基于质子微探针研究的大气气溶胶单颗粒源解析

用高分辨率,高灵敏度的质子微探针对上海市人民公园大气气溶胶进行单颗粒源解析.结果发现,上海市大气主要污染源为土壤扬尘、建筑扬尘、汽车尾气和钢铁工业尘,它们对大气环境贡献率之和为80%以上.此外还发现约有13%的颗粒物无法识别,通过对这些颗粒物进行聚类分析,初步确定它们分属于2种不同污染源的亚类和一种新的未知的污染源.     

2种茶树对铜胁迫的响应及其组织铜化学形态变化的比较研究

为了分析不同茶树对Cu胁迫的生理响应及其组织中不同化学形态Cu的累积特性,本研究采用水培法,探讨铁观音、肉桂2种茶树在不同浓度Cu胁迫下,茶树根系活力、叶绿素含量、茶树组织Cu含量及不同化学形态Cu含量的变化,以期为重金属对茶树毒害机理和茶树对重金属的自我防御研究提供理论依据。结果表明,随着Cu胁迫浓度的增加,茶树根系活力及叶片叶绿素含量呈现下降趋势,而与对照相比,铁观音下降的幅度远高于肉桂。不同茶树品种在相同浓度Cu胁迫下,其根、茎、叶组织的Cu含量差异不显著,而不同组织中则表现为根叶茎。不同化学形态Cu含量分析结果表明,随着Cu胁迫浓度的升高,2种茶树根部可交换态Cu、碳酸盐结合态Cu、有机结合态Cu含量百分比呈现下降趋势,而铁锰氧化态Cu和残留态Cu呈现上升趋势;茎部可交换态Cu、有机结合态Cu含量百分比呈现下降趋势,碳酸盐结合态Cu、铁锰氧化态Cu和残留态Cu呈现上升趋势;叶部可交换态Cu、碳酸盐结合态Cu、有机结合态Cu含量、铁锰氧化态Cu含量的百分比均呈现上升趋势,而残留态Cu呈现下降趋势。进一步分析发现,Cu胁迫下,铁观音茶树根、叶部主要以采取提高有机结合态Cu的形式来降低Cu离子毒害,而肉桂则以提高铁锰氧化态Cu形式降低Cu离子毒害,叶部则以提高铁锰氧化态Cu和残留态Cu的形式降低Cu离子毒害。可见,不同的茶树在Cu胁迫下所表现解毒模式存在着一定的差异。     

混凝+厌氧+好氧组合工艺处理油墨废水的工程实例

采用混凝沉淀+水解酸化池+BIOFOR滤池工艺对文具厂油墨废水进行处理,通过工程实例,对工艺流程,构筑物的设计参数,调试运行进行探讨。结果表明:对于COD较大,色度非常高的油墨废水经该工艺处理后,能达到GB8978-1996《废水综合排放标准》中一级排放标准,且该工程投资小,运行费用低;管理简单方便。     

常用城市污水再生处理工艺净化效果比较分析

以城市污水回用为目的,对常规混凝-沉淀-过滤工艺、臭氧生物活性炭和直接超滤等深度处理技术处理城市污水处理厂二级出水的效果进行了试验研究,对各种工艺的去除效果进行了评价。     

不同干燥处理对城市污泥物理性质和农业利用的影响

城市污泥农用正在成为世界各国处置污泥的主要方式之一,但干燥后的污泥通常结块程度高,硬度大,较难粉碎,对污泥的后续利用产生影响.试验设置了露天、棚内浇水和棚内不浇水等三个不同的污泥干燥处理,试验结果表明,露天状态处理干燥后的污泥要明显松散,结块程度较低;露天状态处理干燥后,粒径在5～10 mm和小于5 mm的污泥颗粒含量要显著高于棚内浇水和棚内不浇水处理,且露天处理干燥后污泥中水稳性团聚体所占比例最大,小于0.001 mm的粒级(粘粒)所占比例最小,不易造成土壤板结.因此,露天处理干燥后的城市污泥对农用较为有利.     

Simultaneous photocatalytic reduction of Cr(VI) and oxidation of phenol over monoclinic BiVO4 under visible light irradiation

BiVO4 powder with monoclinic structure was prepared and used as a visible-light catalyst simultaneously for the photooxidation of phenol and the photoreduction of Cr(VI). The photocatalytic efficiency was found to be rather low for either single phenol solution or single Cr(VI) solution. However, the photocatalytic reduction of Cr(VI) and photocatalytic oxidation of phenol proceed more rapidly for the coexistence system of phenol and Cr(VI) than for the single process, showing synergetic effect between the oxidation and reduction reactions. For the simultaneous photocatalytic reduction-oxidation process, the first-order kinetic constant of phenol degradation was 0.0314 min-1, being about six times higher than that for the photocatalytic process of single phenol. This result reveals the feasibility of using Cr(VI) as the electron scavenger of mBiVO4-mediated photocatalytic process of phenol degradation, and gives us an enlightenment to employ other semiconductor with a better visible light response but with a more positive band edge to efficiently degrade organic pollutants. This is the first report for simultaneous photocatalytic reduction of Cr(VI) and removal of phenol under visible light irradiation using photocatalyst mBiVO4.     

Joint anti-estrogenic effects of PCP and TCDD in primary cultures of juvenile goldfish hepatocytes using vitellogenin as a biomarker

This work evaluated the joint anti-estrogenic effects of pentachlorophenol (PCP) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) against 17beta-estradiol (E2) in juvenile goldfish (Carassius auratus) hepatocyte cultures. The level of vitellogenin (VTG) as a biomarker was determined by exposing hepatocytes to individual E2, PCP and TCDD, as well as to E2 in the presence of PCP, TCDD or their mixtures of various concentrations. PCP and TCDD did not exhibit estrogenicity. Both chemicals reduced the estrogenicity of E2, indicating the anti-estrogenic effects of PCP and TCDD. Their anti-estrogenic EC(50) values were calculated. The joint anti-estrogenic effects against E2 increased with increasing the PCP-to-TCDD ratio of mixture. Marking's indices were <0, suggesting an antagonism in anti-estrogenic effects between PCP and TCDD. The anti-estrogenic effects of PCP appeared to result primarily from the competitive binding to estrogen receptor. While TCDD may undergo an indirect binding process for its anti-estrogenic effects, the accurate mechanisms remain to be understood. The observed antagonism in anti-estrogenic effects resulted apparently from the mutual inhibition by PCP and TCDD.     

基于环境风险评价的危险品道路运输优化选线

张家港市拥有我国唯一的内河港保税区,区内化工产业密集,大量危险品在城市道路网上形成一个个“移动危险源”.本文系统分析了张家港市危险品道路运输过程中发生泄漏事故的风险:识别了道路网上危险品运输分布;提出了基于城市道路的泄漏事故率修正系数;运用ALOHA模型模拟事故情景、GIS计算影响区域长度和面积;从人口暴露和环境污染两方面构建风险评价模型并作为优化选线指标.基于上述基础,将风险评价模型应用于危险品道路运输网GIS平台,进行网络模块分析.结果表明,起迄点间路径的风险指数最小为14.12,该路径为最优路径,为张家港市危险品道路运输选线提供科学决策支持.     

Threat of heavy metal contamination in eight mangrove plants from the Futian mangrove forest,China

Mangrove plants play an important role in heavy metal maintenance in a mangrove ecosystem. To evaluate the characteristics of heavy metal contamination in the Futian mangrove forest, Shenzhen, China, eight heavy metals in mangrove sediments and plants were monitored, including essential elements such as Cu and Zn, and non-essential elements such as Cr, Ni, As, Cd, Pb and Hg. The results showed that the heavy metals exhibited the following scheme: Zn > As > Cu ≈ Cr > Pb > Ni > Cd ≈ Hg in sediment cores, among which Cd, As, Pb and Hg contents were nearly ten times higher than the background values. There was no significant difference in metal maintenance capability between native and exotic species. In mangrove plants’ leaves and stems, concentrations of Cu, Zn and As were higher than other heavy metals. The low bioconcentration factors for most heavy metals, except for Cr, implied the limited ability of heavy metal accumulation by the plants. Mangrove plants seem to develop some degree of tolerance to Cr. The factor analysis implies that anthropogenic influences have altered metal mobility and bioavailability.