吸附剂烟气脱砷的研究现状

大气砷污染问题日益引起人们的重视,吸附剂能够在去除烟气中砷的同时去除其他有害气体,是控制烟气砷含量、防止砷污染的有效途径.文章分析了砷在废气中的形态及分布,总结了近年来氧化钙、活性炭、飞灰和金属氧化物作为吸附剂用于烟气脱砷的最新研究进展,重点分析了各自的吸附机理及不同因素对脱砷过程的影响.指出吸附过程通常以化学吸附为主...     

偶氮染料分子结构对其生物脱色影响的研究进展

偶氮染料是工业中染料用量最大的一类,不同的分子结构对其微生物脱色性能具有一定的影响作用。文章综述了偶氮染料分子结构中的取代基种类及其取代位置对染料的脱色规律,以及分子特征结构对微生物脱色的量化分析。对目前染料生物脱色规律研究中存在的问题进行了分析,提出相应的对策措施。     

彭水电站蓄水前后鱼类群落多样性特征

根据2006-2008年9-10月渔业资源动态监测资料,分析研究了彭水电站蓄水前后坝上和坝下江段鱼类群落结构变化及其生物多样性变化特征.研究结果表明:3次监测中,调查江段出现的鱼类共有9科44属63种,其中长江上游特有鱼类22种;渔获物中,群体数量主要由体重＜50 g的小型鱼类和幼鱼组成,而群体重量主要由＜500g的中...     

动力与热力抬升对烟气抬升高度的影响分析

通过模式选择和计算,得出烟气抬升高度的增加与动能和热能的关系,表明当烟囱出口处风速分别为3 m/s、2 m/s和1 m/s时欲增加同样大小的烟气抬升高度,需要的动能比热能要高,结论认为烟气的热力提升比动力提升的贡献大。     

基于生态系统的水环境压力分区指标体系构建

为了科学合理的完成水环境压力分区,构建水环境压力分区指标体系是其关键和基础.鉴于水环境压力涉及因素的系统性.相互联系性,从生态系统的角度考虑选取水环境压力分区指标十分必要;由于水环境压力涉及方面的相互联系性,其表征指标之间往往存在信息量的重叠,为了避免信息的重复表达,减少不必要的工作量,同时避免冗余指标带来的干扰,需对...     

含油废水处理技术

概述了含油废水的来源、特点、分类及危害,介绍了含油废水的处理方法的原理、优势及存在的问题,同时简述了各种处理方法的最新研究成果,最后提出了含油废水发展趋势。     

Primary neuronal-astrocytic co-culture platform for neurotoxicity assessment of di-(2-ethylhexyl) phthalate

Plastics such as polyvinyl chlorides （PVC） are widely used in many indoor constructed environments; however, their unbound chemicals, such as di-（2-ethylhexyl） phthalates （DEHP）, can leach into the surrounding environment. This study focused on DEHP＇s effect on the central nervous system by determining the precise DEHP content in mice brain tissue after exposure to the chemical, to evaluate the specific exposure range. Primary neuronal-astrocyte co-culture systems were used as in vitro models for chemical hazard identification of DEHP. Oxidative stress was hypothesized as a probable mechanism involved, and therefore the total reactive oxygen species （ROS） concentration was determined as a biomarker of oxidative stress. In addition, NeuriteTracer, a neurite tracing plugin with ImageJ, was used to develop an assay for neurotoxicity to provide quantitative measurements of neurological parameters, such as neuronal number, neuron count and neurite length, all of which could indicate neurotoxic effects. The results showed that with 1 nmol/L DEHP exposure, there was a significant increase in ROS concentrations, indicating that the neuronal-astrocyte cultures were injured due to exposure to DEHP. In response, astrocyte proliferation （gliosis） was initiated, serving as a mechanism to maintain a homeostatic environment for neurons and protect neurons from toxic chemicals. There is a need to assess the cumulative effects of DEHP in animals to evaluate the possible uotake and effects on the human neuronal system from exoosure to DEHP in the indoor environment.     

Characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China

To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate(TSP) and PM10samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were(183 ± 73),(201 ± 84) and(190 ± 66) μg/m3respectively, and the average PM10 were(171 ± 82),(178 ± 65) and(179 ± 55) μg/m3respectively. The lowest TSP and PM10concentrations occurred at the background Shaping site of Changsha. The average ratio of ρ(PM10)/ρ(TSP) was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8–56.5, 18.1–76.3, 3.9–26.1 and 148.0–460.9 ng/m3, respectively, while in PM10samples, were 16.4–42.1, 15.5–67.9, 3.3–22.2 and 127.9–389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest.     

Characterization of extracellular polymeric substances in the biofilms of typical bacteria by the sulfur K-edge XANES spectroscopy

A combined approach of physicochemical extraction and sulfur K-edge X-ray absorption near-edge structure（XANES） spectroscopy was applied to characterize the extracellular polymeric substances（EPS） of typical bacterial biofilms in this study. Physicochemical analysis showed variation of the contents of DNA,polysaccharide and protein in different fractions of EPS in different mediums. The sulfur K-edge XANES analysis yielded a variety of spectra.Spectral fitting of the XANES spectra utilizing a large set of model compounds showed that there was more reduced sulfur in both LB-EPS（loosely bound EPS） and TB-EPS（tightly bound EPS） of all the biofilms in LB medium than in R2 A medium. More oxidized sulfur was identified in LB-EPS than that in TB-EPS,suggesting different niches and physiological heterogeneity in the biofilms. Our results suggested that the sulfur K-edge XANES can be a useful tool to analyze the sulfur speciation in EPS of biofilms.     

西安市2013年空气质量状况分析

本文收集西安市2013年环境监测站发布的空气质量指数（AQI）及环境空气状况与监测月报资料,对空气质量等级、AQI变化情况、主要污染物浓度变化趋势及采暖期和非采暖期浓度比较进行分析.研究结果表明：西安市2013空气质量二级以上的达标率为37.8％,年均AQI值为151,SO2、NO2、PM10和PM2.5的月监测浓度变化趋势无显著意义,采暖期平均浓度均显著高于非采暖期平均浓度,PM2.5采暖期均值是非采暖期均值的3.09倍.由此可见控制SO2、NO2、PM10和PM2.5的排放是改善西安市空气质量的重点工作.