铁盐和铝盐混凝对印染废水生化出水中溶解性有机污染物的去除特性

以三氯化铁和硫酸铝为混凝剂,印染废水二级生化出水为研究对象,并利用XAD-8/XAD-4吸附树脂联用技术将印染废水生化出水中溶解性有机物分为疏水酸、非酸疏水物质、弱疏水物质及亲水物质4类有机物,通过小试实验探讨了2种混凝剂对生化出水中各类溶解性有机物的去除效果及特点。实验结果表明,对于该印染废水的生化出水,溶解性有机物的主要成分是疏水性物质,以DOC表征时占总DOC的75%,其中疏水酸约占41%,疏水性物质也是引起色度的主要物质,所占比例以ADMI7.6表征时为89%,其中以非酸疏水物质的贡献最大,达到52%,并且非酸疏水物质中不饱和双键或芳香环有机物的含量较高。在三氯化铁和硫酸铝各自最佳的混凝条件下,均能够有效去除由疏水性物质（疏水酸和非酸疏水物质）引起的色度,但三氯化铁对弱疏水性物质以及亲水物质的去除率高于硫酸铝,这使得三氯化铁对印染废水生化出水中的溶解性有机物的去除效果优于硫酸铝。并且三氯化铁和硫酸铝混凝工艺均能明显降低生化出水的毒性。     

采油用油田化学剂对鱼类的急性毒性实验研究

以白鲢鱼为实验生物,采用半静态实验方法,研究了几种油田化学剂的半致死浓度和安全浓度。研究表明:防膨剂、杀菌剂K、杀菌剂L、清蜡剂、四氟硼酸、酸化缓蚀剂、阻垢剂、阻垢缓蚀剂、缓蚀阻垢剂和破乳剂的96h半致死浓度LC50值分别为0.68、1.6、9.3、25、123、510、620、3240、4570、7410mg/L。根据化学物质对鱼类毒性物质分级标准,防膨剂属于剧毒物质;杀菌剂K、杀菌剂L和清蜡剂属于高毒物质;四氟硼酸、酸化缓蚀剂和阻垢剂属于中毒物质;阻垢缓蚀剂、缓蚀阻垢剂和破乳剂属于低毒物质。这几种油田化学剂的安全浓度为0.068～741mg/L。此研究可为评价油田化学剂对水生生物的影响,制定废水排放浓度标准提供依据。     

Predicting molybdenum toxicity to higher plants: Estimation of toxicity threshold values

Four plant species (oilseed rape, Brassica napus L.; red clover, Trifolium pratense L.; ryegrass, Lolium perenne L.; and tomato, Lycopersicon esculentum L.) were tested on ten soils varying widely in soil properties to assess molybdenum (Mo) toxicity. A larger range (66-fold-609-fold) of added Mo concentrations resulting in 50% inhibition of yield (ED₅₀) was found among soils than among plant species (2-fold-38-fold), which illustrated that the soils differed widely in the expression of Mo toxicity. Toxicity thresholds based on soil solution Mo narrowed the variation among soils compared to thresholds based on added Mo concentrations. We conclude that plant bioavailability of Mo in soil depends on Mo solubility, but this alone did not decrease the variability in observed toxicity enough to be used in risk assessment and that other soil properties influencing Mo toxicity to plants need to be considered.     

中国环境效率评价及其影响因素实证研究

环境效率是实际污染排放和潜在污染排放的一种度量。本文运用包含污染排放的环境DEA模型,测算了1998-2007年中国省际环境效率,检验了其收敛情况。结果显示,全国环境效率总体水平较低,省际、区域间差距较大,表明现阶段实行地区间减排合作、推动环保技术在区域间扩散的现实必要性;分别从20032、005年开始,省际、区域环境效率差距逐渐缩小,存在一定的收敛趋势;同时,本文采用Tobit模型分析了影响环境效率因素,研究发现人均GDP对提高环境效率具有积极影响,而工业比重上升、财政分权度的提高以及贸易自由化对环境效率具有显著的负面影响。最后,基于实证研究的结果,就减少地区污染排放、提高我国环境效率给出了相关政策建议。     

基于元素毒性赋值的模糊数学环境质量评价

利用模糊数学方法,根据元素毒性的大小进行权重赋值,对成都经济区近地表大气尘进行地球化学环境质量评价。结果显示：不同城市中,成都、乐山、眉山的大气环境质量较好,处于一级清洁级别;眉山、雅安的大气环境质量处于二级安全级别;德阳的大气环境质量已经处于三级警戒级。不同地区中,绵阳和眉山的大气环境质量较好,处于一级清洁级别;德阳和雅安处于二级安全级别,成都和乐山处于三级警戒级.     

上海霾气候数据序列重建及其时空特征

利用上海11个气象站点1960～2008年日均相对湿度、能见度以及天气现象资料,重建了上海近50a霾气候数据序列,并从时间和空间两个方面分析了上海霾日数的气候特征和变化规律。结果表明,上海霾气候数据序列重建值与报表记录值之间变化形态存在着较好的一致性,重建值较记录值偏高。1960～2008年,上海霾日数以9.7d/10a的线性趋势显著增加,2002年以后霾日数总体上呈减少趋势。上海多年平均霾日数以冬季最多而夏季最少。近50a,上海霾日数呈现出西南部最多-市区较多-东北和东南部最少的空间分布,霾日数的空间变化趋势则表现为西南部增加较多而东部增加较少。1981～2008年,上海霾日数在西部和南部都增加,东部则减少。     

Simulation of a Hazardous and Noxious Substances (HNS) spill in the marine environment: Lethal and sublethal effects of acrylonitrile to the European seabass

Despite the extensive maritime transportation of Hazardous and Noxious Substances (HNS), there is a current lack of knowledge on the effects posed by HNS spills on the marine biota. Among the HNS identified as priority, acrylonitrile was selected to conduct ecotoxicological assays. We assessed the acute and subletal effects of acrylonitrile in seabass, followed by a recovery phase to simulate the conditions of a spill incident. The work aimed at testing a broad range of biological responses induced by acrylonitrile. Sublethal exposure to the highest two doses increased the fish mortality rate (8.3% and 25% mortality in 0.75 and 2 mg L⁻¹ acrylonitrile concentrations), whereas no mortality were observed in control and 0.15 mg L⁻¹ treatments. Additionally, important alterations at sub-individual level were observed. Acrylonitrile significantly induced the activities of Catalase– CAT and Glutathione S-Transferase – GST; and the levels of DNA damage were significantly increased. Conversely, Superoxide Dismutase– SOD – activity was found to be significantly inhibited and no effects were found on Lipid Peroxidation– LPO and ethoxyresorufin O-deethylase – EROD – activity. Following a 7 d recovery period, the levels of CAT, GST and EROD fell to levels at or below those in the control. In the 2 mg L⁻¹ group, SOD remained at the levels found during exposure phase. This study has gathered essential information on the acute and subletal toxicity of acrylonitrile to seabass. It also demonstrated that 7 d recovery allowed a return of most endpoints to background levels. These data will be useful to assist relevant bodies in preparedness and response to HNS spills.     

Effects of long-term chlorpyrifos exposure on mortality and reproductive tissues of Banded Gourami (Trichogaster fasciata)

Abstract

This study assessed the long-term toxicity of chlorpyrifos on survival and reproduction of Banded Gourami by using mortality, gonado-somatic index (GSI) and histopathological observations as endpoints. Adult fish were exposed to five different concentrations of chlorpyrifos (0, 15, 50, 150, 500?µg/L) in 15 PVC tanks for 15, 30, 45, 60 and 75?days. Results showed that all male and female fish died after 15?days of 500?µg/L chlorpyrifos exposure. No consistent significant effect was observed for both male and female GSI. Furthermore, results showed dose- and time-dependent histopathological alterations for both ovary and testes. The 60-d No Observed Effect Concentration (NOEC) for most histopathological alterations of Banded Gourami ovary and testes was 50?μg/L, while 60-d NOEC for mortality of both male and female fish was < 15?μg/L. The results show that the long-term exposure to chlorpyrifos not only affect the reproductive tissues of Banded Gourami at exposure concentrations but also cause their mortality. Future studies should evaluate effects at lower concentrations.     

Comparative acute toxicity of two phytosanitary molecules,lambda-cyhalothrin and acetamiprid,on Nile Tilapia (Oreochromis Niloticus) juveniles

Abstract

This study aimed to compare the toxicity for fish of two active ingredients (lambda-cyhalothrin-20?g L^?1, a pyrethroid, and acetamiprid-15?g L^?1, a neonicotinoid) which are components of a commercial insecticide (Acer 35 EC) used in cotton crop in many West African countries. The juveniles of Oreochromis niloticus (4.01?±?0.34?g, mean body weight) were exposed for 96?h to increasing concentrations of active ingredients (lambda-cyhalothrin and acetamiprid) or a mixture similar to Acer 35 EC (composed by 20?g of chemical compound lambda-cyhalothrin and 15?g of acetamiprid dissolved in 1?L of acetone). The experiments were carried out under controlled conditions in aquaria according to OECD Guidelines. During the experiments, the behavioral responses (loss of balance, color change, hyperactivity, etc.) that usually precede death were observed in exposed fish. Mortalities were recorded in each aquarium and the LC₅₀-96h of each chemical was determined. The LC₅₀-96h obtained were respectively 0.1268, 0.0029, 182.9 and 0.5685?ppm for Acer 35 EC, lambda-cyhalothrin, acetamiprid and mixture. All insecticides used in this study had profound impact on Nile tilapia behavior which may confirm the neurotoxicity of each single active compound as well as of their mixture.     

发光细菌法在水质综合毒性在线检测中的应用

以海洋发光细菌费氏弧菌（Vibriofischeri）作为检测生物,采用冻干菌粉快速复苏技术,研究费氏弧菌在水质检测中的最佳测试温度和有效性测试条件,并对硫酸锌等多种毒物和几种实际水样进行发光抑制作用分析。研究表明,费氏弧菌冻干粉复苏菌液保存在2～5℃条件下能有效测试7d,最佳测试温度为15℃,最佳测试时间为15min。氯化汞、硫酸锌、硫酸镉等重金属和苯胺、多菌灵、甲醛等有机毒物对费氏弧菌均具有较强的光抑制作用,也即费氏弧菌对以上毒物较为敏感,并能够连续7d保持对同一浓度硫酸锌的敏感性较为一致。对几种实际水样的测试和分析表明,以费氏弧菌为指示生物的发光细菌法能够应用于水质环境安全的综合毒性在线监测预警中。