Photochemical properties and source of pollutants during continuous pollution episodes in Beijing, October, 2011

Beijing sufered from serious air pollution in October, 2011 with the occurrence of three continuous episodes. Here we analyze the pollution status of particulate matter, the relationship between the gaseous pollutants, physical and chemical properties of single particles, and the profile of watersoluble ions in PM2.5during the three episodes. Regional and photochemically aged air masses, which were characterized as having high values of O3and SO2, were hypothesized to have played a dominant role in the first episode. After mixing local air masses with freshly-emitted primary pollutants, the concentration of NOx continued to increase and the size of SO4 2, NO3 and NH4 +in the particle population continued to become smaller. The amount of elemental carbon-rich and organic carbonrich particles in the scaled single particles(0.2–2 μm) and water-soluble K+in PM2.5also increased in the episodes. All the available information suggests that the biomass or fuel burning sources in or around Beijing may have had a huge impact on the last two episodes.     

北京市典型城区环境空气中苯系物的污染特征、来源分析与健康风险评价

自2013年6月以来,利用Airmo VOC在线分析仪在北京市典型城区开展了环境空气中挥发性有机物(VOCs)的连续观测,选取2014年4个季节中各1个月的苯系物在线数据,分析了其浓度水平、变化特征、光化学反应活性,利用美国环保署(US EPA)提出的健康风险评价方法开展了有毒有害苯系物物种的健康风险评价,结合来源分析结果,明确北京市应重点控制的苯系物污染来源。研究区观测期间环境空气中16种苯系物的质量浓度为(22.64±16.83)μg·m-3,且具有秋季冬季春季夏季的特点,其中BTEX(苯、甲苯、乙苯和二甲苯)的质量浓度为(19.27±14.46)μg·m-3,占苯系物浓度水平的41.09%~95.16%。研究区观测期间苯系物质量浓度夜间高于日间,日变化呈V字形,在13:00—15:00时质量浓度低。16种苯系物的臭氧生成潜势(OFP)的范围为66.62~170.67μg·m-3,其中间+对二甲苯、甲苯和邻二甲苯的OFP值相对较大;二次有机气溶胶生成潜势(SOAFP)的范围为0.71~1.86μg·m-3,其中甲苯、间+对二甲苯和乙苯的SOAFP值相对较大。研究区观测期间6种苯系物(BTEX和苯乙烯)的危害指数在8.19E-03~5.01E-02之间,在4个季节中对暴露人群尚不存在非致癌性风险;而Ⅰ类致癌物质苯的风险值处于7.13E-08~8.13E-06之间,在夏、秋和冬季对研究区暴露人群的人体健康均存在潜在的致癌性风险。来源分析结果表明,研究区春、秋季苯系物主要来源于机动车尾气的排放,其中春季还受到溶剂等挥发的影响,夏、冬季苯系物则主要来自于燃煤源。     

Conversion relationship between groundwater and surface water in the Taizi River Basin in China based on geochemical and isotopic characteristics

Environmental Science and Pollution Research - Stable isotopes (δDVSMOW and δ18OVSMOW) and hydrochemical characteristics were analyzed to determine the groundwater and surface water...     

A comparative study of abiological granular sludge (ABGS) formation in different processes for zinc removal from wastewater

Abiological granular sludge (ABGS) formation is a potential and facile strategy for improving sludge settling performance during zinc removal from wastewater using chemical precipitation. In this study, the effect of pH, seed dosage, and flocculant dosage on ABGS formation and treated water quality was investigated. Results show that settling velocity of ABGS can reach up to 4.00 cm/s under optimal conditions, e.g., pH of 9.0, zinc oxide (ZnO) seeds dosage of 1.5 g/l, and polyacrylamide (PAM) dosage of 10 mg/l. More importantly, ABGS formation mechanism was investigated in NaOH precipitation process and compared with that in bio-polymer ferric sulfate (BPFS)–NaOH precipitation process regarding their sludge structure and composition. In the NaOH precipitation process, ABGS formation depends on some attractions between particles, such as van der Waals attraction and bridging attraction. However, during the BPFS–NaOH sludge formation process, steric repulsion becomes dominant due to the adsorption of BPFS on ZnO seeds. This repulsion further causes extremely loose structure and poor settling performance of BPFS–NaOH sludge.     

Study on the optical property and surface morphology of N doped TiO2 film deposited with different N2 flow rates by DCPMS

N doped TiO₂ films were deposited by direct current pulse magnetron sputtering system at room temperature. By using UV-Vis spectrophotometer and atomic force microscope, we studied the influence of N₂ flow rate on the optical property and surface morphology of films. The results indicate that the optical property and surface morphology of N doped TiO₂ film was dominated by the N₂ flow rate. The mean absorbency in visible range of pure TiO₂ films is near to 0%, which means that the pure TiO₂ could hardly display the photocatalytic property in visible range. When N₂ flow rate is 2 sccm, the mean absorbency in visible range of N doped TiO₂ film could reach at 24%. In this case, the film could be used as photocatalyst induced by visible light. While with increasing N₂ flow rate, the mean absorbency in visible range of N doped TiO₂ film decreased abruptly. Especially when N₂ flow rate exceeded 8 sccm, the mean absorbency in visible range of N doped TiO₂ film decreased to about 0%, which is like pure TiO₂ fimls.     

Study on the optical property and surface morphology of N doped TiO2 film deposited with different N2 flow rates by DCPMS

N doped TiO₂ films were deposited by direct current pulse magnetron sputtering system at room temperature. By using UV-Vis spectrophotometer and atomic force microscope, we studied the influence of N₂ flow rate on the optical property and surface morphology of films. The results indicate that the optical property and surface morphology of N doped TiO₂ film was dominated by the N₂ flow rate. The mean absorbency in visible range of pure TiO₂ films is near to 0%, which means that the pure TiO₂ could hardly display the photocatalytic property in visible range. When N₂ flow rate is 2 sccm, the mean absorbency in visible range of N doped TiO₂ film could reach at 24%. In this case, the film could be used as photocatalyst induced by visible light. While with increasing N₂ flow rate, the mean absorbency in visible range of N doped TiO₂ film decreased abruptly. Especially when N₂ flow rate exceeded 8 sccm, the mean absorbency in visible range of N doped TiO₂ film decreased to about 0%, which is like pure TiO₂ fimls.     

太湖流域地区开展农村环境连片整治的探索

农村环境连片整治以解决区域性突出环境问题为目的,对地域空间上相对聚集在一起的多个村庄实施同步、集中整治是使环境问题得到有效解决的治理方式。本文阐述了农村环境问题的现状及开展农村环境保护的背景,从农村环境连片整治的特点出发,以常州武进区雪堰镇农村环境综合整治示范点成功开展整治工作为例,进行太湖流域地区开展农村环境连片整治的探索,并总结了在太湖流域地区成功开展农村环境连片整治的建议及农村环保工作的导向。     

安太堡露天矿排土场表层岩土的径流特征与复垦种植研究

采用针孔式小型人工降雨机,分别模拟山西塞北高原90～60min,60～45min,45～30min,30～15min各时段降水量极大值,探讨大型露天矿排土场各种排土工艺下地表岩土的径流特征,以指导排土工艺和复垦种植。     

微量金属对废水厌氧处理效果的影响

以葡萄酒蒸馏废水的厌氧生物处理为例,研究了Fe、Ni、Co、Mo、Cu、Zn对厌氧反应器的COD去除率、出水中挥发性有机酸含量、气体产量、气体成分、pH缓冲能力和碱度等的影响.对比了微量金属投加前后,厌氧反应器污泥中微量金属含量的变化.得出微量金属具有提高厌氧运行效果的作用,其中,Co的作用要更大一些.Ni、Co、Mo在附着态、悬浮态污泥中具有逐渐积累的特点;Fe、Cu、Zn在附着态污泥中是淋失的,而在悬浮态污泥中变化不大.