.3%。植物在净化微污染河水的潜流人工湿地中对N、P的去除起重要作用。     

Escherichia coli and total coliforms in water and sediments at lake marinas

Escherichia coli, a fecal coliform, and total coliforms were monitored between September 1999 and October 2001 in five marinas at Lake Texoma, located on the Oklahoma and Texas border. The general trend was that densities of E. coli were lower in the summer season due to the lower loading of fecal material into Lake Texoma and the ecological conditions of the lake, such as more vigorous grazing by protozoa and less viability of E. coli at an elevated temperature. The densities of total coliforms greatly increased in the summer. E. coli levels increased with depth, and the bottom water samples had higher densities of E. coli mainly due to their association with particles. There was a direct relationship between amount of gasoline sold, which was related to recreational boating activity, and the resuspension of E. coli. This indicated that recreational boating activity in lake marinas may have resuspended bottom sediments with bound E. coli, and the presence of E. coli in marinas was not an indication of recent fecal contamination. E. coli were detected in the largest densities at the boat dock points, followed by the gasoline filling station, and marina entrance. In addition, enumeration of bacteria in bottom sediment showed that the densities of E. coli and total coliforms in sediment were much higher compared to those in lake water.     

Combination of in vitro bioassays for the determination of cytotoxic and genotoxic potential of wastewater, surface water and drinking water samples

In this study we evaluated genotoxicity and cytotoxicity of native samples of wastewaters (15 samples), surface waters (28 samples) and potable waters (8 samples) with the SOS/umuC assay with Salmonella typhimurium TA1535/pSK1002 and MTT assay with human hepatoma HepG2 cells. The genotoxicity of selected samples was confirmed with the comet assay with HepG2 cells. In the SOS/umuC assay 13 out of the 51 samples were genotoxic: two effluent samples from chemical industry; one sample of wastewater treatment plant effluent; two hospital wastewater samples; three river water samples and four lake water samples. Six samples were cytotoxic for HepG2 cells: both effluent samples of chemical industry, two wastewater treatment plant effluent samples, and two river water samples, however, only the chemical industry effluent samples were genotoxic and cytotoxic, indicating that different contaminants are responsible for genotoxic and toxic effects. Comparing genotoxicity of river and lake water samples with the chemical analytical data of the presence of the residues of pharmaceutical and personal care products (non-steroidal anti-inflammatory drugs, UV filters and disinfectants) in these samples, indicated that the presence of UV filters might be linked to the genotoxicity of these samples. The results showed that the application of the bacterial SOS/umuC assay and mammalian cell assays (MTT and comet assay) with HepG2 cells was suitably sensitive combination of assays to monitor genotoxicity and cytotoxicity of native samples of wastewaters and surface waters. With this study we also confirmed that the toxicity/genotoxicity bioassays should be an integral tool in the evaluation of toxicity of complex wastewaters before the release into environment, as well as for the monitoring of surface water quality, providing data useful in risk assessment.     

大型蚤标志酶用于城市二级出水毒性的评价

大型蚤是一种国际公认的标准实验生物,广泛应用于污水、地表水等水质毒性检测。毒性水平较低的城市二级出水,对大型蚤往往无急性毒性效应,而具有慢性毒性效应,但慢性毒性检测周期过长,因此探索一种更灵敏的指标,实现快速检测,对于控制二级出水的水质风险具有重要意义。本研究考察了大型蚤在短期暴露于城市二级出水条件下,其体内乙酰胆碱酯酶、超氧化物歧化酶、过氧化氢酶、ATP酶、羧酸酯酶和碱性磷酸酯酶的酶活变化特征,从中筛选出对二级出水毒性响应灵敏的标志酶指标。实验结果表明,碱性磷酸酯酶、过氧化氢酶对二级出水毒性响应相对较灵敏,具有成为标志酶的潜力,研究结果为城市二级出水生物毒性评价方法优化提供新的思路。     

Assessment of manure-application effects upon the runoff water quality by algal assays and chemical analyses

The effects of manure-application mode, rate to soil, and rainfall characteristics on the quality of agricultural runoff water have been assessed by means of the algal-growth-potential test (AGPT) and chemical analyses. This study used two modes of manure application (i.e. surface mode and incorporation mode), three manure-application rates (0, 150, 300 kg N ha(-1)), and two rainfall intensities and times (i.e. 11 mm h(-1) for 142 min and 22 mm h(-1) for 71 min). The effects of the dilution of runoff water on algal growth were also examined. The algal yields obtained with runoff from soil with the incorporated manure mode are similar to those from soil without manure application and are lower than those with the surface mode of manure application. A higher manure-application rate increases the load of nutrients in the runoff and subsequently the algal yield. The dilution of runoff water can stimulate or limit the algal growth, depending on the concentration of toxicants, N (nitrogen) and P (phosphorus) from runoff and in the aquatic diluting medium. A lower rainfall intensity plus a longer rainfall time increases algal productivity. This study showed that N is the limiting factor to algal growth at low dilution but that, at high dilution or with the incorporation mode of manure application, P becomes the limiting factor to algal growth.     

固定化菌藻微球的制备、表征及其对富营养化湖水的修复

以聚乙烯醇(PVA)和海藻酸钠(SA)为主要包埋材料,以活性炭、SiO2和CaCO3作添加剂,采用普通小球藻(Chlorella vulgaris)和活性污泥制备固定化菌藻微球。采用正交实验对微球的制备条件进行了优化,并对最优化条件下制得的微球进行了表征,还考察了固定化菌藻微球对某富营养化湖水的修复效果。结果表明,固定化菌藻微球的最优化制备条件为:PVA用量10%(m/v),微生物包埋量15 mL,海藻酸钠用量0.6%(m/v),氯化钙浓度2.0%(m/v)。制得的微球具有较大的比表面积,内部呈网状结构,孔径分布均匀,中孔居多,适合小球藻和微生物生长。采用固定化菌藻微球可有效修复上述湖泊的实际富营养化湖水,微球可重复使用3~4个循环,在前4个循环中,每个循环历时96 h,TN平均去除率达80%以上;TP平均去除率达90%以上;COD平均去除率达85%以上,表明固定化菌藻微球在富营养化湖水的修复方面具有潜在的应用价值。     

耐寒人工湿地植物石龙芮和酸模联用研究

为了提高人工湿地在寒冷季节的运行效率,对2种非夏季植物作为湿地植物处理生活污水的可行性进行了研究。结果表明,在本实验条件下2种植物对N、P元素都具有很好的去除效果,对COD的去除也达到45%～50%。通过单一植物系统和复合植物系统的处理效果比较,发现石龙芮酸模复合植物系统对污水中的P元素和COD的去除率更高。研究表明,石龙芮和酸模作为人工湿地植物具有可行性,与常规植物互补使用能在一定程度上延长人工湿地的运行时间。     

The arbuscular mycorrhizal fungus Glomus mosseae can enhance arsenic tolerance in Medicago truncatula by increasing plant phosphorus status and restricting arsenate uptake

A pot experiment examined the biomass and As uptake of Medicago truncatula colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae in low-P soil experimentally contaminated with different levels of arsenate. The biomass of G. mosseae external mycelium was unaffected by the highest addition level of As studied (200 mg kg⁻¹) but shoot and root biomass declined in both mycorrhizal and non-mycorrhizal plants, indicating that the AM fungus was more tolerant than M. truncatula to arsenate. Mycorrhizal inoculation increased shoot and root dry weights by enhancing host plant P nutrition and lowering shoot and root As concentrations compared with uninoculated plants. The AM fungus may have been highly tolerant to As and conferred enhanced tolerance to arsenate on the host plant by enhancing P nutrition and restricting root As uptake.     

Phytoremediation potential of the novel atrazine tolerant Lolium multiflorum and studies on the mechanisms involved

Atrazine impact on human health and the environment have been extensively studied. Phytoremediation emerged as a low cost, environmental friendly biotechnological solution for atrazine pollution in soil and water. In vitro atrazine tolerance assays were performed and Lolium multiflorum was found as a novel tolerant species, able to germinate and grow in the presence of 1 mg kg⁻¹ of the herbicide. L. multiflorum presented 20% higher atrazine removal capacity than the natural attenuation, with high initial degradation rate in microcosms. The mechanisms involved in atrazine tolerance such as mutation in psbA gene, enzymatic detoxification via P₄₅₀ or chemical hydrolysis through benzoxazinones were evaluated. It was demonstrated that atrazine tolerance is conferred by enhanced enzymatic detoxification via P₄₅₀. Due to its atrazine degradation capacity in soil and its agronomical properties, L. multiflorum is a candidate for designing phytoremediation strategies for atrazine contaminated agricultural soils, especially those involving run-off avoiding.     

Cd、Ni单一及复合污染对土壤酶活性的影响

采用外源添加重金属和露天盆栽实验研究了Cd、Ni对含羞草、三叶草根际土壤脲酶、过氧化氢酶和蔗糖酶活性的影响。结果表明,Cd、Ni单一污染条件下,低浓度的Cd、Ni对含羞草组、三叶草组的脲酶、过氧化氢酶有激活作用,高浓度的Cd、Ni对土壤脲酶、过氧化氢酶有一定的抑制作用;对蔗糖酶有较强的抑制作用。在Cd、Ni复合污染条件下,对含羞草组、三叶草组的脲酶、过氧化氢酶和蔗糖酶产生抑制作用;Cd、Ni单一及复合污染对土壤酶活性的抑制大小顺序为:脲酶>蔗糖酶>过氧化氢酶,其中土壤脲酶可以作为Cd、Ni污染的预警指标。含羞草能显著提高土壤脲酶、过氧化氢酶和蔗糖酶的活性,修复能力大于三叶草,在Cd、Ni污染修复方面有很好的应用前景。     

Historical alteration in the nitrogen concentration and N natural abundance of mosses in Germany: Indication for regionally varying changes in atmospheric nitrogen deposition within the last 140 years

Historical alterations of nitrogen deposition in the western part of Germany were investigated by comparing nitrogen concentrations and ¹⁵N natural abundance of historical and recent samples of the two pleurocarpous mosses Pleurozium schreberi and Scleropodium purum. Pooling of the data revealed only slight tissue N increases over the past 140 years which were significant nevertheless. At closer examination on the single site level historical increases of N concentrations were found particularly for some sites in regions where agricultural activities were considerably intensified during the second half of the 20th century. The comparison of δ¹⁵N values showed a strong depletion of ¹⁵N natural abundance in areas currently heavily influenced by livestock management. This indicates an increased impact of NH_y compounds. However, the almost unchanged δ¹⁵N values in some low mountain range areas with only moderate intensification of agriculture point to a more or less constant ratio of NH_y/NO_x input over time. Significant correlations of both tissue N concentrations and ¹⁵N natural abundance between the two species justify the assumption that they use the same nitrogen source, probably atmospheric deposition.     

Acute toxicity and ecotoxicological risk assessment of rice pesticides to Lithobates catesbeianus tadpoles

The objective of this study was to determine the acute toxicity of some pesticides used in irrigated rice farming to Lithobates catesbeianus tadpoles. The LC_50-96h for commercial formulations containing bentazon, penoxsulam, vegetable oil, permethrin and carbofuran, separately and their mixtures, were determined at the proportions commonly used in the field. The limits of risk concentrations of these products for the studied species were also established. The LC_50-96h for tadpoles was 4,530 mg L^?1 for bentazon; 7.52 mg L^?1 for penoxsulam + 145.66 mg L^?1 of vegetable oil; 81.57 mg L^?1 for vegetable oil; 0.10 mg L^?1 for permethrin; 29.90 mg L^?1 for carbofuran (active ingredients), and 38.79 times the dose used in the field for the mixture of these products. The environmental risk was determined only for permethrin, and care should be taken when using the vegetable oil.