Reduction of copper(II) by iron(II)

Laboratory and field investigations have clearly demonstrated the important role of reduced iron (Fe(II)) in reductive transformations of first-row transition metal species. However, interactions of Fe(II) and copper (Cu) are not clearly understood. This study examined the reduction of Cu(II) by Fe(II) in stirred-batch experiments at pH 5.2 and 5.5 as influenced by chloride (Cl-) concentration (0.002-0.1 M), initial metal concentration (0.1-9.1 mM), and reaction time (1-60 min) under anoxic conditions. Reduction of Cu(II) to Cu(I) by dissolved Fe(II) was rapid under all experimental conditions and the stability of the products explains the driving force for the redox reaction. Under conditions of low [Cl-] and high initial metal concentration, >40% of total Cu and Fe were removed from solution after 1 min, which accompanied formation of a brownish-red precipitate. X-ray diffraction (XRD) patterns of the precipitates revealed the presence of cuprite (Cu2O), a Cu(I) mineral, based on d-spacings located at 0.248, 0.215, 0.151, and 0.129 nm. Fourier transform infrared (FTIR) spectroscopy corroborated XRD data for the presence of Cu2O, with features located at 518, 625, and 698 cm(-1). Increasing [Cl-] stabilized the dissolved Cu(I) product against Cu2O precipitation and resulted in more Fe precipitated from solution (relative to Cu) that appears to be present as poorly crystalline lepidocrocite (gamma-FeOOH). This process may be important in anoxic soil environments, where dissolved Fe(II) levels can accumulate.     

饮用水中嗅味物质-土臭素和二甲基异冰片去除技术

本文介绍了引起饮用水臭味的痕量污染物土臭素（geosmin，GSM）和二甲基异冰片（2-methylisoborneol，MIB）的来源和危害，分析了吸附、臭氧氧化、光催化氧化、生物氧化等工艺对它们的去除效果。针对原水中不同种类和不同浓度的嗅味物质，应采取不同的处理工艺，达到良好的处理效果，满足居民对水质的要求。     

环境保护法规制定程序办法

国家环境保护总局令第25号《环境保护法规制定程序办法》已经2005年4月11日国家环境保护总局局务会议审议通过,现予发布,自2005年6月1日起施行。1990年3月12日国家环境保护局发布的《国家环境保护局法规性文件管理办法》同时废止。国家环境保护总局局长解振华二○○五年四月二十五日主题词:第一章总则第一条为了规范环境保护法规的制定程序,保证立法质量,根据《立法法》、《行政法规制定程序条例》、《部门规章制定程序条例》、《法规部门规章备案条例》和《全面推进依法行政实施纲要》,制定本办法。第二条本办法所称“环境保护法规”,是指…     

Effect of uranium(VI) speciation on simultaneous microbial reduction of uranium(VI) and iron(III)

Uranium is a pollutant of concern to both human and ecosystem health. Uranium's redox state often dictates whether it will reside in the aqueous or solid phase and thus plays an integral role in the mobility of uranium within the environment. In anaerobic environments, the more oxidized and mobile form of uranium (UO2(2+) and associated species) may be reduced, directly or indirectly, by microorganisms to U(IV) with subsequent precipitation of UO. However, various factors within soils and sediments, such as U(VI) speciation and the presence of competitive electron acceptors, may limit biological reduction of U(VI). Here we examine simultaneous dissimilatory reduction of Fe(III) and U(VI) in batch systems containing dissolved uranyl acetate and ferrihydrite-coated sand. Varying amounts of calcium were added to induce changes in aqueous U(VI) speciation. The amount of uranium removed from solution during 100 h of incubation with S. putrefaciens was 77% in absence of Ca or ferrihydrite, but only 24% (with ferrihydrite) and 14% (without ferrihydrite) were removed for systems with 0.8 mM Ca. Dissimilatory reduction of Fe(III) and U(VI) proceed through different enzyme pathways within one type of organism. We quantified the rate coefficients for simultaneous dissimilatory reduction of Fe(III) and U(VI) in systems varying in Ca concecentration (0-0.8 mM). The mathematical construct, implemented with the reactive transport code MIN3P, reveals predominant factors controlling rates and extent of uranium reduction in complex geochemical systems.     

德国斯图加特市污水处理厂污泥焚烧工艺

本文介绍了德国HauptklrwerkStuttgart-Mühlhausen污水处理厂的鼓泡式流化床焚烧炉结构及污泥焚烧工艺流程。     

Degradation of N-nitrosodimethylamine (NDMA) in landscape soils

N-nitrosodimethylamine (NDMA), a potential carcinogen, was commonly found in treated wastewater as a by-product of chlorination. As treated water is increasingly used for landscape irrigation, there is an imperative need to understand the leaching risk for NDMA in landscape soils. In this study, adsorption and incubation experiments were conducted using landscape soils planted with turfgrass, ground cover, and trees. Adsorption of NDMA was negligibly weak (K(d) < 1) in all soils, indicating that NDMA has a high potential for moving with percolating water in these soils. Degradation of NDMA occurred at different rates among these soils. At 21 degrees C, the half-life (t(1/2)) of NDMA was 4.1 d for the ground cover soil, 5.6 d for the turfgrass soil, and 22.5 d for the tree soil. The persistence was substantially prolonged after autoclaving or when incubated at 10 degrees C. The rate of degradation was not significantly affected by the initial NDMA concentration or addition of organic and inorganic nutrient sources. The relative persistence was inversely correlated with soil organic matter content, soil microbial biomass, and soil dehydrogenase activity, suggesting the importance of microorganisms in NDMA degradation in these soils. These results suggest that the behavior of NDMA depends closely on the vegetation cover in a landscape system, and prolonged persistence and increased leaching may be expected in soils with sparse vegetation due to low organic matter content and limited microbial activity.     

2007年全国环境统计公报

2007年,在党中央、国务院的正确领导下,各地区、各部门深入贯彻落实科学发展观,把污染减排作为一项重要任务,采取综合措施,加快污染治理,推动力度进一步加大,政策措施进一步落实,化学需氧量和二氧化硫排放量实现双下降,环保工作取得积极进展.     

微网动态膜生物反应器的研究进展

对微网动态膜生物反应器进行了较为全面的综述,在简要介绍动态膜过滤技术的基础上,对DMBR处理生活污水的运行处理效果、生物动态膜特性、DMBR结构改进及其应用的扩展研究等方面做了介绍,分析了目前该工艺存在的生物动态膜机理研究不透彻、运行稳定性较差、对工业废水的处理研究较少等问题,展望了该工艺的研究方向,即反应器结构的改进、生物动态膜地位与功能的解析、及应器优化控制研究等。     

From eco-management and audit (EMAS) to sustainability management and audit (SMAS)

The local authority version of the Eco-Management and Audit Scheme (LA-EMAS) can already be used as a tool for managing towards sustainability. But it can also be used in a much less ambitious 'procedural' way. This article suggests how LA-EMAS could be developed more fully into a sustainability management tool embracing social issues, a concern over environmental carrying capacities, and stakeholder involvement. This raises questions which should be considered in the run-up to the review of the EMAS regulation in 1998.     

气候(温度/湿度)和力学动态(振动/冲击)组合试验

在汽车、轨道交通和空间领域都存在温度、湿度和振动或冲击的组合环境。通过实验室内受控地在参量范围内模拟环境下暴露样品进行评估。用严酷的环境参量强化试验,通常可在相对较短的时间内获得有效的结果。     

Evaluation of Electromagnetic Fields (EMF) in Schools in Cyprus

Summary This paper deals with the evaluation of Extremely Low Frequency (ELF) Electromagnetic Fields (EMF) produced by high tension wires on pylons and substations, which were preliminarily investigated by taking measurements in schools (on behalf of the Environmental Committee of Limassol). It publicizes the level of EMF from the above sources and makes an attempt to compare them with various exposure limits. Finally, certain measures to be taken by the responsible authorities are suggested, as possible actions aiming at the protection of the Cypriot people from any EMF health risk.     

Sustainability and emerging issues in scholarly (self-)publishing

In American academic circles, peer-reviewed hard-copy book publishing remains a crucial part of the tenure and promotion process as well as a method of bestowing prestige upon authors accepted by university presses and other mainstream venues. Although a few respected individuals self-published as early as the seventeenth century, the emergence of desktop publishing during the 1980s led to hard-copy and virtual (self-)publishing venues of several kinds, including PDF formatting and the establishment of POD (print on demand) firms. Online, PDF, POD printing, and other challenges to traditional academic publishing can save money and improve efficiency as well as help sustain our forests and other natural resources.     

Land-use dynamics in a southern Illinois (USA) watershed

The Cache River of southernmost Illinois is used as a case study for developing and demonstrating an approach to quantitatively link (1) national agricultural policy and global agricultural markets, (2) landowner's decisions on land use, (3) spatial patterns of land use at a watershed scale, and (4) hydrologic impacts, thus providing a basis to predict, under a certain set of circumstances, the environmental consequences of economic and political decisions made at larger spatial scales. The heart of the analysis is an estimation, using logistic regression, of the affect of crop prices and Conservation Reserve Program (CRP) rental rates on farmland owner's decisions whether to reenroll in the CRP or return to crop production. This analysis shows that reasonable ranges for crop prices (80%–150% of 1985–1995 values) and CRP rental rates (0–125% of 1985–1995 rates) result in a range of 3%–92% of CRP lands being returned to crop production, with crop prices having a slightly greater effect than CRP rental rates. Four crop price/CRP rental rate scenarios are used to display resulting land-use patterns, and their effect on sediment loads, a critical environmental quality parameter in this case, using the agricultural non point source (AGNPS) model. These scenarios demonstrate the importance of spatial pattern of land uses on hydrological and ecological processes within watersheds. The approach developed can be adapted for use by local governments and watershed associations whose goals are to improve watershed resources and environmental quality.     

Loss pathways of N-nitrosodimethylamine (NDMA) in turfgrass soils

N-nitrosodimethylamine (NDMA) is a potent carcinogen that is often present in municipal wastewater effluents. In a previous field study, it was observed that NDMA did not leach through turfgrass soils following 4 mo of intensive irrigation with NDMA-containing wastewater effluent. To better understand the loss pathways for NDMA in landscape irrigation systems, a mass balance approach was employed using in situ lysimeters treated with 14C-NDMA. When the lysimeters were subjected to irrigation and field conditions after NDMA application, very rapid dissipation of NDMA was observed for both types of soil used in the field plots. After only 4 h, total 14C activity in the lysimeters decreased to 19.1 to 26.1% of the applied amount, and less than 1% of the activity was detected below the 20-cm depth. Analysis of plant materials showed that less than 3% of the applied 14C was incorporated into the plants, suggesting only a minor role for plant uptake in removing NDMA from the vegetated soils. The rapid dissipation and limited downward movement of NDMA in the in situ lysimeters was consistent with the negligible leaching observed in the field study, and suggests volatilization as the only significant loss pathway. This conclusion was further corroborated by rapid NDMA volatilization found from water or a thin layer of soil under laboratory conditions. In a laboratory incubation experiment, prolonged wastewater irrigation did not result in enhanced NDMA degradation in the soil. Therefore, although NDMA may be present at relatively high levels in treated wastewater, gaseous diffusion and volatilization in unsaturated soils may effectively impede significant leaching of NDMA, minimizing the potential for ground water contamination from irrigation with treated wastewater.     

房地产交易(环境)审计--污染现场/土地环境评估

本文介绍了现今发达国家实施的房地产交易(环境)审计,以期推进房地产交易审计在国内实施。     

Kinetic of carbonaceous substrate in an upflow anaerobic sludge sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP)

The performance of an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP) was evaluated at different hydraulic retention times (HRTs) using synthetic wastewater in order to obtain the growth substrate (glucose-COD) and 2,4 DCP removal kinetics. Treatment efficiencies of the UASB reactor were investigated at different hydraulic retention times (2-20 h) corresponding to a food to mass (F/M) ratio of 1.2-1.92 g-COD g(-1) VSS day(-1). A total of 65-83% COD removal efficiencies were obtained at HRTs of 2-20 h. In all, 83% and 99% 2,4 DCP removals were achieved at the same HRTs in the UASB reactor. Conventional Monod, Grau Second-order and Modified Stover-Kincannon models were applied to determine the substrate removal kinetics of the UASB reactor. The experimental data obtained from the kinetic models showed that the Monod kinetic model is more appropriate for correlating the substrate removals compared to the other models for the UASB reactor. The maximum specific substrate utilization rate (k) (mg-COD mg(-1) SS day(-1)), half-velocity concentration (K(s)) (mg COD l(-1)), growth yield coefficient (Y) (mg mg(-1)) and bacterial decay coefficient (b) (day(-1)) were 0.954 mg-COD mg(-1) SS day(-1), 560.29 mg-COD l(-1), 0.78 mg-SS g(-1)-COD, 0.093 day(-1) in the Conventional Monod kinetic model. The second-order kinetic coefficient (k(2)) was calculated as 0.26 day(-1) in the Grau reaction kinetic model. The maximum COD removal rate constant (U(max)) and saturation value (K(B)) were calculated as 7.502 mg CODl(-1)day(-1) and 34.56 mg l(-1)day(-1) in the Modified Stover-Kincannon Model. The (k)(mg-2,4 DCP mg(-1) SS day(-1)), (K(s)) (mg 2,4 DCPl(-1)), (Y) (mg SS mg(-1) 2,4 DCP) and (k(d)) (day(-1)) were 0.0041 mg-2,4 DCP mg(-1) SS day(-1), 2.06 mg-COD l(-1), 0.0017 mg-SS mg(-1) 2,4 DCP and 3.1 x 10(-5) day(-1) in the Conventional Monod kinetic model for 2,4 DCP degradation. The second-order kinetic coefficient (k(2)) was calculated as 0.30 day(-1) in the Grau reaction kinetic model. The maximum 2,4 DCP removal rate constant (U(max)) and saturation value (K(B)) were calculated as 0.01 mg COD l(-1) day(-1) and 9.8 x 10(-3) mg l(-1) day(-1) in the Modified Stover-Kincannon model.