污染土壤中重金属生物有效性的植物指示法研究

污染土壤中重金属生物活性的判断是污染土壤修复的关键所在。植物指示法是近年来发展起来的判断污染土壤中重金属生物可利用性的一种经济简便且可靠的方法。综述了近年来国内外科研工作者在重金属污染程度的植物指示方面所做的工作，重点阐述了用指示植物监测环境污染以及指示植物的选择问题。     

Removal of Alachlor from Water by Catalyzed Ozonation in the Presence of Fe2+, Mn2+, and Humic Substances

Abstract

The effects of Fe(II), Mn(II) and humic substances on the catalyzed ozonation of alachlor, an endocrine disruptor were investigated. Results revealed that small amounts of Fe(II), Mn(II), and humic substances could enhance the ozonation of alachlor, but larger amounts of them would retard the oxidation. These results were successfully identified by an electron paramagnetic resonance (EPR) spectroscopy/spin-trapping method that could quantify hydroxyl radicals. The production of hydroxyl radicals was obviously increased with the increasing of Fe(II) concentration, which contributed to enhance ozonation at low concentrations. But the excess Fe(II) consumed some of the radicals when it was added at a higher concentration (1.5 mg/L). However, no obvious radicals were observed when a different amount of Mn(II) was used, and the catalytic ozonation of alachlor by Mn(II) mainly followed the mechanism of “active sites created on the surface of MnO₂.” The radical pathway was followed when alachlor was ozonated with different concentrations of humic substances because of its radical initiating, promoting, and inhibiting effects.     

雷州半岛土壤重金属分布特征及其污染评价

在雷州半岛采集了106个土壤表层样品,分析了其中8种重金属元素(Cu、Pb、Zn、Cr、Ni、Cd、Hg和As)的全量.结果表明,雷州半岛土壤重金属污染由高到低排序为Ni＞Cr＞Hg＞Cu＞Zn＞Cd＞As＞Pb,Zn、Cd、As和Pb质量浓度均没有超标,Hg和Cu质量浓度超标率亦不高,但Ni和Cr平均质量浓度达49.81、87.13 mg/kg,高于国内外其他对照区域,超标率分别为25.47%和24.53%;重金属元素在雷州半岛各土壤利用类型中分布规律不明显,按4种主要土壤利用类型受重金属污染程度大小排序为甘蔗地＞果园土＞水田＞菜地;雷州半岛土壤综合污染指数总平均为0.970,土壤总体上尚清洁,重金属污染处于警戒水平;雷州半岛各区域中,徐闻、雷州两地土壤重金属质量浓度明显高于其他地区,其主要原因是徐闻、雷州两地成土母质主要为玄武岩,造成土壤Cr、Ni及其他重金属背景值较高.     

Distribution of pesticides and heavy metals in trophic chain

Determination of triazines herbicides (atrazine and simazine) by high performance liquid chromatography (HPLC) in samples of trophic chain were worked out. Determination limits of 0.5 μg g⁻¹ for atrazine, 0.8 μg g⁻¹ for simazine with pesticides recovery of 70–77% in trophic chain samples were obtained. The content of simazine in soils was in range 1.72–57.89 μg g⁻¹, in grass 5–88 μg g⁻¹, in milk 2.32–15.29 μg g⁻¹, in cereals 10.98–387 μg g⁻¹, in eggs 30.14–59.48 μg g⁻¹, for fruits: 2.45–6.19 μg g⁻¹. The content of atrazine in soils was in range 0.69–19.59 μg g⁻¹, in grass 7.85–23.85 μg g⁻¹, in cereals 1.88–43.08 μg g⁻¹. Cadmium, lead and zinc were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) in the same samples as atrazine and simazine. Determination limits for cadmium 5 × 10⁻³ μg g⁻¹, for lead 1 × 10⁻² μg g⁻¹, and for zinc 0.2 × 10⁻³ μg g⁻¹, were obtained. The content of cadmium in soil was in range 0.13–5.89 μg g⁻¹, in grass 114–627.72 × 10⁻³ μg g⁻¹, in milk 8.88–61.88 × 10⁻³ μg g⁻¹, in cereals 0.20–0.31 μg g⁻¹, in eggs 0.11–0.15 μg g⁻¹, in fruits 0.23–0.59 μg g⁻¹. The content of lead in soils was in range 0.57–151.50 μg g⁻¹, in grass 0.16–136.57 μg g⁻¹, in milk 1.16–3.74 μg g⁻¹, in cereals 1.05–5.47 μg g⁻¹, in eggs 5.79–55.87 μg g⁻¹, in fruits 21.00–87.36 μg g⁻¹. Zinc content in soil was in range 9.15–424.5 μg g⁻¹, in grass 35.20–55.87 μg g⁻¹, in milk 20.00–34.38 μg g⁻¹, in cereals 14.94–28.78 μg g⁻¹, in eggs 15.67–32.01 μg g⁻¹, in fruits 14.94–18.88 μg g⁻¹.

Described below extraction and mineralization methods for particular trophic chains allowed to determine of atrazine, simazine, cadmium, lead and zinc with good repeatability and precision. Emphasis was focused on liquid–liquid extraction and solid-phase extraction of atrazine and simazine from analysed materials, as well as, on monitoring the content of herbicides and metals in soil and along trophic chain. Higher concentration of pesticides in samples from west region of Poland in comparison to that of east region is likely related to common applying them in Western Europe in relation to East Europe. The content of metals strongly depends on samples origin (industry area, vicinity of motorways).     

Toxicity of nanoparticulate and bulk ZnO, Al2O3 and TiO2 to the nematode Caenorhabditis elegans

Limited information is available on the environmental behavior and associated potential risk of manufactured oxide nanoparticles (NPs). In this research, toxicity of nanoparticulate and bulk ZnO, Al₂O₃ and TiO₂ were examined to the nematode Caenorhabditis elegans with Escherichia coli as a food source. Parallel experiments with dissolved metal ions from NPs were also conducted. The 24-h median lethal concentration (LC₅₀) and sublethal endpoints were assessed. Both NPs and their bulk counterparts were toxic, inhibiting growth and especially the reproductive capability of the nematode. The 24-h LC₅₀ for ZnO NPs (2.3 mg L⁻¹) and bulk ZnO was not significantly different, but significantly different between Al₂O₃ NPs (82 mg L⁻¹) and bulk Al₂O₃ (153 mg L⁻¹), and between TiO₂ NPs (80 mg L⁻¹) and bulk TiO₂ (136 mg L⁻¹). Oxide solubility influenced the toxicity of ZnO and Al₂O₃ NPs, but nanoparticle-dependent toxicity was indeed observed for the investigated NPs.     

新疆克州"十五"期间生态环境质量评价研究

区域生态环境状况对区域经济发展起重要支撑作用,本文采用遥感和地理信息系统的技术手段,利用2000年与2006年ETM影像及CBERS影像,结合《生态环境状况评价技术规范》中的技术方法,对克州"十五"前后生态环境状况进行了综合评价.研究认为,克州总体生态环境状况处于一般和较差水平,"十五"期间克州生态环境状况总体上虽无明显变化,但各生态环境状况评价指数基本上均呈现下降趋势.     

生态围隔对水源地水质的改善效果

采用渔网及土工布挂片双层材料以及填充的水花生构建了生态围隔,对藻类进行拦截,降低取水口藻类密度,同时通过水花生的吸收和拦截,以及土工布挂片形成的附着生物群落的降解和吸收作用,降低颗粒态以及溶解态营养盐,达到取水口水质的改善效果.生态工程实施后,取水口内悬浮颗粒物显著降低了29.8％,同时透明度提高了27.5％.对藻类的拦截效果研究表明,围隔对叶绿素a的去除率为23.0％,对总藻类数量的去除率为20.7％.通过对围隔内外蓝藻数量在藻类数量的比例分析,生态围隔对蓝藻的去除率高于总藻类的去除率,说明了对于藻类拦截的效果具有一定的选择性.对营养盐的改善效果主要体现在颗粒态物质上,其中颗粒态氮磷的去除率分别为48.4％和31.3％.     

辽宁省生态清洁小流域抗生素监测及生态风险评估

于2021年10月对辽宁省生态清洁小流域抗生素的赋存浓度、分布特征进行了调查。采用风险商值法对小流域的抗生素生态风险进行评价。结果表明,辽宁省生态清洁小流域中8种抗生素均有不同程度检出,检出总质量浓度范围为0013～0.313 μg/L,平均值为0.072 μg/L;小流域中抗生素质量浓度均低于我国大部分河流和流域。不同类型抗生素空间分布规律差异明显,检测出的抗生素中,质量浓度最高的是罗红霉素（ROX）,检出率最高的是磺胺甲噁唑（SMX）;各监测点位抗生素组分的占比排序为：SMX＞ROX＞替米考星（TIC）＞氟苯尼考（FFC）;抗生素主要来源是畜禽养殖和生活污水。生态风险评价结果显示,ROX、脱水红霉素（ERY-H₂O）、诺氟沙星（NOR）和SMX存在高风险,其余种类呈现中、低风险。生态清洁小流域水体中暴露出的抗生素生态风险不容忽视,亟待进一步探究环境风险并采取有效的防治措施。     

基于生物导向的水生态健康监测及评估概述

环境监测是水生态健康监测与评估的重要环节,基于物理、化学监测的传统水质监测通常仅能提供独立的数据信息,不能全面、直观地反映水环境状况。基于生物等生命体导向的水生态监测通过生物对环境的响应,能够直接反应复杂水体状况,在水环境健康监测与评估中占据重要地位。基于病原微生物、指示生物介绍了生物监测中的常规生物指标,总结了包括藻类、无脊椎动物和鱼类在内的常见指示生物在不同类型污染水体中的环境指示作用。从生物毒性效应出发介绍了常用的毒性效应测试方法、分析了污染物在不同生物学水平的响应,从而指明生物毒性效应在水环境健康评估中的发展优势。再从生态完整性角度阐述了生态完整性评价的一般方法和新兴分子生物学技术在水生态健康评估中的应用。重点指出环境毒理学和分子生物学在水环境监测的优势,以期为更加科学精确地进行水生态健康监测预警提供支撑。     

金昌市城区土壤重金属空间分布及潜在生态危害评价

通过对金昌市区范围内74处土壤的取样研究分析,结果表明：Cd、Cu、Ni、Pb、Zn5种重金属平均含量均超过当地土壤背景值,其中以Cu和Ni最为显著,其平均含量分别达到430mg／kg和361mg／kg;5种重金属变异系数均较大,其中Cu和Ni变异系数达到了11.5％和12.3％,属强变异性;采用克立格最优内插法得到金昌市表层土壤重金属含量的空间分布图,发现Cu和Ni呈局部污染态势,矿业开采和金属冶炼加工等工业活动是Cu和Ni最大的污染源;Pb、Zn和Cd在整个研究区域内都有积累,工矿活动和交通运输是金昌市Pb、Zn和Cd的共同污染源。潜在生态危害评价结果表明,该地区重金属污染已构成中度生态危害。