A combined radical and non-radical oxidation processes for efficient degradation of Acid Orange 7 in the homogeneous Cu(II)/PMS system: important role of chloride

Environmental Science and Pollution Research - Trace copper ion (Cu(II)) in water and wastewater can trigger peroxymonosulfate (PMS) activation to oxidize organic compounds, but it only works under...     

水中氰化物突发性污染事故应急监测方法研究

旨在研究现场快速测定水中的氰化物。运用比色分析的朗伯 比尔定律和真空工艺设计 ,将复杂繁琐的实验室测试方法和操作程序有机地融合在测试管中。该测试管具有快速、简便和价格低廉等特点 ,测定范围为 0 0 0 5— 0 2 0mg/L。     

Mercury pollution in a mining area of Guizhou,China: Fluxes over contaminated surfaces and concentrations in air,biological and geological samples

A dynamic flux chamber has been used to estimate fluxes of mercury over different types of surfaces in an abandoned open‐cut mine of Tongren prefecture, Guizhou province, China during spring and summer of 1996. The highest fluxes were obtained over cinnabar slag and contaminated soils, whereas the emissions above cinnabar ore were substantially lower. These fluxes was scaled up to estimate the contribution of mercury emissions to air from mercury wastes, compared to anthropogenic activities in the province of Guizhou, China. Atmospheric mercury concentrations measured were enhanced in the mining area (<1.3 μg m^‐3) compared to regional background sites (1.8–5.1 ng m^‐3). The spreading of mercury was estimated by using biological and geological samples. Moss bags have been employed to estimate long‐time dry‐ and wet‐deposition to this area.     

Structural effect on photocatalytic degradation of metallised azo dyes in aqueous TiO2 suspension

Three metallised azo dyes were investigated under TiO₂‐photocatalytic and photosensitised conditions in aqueous buffering solutions. The degradation follows apparent first‐order kinetics. The size and strength of intramolecular conjugation determine the light‐fastness of the investigated dyes. Compared with ¹O₂ produced in photosensitised process, the more powerful *OH radicals in TiCO₂ photocatalytic process are highly reactive towards the investigated azo dyes. And as a result, the TiO₂‐photocatalysis makes little less distinction in the degradation kinetic data of the azo dyes compared with the photosensitised degradation of them.     

A GIS-based moving window analysis of landscape pattern in the Beijing metropolitan area,China

Quantifying landscape pattern and its change is essential for monitoring and assessment of ecological consequences of urbanization. Using the GIS-based land-use data for 2002, we combined moving window analysis along an urban-rural gradient and around the urban centre with landscape metrics to quantify the spatial pattern of urbanization in Beijing. The results of moving window analysis along the urban-rural gradient indicated that, for class-level metrics, the spatial pattern of urbanization could be quantified using landscape metrics, different land-use types exhibited distinctive spatial signatures, and, for landscape-level metrics, the increase in urbanization in the metropolitan Beijing region has resulted in dramatic increases in patch density (PD), edge density (ED), and patch and landscape shape complexity, and sharp decreases in the largest and mean patch size (MPS), agriculture land-use type, and landscape connectivity. The results of moving window analysis around the urban centre showed that the direction of urbanization could be quantified using the class-level metrics, and landscape-level metrics indicated similar results to gradient analysis. In general, moving window analysis showed that the increasingly urbanized landscape became compositionally more diverse, geometrically more complex, and ecologically more fragmented.     

太湖水体中5种有机磷农药混合物生态风险评价

有机磷农药是一类广泛分布于我国水环境中的污染物,即使在水体中的污染水平处于规定“安全标准”之下,其联合暴露产生的风险仍有可能威胁水生生态安全。采用基于浓度加和模型与生物敏感度分布曲线的混合物风险商法,评价了太湖水体中敌敌畏、对硫磷、甲基对硫磷、马拉硫磷和乐果5种有机磷农药混合物产生的生态风险。结果表明：2003～2004年期间3个不同时期太湖水体中5种有机磷农药的混合物生态风险商(RQ_m )均大于1,有机磷农药混合物在2003～2004年期间对太湖水生生物构成了一定威胁。     

酸胁迫对铜藻早期生长阶段的影响

为探究低pH胁迫对大型藻类早期生长的影响,以铜藻 Sargassum horneri 为研究对象,设置pH=3.5、4.5、5.5、6.5处理组和自然海水对照组,以不同处理时间分别对铜藻孢子和幼体进行胁迫实验。孢子实验中,于铜藻孢子附着前、后对其进行15、30、60、120 min的酸胁迫,以附着率和脱落率表征低pH对孢子附着的影响;幼体实验中,持续将铜藻幼体暴露于酸性条件下,以脱落死亡率表征pH对幼体的致死效应。结果显示,在短时间酸胁迫下,酸度对铜藻孢子附着的影响显著,附着率随pH值的下降而降低;胁迫时间对孢子的附着影响显著,附着率随胁迫时间的延长而降低,pH值与胁迫时间无交互作用;而当孢子已充分附着后,短期酸胁迫并没有显著影响孢子体的存活。在长时间酸胁迫下,与对照组相比,所有处理组铜藻幼体的存活率均显著降低。研究表明,低pH会对铜藻孢子、幼体的存活生长产生不利影响,并且这种影响在铜藻早期发育的不同阶段有所不同。     

Substance flow analysis for an urban drainage system of a representative hypothetical city in China

This paper discusses the use of substance flow analysis (SFA) as a tool to support quantified research on urban drainage systems. Based on the principle of mass balance, a static substance flow model is established to describe and examine the routes and intensities of water, chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) for a representative hypothetical city (RH city) in China, which is a devised and scaled city using statistical characteristics of urban circumstances at the national level. It is estimated that the annual flux of water, COD, TN and TP through the urban drainage system in 2010 was 55.1 million m³, 16037.3 t, 1649.5 t and 209.7 t, respectively. The effluent of wastewater treatment plant (WWTP) was identified as the most important pathway for pollutant emissions, which contributed approximately 60% of COD, 65% of TN and 50% of TP to receiving water. During the wastewater treatment process, 1.0 million m3, 7042.5 t, 584.2 t and 161.4 t of the four studied substances had been transmitted into sludge, meanwhile 3813.0 t of COD and 394.0 t of TN were converted and emitted to the atmosphere. Compared with the representative hypothetical city of 2000, urban population and the area of urban built districts had expanded by approximately 90% and 80% respectively during the decade, resulting in a more than threefold increase in the input of substances into the urban drainage system. Thanks to the development of urban drainage systems, the total loads of the city were maintained at a similar level.     

The abatement of major pollutants in air and water by environmental catalysis

This review reports the research progress in the abatement of major pollutants in air and water by environmental catalysis. For air pollution control, the selective catalytic reduction of NO _x (SCR) by ammonia and hydrocarbons on metal oxide and zeolite catalysts are reviewed and discussed, as is the removal of Hg from flue gas by catalysis. The oxidation of Volatile organic compounds (VOCs) by photo- and thermal-catalysis for indoor air quality improvement is reviewed. For wastewater treatment, the catalytic elimination of inorganic and organic pollutants in wastewater is presented. In addition, the mechanism for the procedure of abatement of air and water pollutants by catalysis is discussed in this review. Finally, a research orientation on environment catalysis for the treatment of air pollutants and wastewater is proposed.     

水体沉积物质量基准研究现状

沉积物质量基准是对水质基准的补充,对水质管理具有重要意义。目前国际上沉积物质量基准计算方法有十几种。对各种方法的理论基础、数据需求、适用范围等方面进行了概述之后,综合分析了各种方法的理论基础。研究结果认为,应将建立沉积物质量基准的方法分为以生物效应数据为基础的生物效应数据库法和以相平衡分配原理为依据的相平衡分配法。而根据统计方法不同,生物效应数据库法又分为单值基准、双值基准和三轴图法。同时还对美国、加拿大、荷兰、英国、澳大利亚和新西兰的沉积物质量基准研究发展和应用概况进行了分析。结合我国实际情况认为,依赖于大量生物效应数据的生物效应数据库法,目前在我国的适用范围有限,只能用于推导少数几种污染物的基准值。相平衡分配法具有可靠的理论基础而且不需要大量的生物效应数据,具有很大的发展潜力。因此,对于目前沉积物质量基准研究处于初级阶段的我国,更适合使用相平衡分配法计算污染物沉积物质量基准。