近十年鄱阳湖区极端干旱事件频发现象成因初析

近10 a来鄱阳湖区极端干旱事件频发，引起国内外媒体舆论的广泛关注。针对这一情况，运用流域降水、地表蒸散和出湖径流等数据，从流域水量收支平衡的角度，较为系统地分析了导致鄱阳湖区极端干旱事件频发的原因。结果表明，近10 a来鄱阳湖水文干旱起始日期提前，枯水期拉长。虽然干旱持续时间的长短呈现2~3 a的波动，但在总体上呈现逐渐加长的趋势。从流域水分收支的角度来看，近10 a来以水分亏缺为主，流域降水亏缺是基本的致旱因素，流域蒸散量增加则起到一定的增强作用，而出湖径流所起的作用比较复杂，在多数情况下其致旱的影响程度弱于流域降水作用。长江顶托作用强弱变化可以调节流域的水分收支平衡，强化或者减轻湖泊的干旱程度。2003、2004、2007、2008和2009年发生的极端干旱事件主要由流域水分收入项的大幅度减少所造成的，而长江水情变化在多数情况下加剧了流域水分收支的不平衡。这些研究结果明晰了鄱阳湖流域气象干旱与湖泊水文干旱之间的关系以及长江水情变化所扮演的重要角色，为应对未来的干旱变化和制定合理的抗旱防旱对策与措施提供了科学的依据     

湖库泥沙资源化多目标优化配置研究综述

合理利用泥沙的资源特性,实现泥沙资源优化配置是湖库生态环境治理迫切需要解决的关键问题之一。该文旨在对泥沙资源化及多目标优化配置方法的研究进行综述,总结泥沙资源化的研究现状和分析其发展趋势。首先对泥沙资源优化配置框架的相关研究进行了综述,主要集中于泥沙资源优化配置、泥沙资源化的途径、泥沙管理生态化及优化配置方法等方面,然后分析了目前对于泥沙资源优化配置的理论认识、模型构建及应用、方案评价及决策存在的主要问题,最后探讨了泥沙资源优化配置相关研究未来发展方向。     

城市地表水环境质量排名方法研究

基于现行的国家水环境质量评价标准和方法,研究建立了综合反映城市地表水环境质量的城市水质指数CWQI。方法具有普适性、可操作性和可比性,可用于城市地表水环境质量排名。应用于长三角经济圈、珠三角经济圈和京津冀经济圈的相关城市进行排名测算,3个经济圈的城市水质指数呈现不同的分布规律,总体来说长三角经济圈的城市地表水环境质量优于珠三角经济圈和京津冀经济圈。     

Toward better understanding and feasibility of controlling greenhouse gas emissions from treatment of industrial wastewater with activated sludge

Wastewater treatment plants (WWTPs) have been recognized as important sources for anthropogenic greenhouse gas (GHG) emission. The objective of the study was to thoroughly investigate a typical industrial WWTP in southern Taiwan in winter and summer which possesses the emission factors close to those reported values, with the analyses of emission factors, mass fluxes, fugacity, lab-scale in situ experiments, and impact assessment. The activated sludge was the important source in winter and summer, and nitrous oxide (N₂O) was the main contributor (e.g., 57 to 91 % of total GHG emission in a unit of kg carbon dioxide-equivalent/kg chemical oxygen demand). Albeit important for the GHGs in the atmosphere, the fractional contribution of the GHG emission to the carbon or nitrogen removal in wastewater treatment was negligible (e.g., less than 1.5 %). In comparison with the sludge concentration or retention time, adjusting the aeration rate was more effective to diminish the GHG emission in the activated sludge without significantly affecting the treated water quality. When the aeration rate in the activated sludge simulation was reduced by 75 %, the mass flux of N₂O could be diminished by up to 53 % (from 9.6 to 4.5 mg/m²-day). The total emission in the WWTP (including carbon dioxide, methane, and N₂O) would decrease by 46 % (from 0.67 to 0.36 kg CO₂-equiv/kg COD). However, the more important benefit of changing the aeration rate was lowering the energy consumption in operation of the WWTP, as the fractional contribution of pumping to the total emission from the WWTP ranged from 46 to 93 % within the range of the aeration rate tested. Under the circumstance in which reducing the burden of climate change is a global campaign, the findings provide insight regarding the GHG emission from treatment of industrial wastewater and the associated impact on the treatment performance and possible mitigation strategies by operational modifications.

     

Effect of tea saponin on phytoremediation of Cd and pyrene in contaminated soils by <Emphasis Type="Italic">Lolium multiflorum</Emphasis>

Tea saponin (TS), a kind of green biosurfactant produced by plants, was added into the Cd–pyrene co-contaminated soils to evaluate its influence on phytoremediation of Cd and pyrene by Lolium multiflorum. The results showed that the accumulation of pyrene in L. multiflorum was significantly promoted by the TS. Compared with no TS treatments (PL and ML), the aboveground concentrations of pyrene in TS treatments (PLT and MLT) increased by 135 and 30%, respectively, and the underground concentrations of pyrene in TS treatments (PLT and MLT) increased by 40 and 25%. The concentrations of Cd in the aboveground and underground parts in single contaminated treatments were all significantly more than those in co-contaminated treatments, while the situation of pyrene was quite the reverse. Besides, the addition of TS enhanced activities of dehydrogenase and polyphenol oxidase in soils and increased the biomass of L. multiflorum. The micromorphology of L. multiflorum was not affected by TS. The study suggests that the use of L. multiflorum with TS is an alternative technology for remediation of Cd–pyrene co-contaminated soils.     

高氯低COD值水样的无汞快速测定法

以硝酸银和硫酸铬钾代替硫酸汞来消除 COD 测定中的氯离子干扰，同时将重铬酸钾溶液的浓度降低为0.100 mol／L，并用硫磷混酸代替硫酸，该方法经过对标准样品和实际样品的测定，表现出对于测定氯离子含量低于25000 mg／L的高氯低 COD 值水样具有较好的准确度和精密度，同时可以实现银盐的回收再利用。     

Occurrence,sorption, and transformation of free and conjugated natural steroid estrogens in the environment

Environmental Science and Pollution Research - Natural steroid estrogens (NSEs), including free estrogens (FEs) and conjugated estrogens (CEs), are of emerging concern globally among public and...     

Concentrations and accumulation rates of polychlorinated biphenyls in soil along an urban–rural gradient in Shanghai

Environmental Science and Pollution Research - This study proposed an in situ soil experimental system to quantify concentration and accumulation rates of polychlorinated biphenyl (PCB) congeners...     

有机胺调控的CO2吸附材料的研究进展

当前,CO_2排放量急剧增加,空气中CO_2浓度正逐年增大.利用固体材料进行CO_2吸附可以实现CO_2减排的目的.CO_2吸附剂中,有机胺调控的固体材料因具有吸附量较大、对设备腐蚀性较小等特点而备受关注.然而,目前所报道的大部分有机胺调控的固体材料中N原子利用率较低,吸附速率较慢.在CO_2吸附体系中引入水分,使其参与CO_2捕集,有利于提高CO_2与氨基的反应摩尔比,增大N原子利用率,提高CO_2吸附性能.将含羟基的聚合物引入至有机胺调控的CO_2吸附材料之中,也可以获得相似的效果.本文综述了近年来有机胺调控的CO_2吸附材料的设计及"构-效"关系,具体包括有机胺调控的氧化物、多孔碳材料、硅基分子筛和金属-有机框架材料的合成及CO_2吸附机理.同时,展望了有机胺调控的CO_2吸附材料面临的科学挑战及发展机遇.     

Review on China’s wind power policy (1986–2017)

As an important renewable energy source, wind power plays a key role in mitigating climate change and has become one of the fastest growing clean energies globally. In China, wind energy development has been a vital component of national energy transformation strategy. Over the years, the Chinese government has introduced a series of policies to promote the development of wind power and also to regulate this emerging industry. Base on examining all the key policy documents on wind power issued by the Chinese government over the last 30 years, we find that China has built up a comprehensive policy system, and summarized the current framework of Chinese wind power policy systematically. Then, we analyze the policy objectives, policy tools, major measures, their results in each development stage, and the characteristics and trends of China’s wind power policies. Finally, we discuss the limitations of the current policy and put forward corresponding suggestions.