S–O–C isotopic picture of sulphate–methane–carbonate system in freshwater lakes from Poland. A review

Microbial oxidation of organic compounds (including methane), in freshwater sediments, may result in precipitation of carbonates, which may become an important geochemical archive of paleoenvironmental variations. Most probably low δ¹³C value in calcite in eutrophic systems results from an advanced oxidation of organic compounds in turbulent or/and sulphate-rich conditions. Likewise, high δ¹³C value in calcite from organic-rich sediments may evidence low redox potential of the freshwater system. Oxidation of methane and organic matter results in significant isotope effects in sulphates dissolved in water. Therefore, to better understand the origin of carbon isotope signal in carbonates, concentration and stable isotope measurements in dissolved sulphate (water column), bubble methane and calcite (freshwater sediments) have been carried out in 24 lakes, 2 ponds and 4 rivers in Poland. The highest concentration of sulphate has been detected in rivers (85.47 SO₄ ²⁻ mg/l) and an artificial lake (70.30 SO₄ ²⁻ mg/l) located in the extremely SO₄ ²⁻-polluted region called the “Black Triangle”. The lowest concentration of sulphate is found in dystrophic and mountain lakes (from 0.5 SO₄ ²⁻ to about 3 mg/l). The lowest δ³⁴S(SO₄ ²⁻) and δ¹⁸O(SO₄ ²⁻) values occur in unpolluted lakes in eastern Poland (−0.94 and 1.38‰, respectively). The highest S and O isotopic ratios are found in a polluted lake in western Poland (δ¹⁴S(SO₄ ²)=12.95‰) and in a dystrophic lake in eastern Poland (δ¹⁸O(SO₄ ²) = 16.15‰) respectively. It is proposed that δ³⁴SO₄ ²⁻ and (¹⁸O(SO₄ ²⁻) values in lakes represent a good tool to assess and quantify anthropogenic impact by acid precipitation and to monitor variations in the trophic state and redox processes controlled by biodegradation of organic compounds in sediments and water column. In general, increasing depth (up to 12 m) of the water column is associated with decreasing trend the δ¹³C(CH₄) value from about –35 to about –78‰. However, δ¹³C value in sedimentary calcite (δ¹³C vary from –10 to 0.5‰) shows opposite trends as compared to the corresponding methane. This is probably due to redox processes and distribution of heavy isotopes between methane and calcite. Likewise, turbulent water (river) show high δ¹³C value in methane and low δ¹³C value in calcite—this is probably due to an enhanced oxidation of methane producing ¹³C-depleted CO₂. In contrast to clean lakes, it is observed that an increase of the δ¹³C(CH₄) value occurs with increasing depth of the water column in a strongly SO₄ ²⁻-contaminated lake. This is probably due to a loss of biological buffering potential of the lake accompanied by an active oxidation of methane precursors.     

循环经济和工业生态效率指标体系

首先介绍了在OECD国家应用较多的生态效率的概念，并提出目前大力推行的循环经济的本质就是提高生态效率。为了衡量和评价循环经济的发展，有必要研究探索循环经济评价指标体系，本文借鉴生态效率指标体系的内容，对循环经济的评价指标体系进行了初步研究和设计。     

The role of root organic acids in the tolerance of Festuca rubra to zinc,lead and cadmium

Abstract

Festuca rubra L. plants are pseudometallophytes colonizing abandoned Pb/Zn mine areas, successfully employed in phytostabilization. To study the contribution of low-molecular weight organic acids to metal tolerance, F. rubra plants were grown for three months in hydroponics with Cd (1.8, 18 and 36 µmol?L^?1), Pb (50, 250 and 500?µmol?L^?1) and Zn (0.3, 3 and 6?mmol?L^?1), separately, and in ternary combination (18?µmol?L^?1 Cd + 250?µmol?L^?1 Pb + 0.3?mmol?L^?1 Zn). The roots retained most of the metals but their distribution from shoot to root was altered when the plants were treated with the ternary combination. The main organic acids in roots were citrate and malate. At the lowest concentrations, the metals caused small reductions in biomass, had no effects on photosynthetic pigments nor on malondialdehyde, but led to increases in root organic acids. At higher concentrations, phytotoxic responses were observed, associated with a decline of citrate and malate in the roots.     

Assessing the risk of soil contamination in the Swiss Jura using indicator geostatistics

The probability that the concentrations of toxic substances in soil or other medium exceed tolerablemaxima at any unsampled place can be estimated by indicator geostatistics. The method is developed and used to estimate and map the risk of contamination by cadmium, copper and lead in the topsoil of a 14.5 km 2 region in the Swiss Jura. It combines both direct measurements of metal concentrations and thecalibration of a geological map, and it shows that the risk of toxicity is least on Argovian rocks. Two approaches are proposed to divide a region into safe' and 'hazardous' zones on the basis of probability maps. The first declares as contaminated all places where the risk of contamination exceeds a given threshold. The second approach first evaluates the financial costs that might result from a wrongdeclaration, after which the site is allocated to a class so as to minimize that cost. The risk of exposure for humans and animals is generally greater for contaminated agricultural land than for forest soil, and so land use is taken into account in both procedures.     

基于监测样本信息的水环境系统权重分配方法

针对水环境系统权重分配问题，从建筑系统客观背景入手，以环境因子监测样本资料为信息源，通过构造关联信息矩阵，并采用旋转正交转变换的主成分分析法，定量地描述了交五因子在整体系统的贡献，最后依贡献量大小识别对应各个因子的权重值，实例表明，该方法物理意义清晰结果客观合理。     

土地利用规划环境影响评价——以双流县为例

土地利用规划对社会经济的发展和生态环境都会产生深刻的影响，尽早开展其环境影响评价对于保证决策的正确性是十分必要的。文章介绍了土地利用规划环境影响评价的基本程序和内容，提出了一系列的评价原则，分析了与其他环境影响评价的关系。并以双流县为例进行了分析。     

规划环境影响评价指标体系的建立与应用

以沈阳市浑南新区规划为案例,研究和探讨了规划环境影响评价指标的确定原则、理论依据、方法和程序,建立了以目标层、准则层、指标层三个层次,包括社会生态、经济生态、环境生态和环境资源支撑四大类三十项指标构成的规划环境影响评价指标体系,利用这三十项评价指标对规划进行了定量评价。     

工程对环境影响系统分析中有关二次影响问题的探讨

就水电工程对生态与环境二次影响问题的系统分析,提出一种便于应用的交互矩阵方法,并讨论了二次影响程度如何在度量规范中进行追加计算。     

关于我国环境影响评价发展与完善的思考

从可持续发展的角度分析了我国目前环境影响评价工作的现状及存在的问题 ,并从法规、管理、技术、评价范围、程序等多个方面提出了针对性建议。     

城市高架快速路交通噪声的环境影响及防治对策

以青岛市火车站至福州路高架快速路拟建工程为例，分析了城市高架快速路交通噪声对环境的影响，并提出交通噪声防治的对策。