某厂周围居民汞污染健康风险评估研究

调查某厂环境汞污染致周围居民健康风险.通过对某厂周围环境介质及食物中汞含量进行测定,采用有阈化学物质健康风险评价模型,对周围2 km范围内居民健康风险进行评价.结果表明:某厂周围居民经呼吸道、消化道、皮肤汞的日均暴露量分别为0.5×10-4 mg/(kg·d)、9.35×10-5 mg/(kg·d)及2.04×10-6 mg/(kg·d),汞污染致当地居民健康风险处于可接受风险水平.某厂周围环境介质已受到一定程度的污染,但尚未影响到居民健康,由于汞的累积效应,某厂周围汞污染仍需引起关注.     

三峡库区农村填埋垃圾渗滤液污染物含量评价

为了研究农村填埋垃圾渗滤液污染物含量和组成,选取了三峡库区10个垃圾填埋场渗滤液作为研究对象,对其无机阴离子、重金属含量及组成成分和pH值进行了分析.结果发现,垃圾填埋场渗滤液p H值均呈碱性,同时,SO_4~(2-)浓度均普遍高于Cl~-浓度.此外,受氧化还原电位和p H值的影响,呈现出NO_3~--N浓度NO_2~--N浓度的分布趋势.通过指数和单因子评价法对填埋垃圾的重金属含量进行了分析和评价.结果表明,Cr无污染现象,但Cd污染现象普遍十分严重,Pb、Zn和Cu污染则在不同的地点呈现出空间差异性.研究表明,三峡库区农村填埋垃圾特异性高,污染物来源构成差异性大.     

陶瓷膜技术过滤0＃柴油废水的试验

在胶束技术基础上,结合一种由简单金属盐和NaOH通过错流过滤方式形成的氢氧化物动态陶瓷膜,对0＃柴油废水进行去除试验.结果表明,在1g/L MgCl2和1g/L FeCl3分别作为成膜盐的试验中MgCl2处理效果更佳.在表面活性剂十二烷基苯磺酸钠(SDBS)处于临界胶束浓度1.2 mmol/L条件时,当MgCl2溶液质...     

Chemical speciation and partitioning of trace metals (Cd, Co, Cu, Ni, Pb) in the lower Athabasca river and its tributaries (Alberta, Canada)

Concentrations of Cd, Co, Cu, Ni and Pb were measured in particulate and dissolved phases at 11 sites located upstream and near Athabasca oil sands development. The in situ discrimination between non-labile and labile dissolved metals was done using diffusive gradients in thin-films (DGT) devices. The DGT-labile fraction of Co and Ni was 30% lower near development sites whereas Cu, Cd and Pb showed minor changes spatially. It was found that an 8-fold increase in dissolved organic matter (DOM) near development induced a rapid decrease in DGT-labile metals. Dissolved metal concentrations were used along with DOM, major ions, nutrients, pH and conductivity to calculate the distribution of dissolved metal species using the speciation model WHAM. Labile-DGT metal concentrations agreed well with WHAM-predicted concentrations. It was also found that a significant amount of metals were associated with the non-DGT labile fraction (i.e. colloidal DOM) and colloid abundance was more important than suspended particulate matter abundance in influencing metal mobility near Athabasca oil soils development. Since changes in colloidal DOM levels are likely to be the result of surface mining activities, this confirms the serious effects of oil sands activities on metal biogeochemical cycles in the lower Athabasca River.     

农村灾害避难场所布局规划评价研究——以四川省小鱼洞镇为例

灾害避难场所不仅在灾中或灾后能为农村灾民提供一个临时安置或生存场所,而且更是农村整合其有限资源开展防灾减灾工作的平台,在农村社区减灾中工作发挥着重要的作用,然而相关研究工作较少。以四川省彭州市小鱼洞镇为例,通过对政府既定的避难场所进行安全性、通达性、收容性、生活性等分析,综合评价这些避难场所的布局合理性。以期为该区避难所的进一步建设提供科学依据,也为农村灾害避难所的规划和评价提供参考实例。     

烟囱直径对除尘系统的影响

分析了风机全压在除尘系统中的分配,以及烟囱直径对管网出口动压损失的影响,得出适当加大烟囱出口管径,降低管网出口气体的速度,可降低系统能耗,为风机烟囱设计和选型提供了参考。     

Inactivation, reactivation and regrowth of indigenous bacteria in reclaimed water after chlorine disinfection of a municipal wastewater treatment plant

Disinfection of reclaimed water prior to reuse is important to prevent the transmission of pathogens. Chlorine is a widely utilized disinfectant and as such is a leading contender for disinfection of reclaimed water. To understand the risks of chlorination resulting from the potential selection of pathogenic bacteria, the inactivation, reactivation and regrowth rates of indigenous bacteria were investigated in reclaimed water after chlorine disinfection. Inactivation of total coliforms, Enterococcus and Salmonella showed linear correlations, with constants of 0.1384, 0.1624 and 0.057 L/(mg·min) and R² of 0.7617, 0.8316 and 0.845, respectively. However, inactivation of total viable cells by measurement of metabolic activity typically showed a linear correlation at lower chlorine dose (0-22 (mg·min)/L), and a trailing region with chlorine dose increasing from 22 to 69 (mg·min)/L. Reactivation and regrowth of bacteria were most likely to occur after exposure to lower chlorine doses, and extents of reactivation decreased gradually with increasing chlorine dose. In contrast to total coliforms and Enterococcus, Salmonella had a high level of regrowth and reactivation, and still had 2% regrowth even after chlorination of 69 (mg·min)/L and 24 hr storage. The bacterial compositions were also significantly altered by chlorination and storage of reclaimed water, and the ratio of Salmonella was significantly increased from 0.001% to 0.045% after chlorination of 69 (mg·min)/L and 24 hr storage. These trends indicated that chlorination contributes to the selection of chlorine-resistant pathogenic bacteria, and regrowth of pathogenic bacteria after chlorination in reclaimed water with a long retention time could threaten public health security during wastewater reuse.     

Trichloroethylene degradation by PVA-coated calcium peroxide nanoparticles in Fe(II)-based catalytic systems: enhanced performance by citric acid and nanoscale iron sulfide

Environmental Science and Pollution Research - In this study, the enhanced trichloroethylene (TCE) degradation performance was investigated by polyvinyl alcohol coated calcium peroxide...     

基于提升职工安全素质的巡检“三化”管理模式应用

基于化工罐区巡检工作现状,围绕提升职工安全素质,提出了从"制度化、细节化、可视化"3个方面构建罐区巡检"三化"管理模式,并给出了具体做法,以实现将化工原辅料储运的安全风险防范关口前移,有效提升化工类罐区运行的本质安全。     

"水俣病事件"50周年祭

（1956-2006） 100年前,日本氮肥公司（1906年创业时称曾木电气,1908年经重组始称日本氮肥株式会社）水俣工厂的开工,彻底改变了水俣,这个位于不知火海边的小渔村的命运.工厂的开工,带来就业,繁荣了当地经济,随着氨肥产量的不断增加,小渔村发展成为一个域市.