同步辐射XRF和XANES研究重金属污染环境中小羽藓体内硫元素的生物指示作用

在实验室将小羽藓(Haplocladium)暴露于不同浓度的铅、铁、铬重金属环境下进行培育,分别应用同步辐射X射线荧光(SRXRF)方法测定小羽藓植株硫元素的含量和X射线吸收近边结构(XANES)分析不同价态的硫所占的相对含量.结果表明,暴露于铅、铁下的小羽藓植株内硫的含量明显增加,铅、铁浓度分别为400 mg/L和200 mg/L时,硫元素含量下降.培养周期为15 d时,小羽藓在100 mg/L铅胁迫下,低价硫由对照组的17.8%升高到23.6%,而同时以硫酸盐形式存在的硫由对照组的56.3%下降到51.2%.在400 mg/L铅胁迫时,低价硫含量增加到24.8%,硫酸盐中的硫所占的比例下降到48.4%.小羽藓植株内的胱氨酸、半胱氨酸、甲硫氨酸和谷胱甘肽中所含低价态硫的总相对含量增加,以硫酸盐态存在的硫相对含量明显下降.研究表明,重金属污染环境导致小羽藓硫吸收同化过程中硫元素含量和价态变化特征具有一定的生物指示作用.     

废印刷电路板资源化处理技术研究进展

随着电子技术的不断发展和科技进步,电子产品更新换代速度的加快,随之产生的电子废弃物数量急剧增加。废印刷电路板作为一种电子废弃物含有一些有害的金属元素,它的随意丢弃将会对自然环境和人体健康构成威胁,因此,废印刷电路板的处理与处置成为亟待解决的问题。文章分析了废印刷电路板资源化处理的意义,介绍了国内外常用的几种处理技术,如冶金技术、机械处理技术、焚烧技术等,对目前尚未应用但很有发展前景的热解与微波处理技术也作了介绍,并对这些方法作了简要的分析与评述。     

大气污染总量控制GA方法中的多源模拟系统

大气污染总量控制的GA方法,是利用遗传算法(GA)的自适应全局搜索寻优功能,通过模拟的自然进化机制来求算经过全局优化的区域允许排放总量以及区域允许排放总量在区域内各污染源之间的分配方案的一种新的大气污染总量控制方法。在基于遗传算法的大气污染总量控制中,需要运用一个高效而可靠的大气污染多源模拟系统,以便根据源强分布快速计算出准确的浓度场。文章介绍了该大气污染多源模拟系统的设计与实现技术。     

太阳能技术在住宅建筑中的应用

太阳能技术的应用对我国住宅产业的发展具有重要意义。文章分析了目前国际和国内住宅建设领域中太阳能技术的应用形式与局限,指出了我国实现太阳能住宅建筑一体化进程中应着重解决的主要问题。     

悬浮液进样-AAS法测定TSP中锌、铅和铁的含量

用浓硝酸和高氯酸混酸体系在超声波作用下消解滤膜,加入稳定剂琼脂,用超声波震荡15min制成悬浮液,用火焰原子吸收光谱法测定TSP中的锌、铅和铁的含量,并以传统浓HNO3-H2O2湿法消解-原子吸收光谱法的测定结果为参考对测定值进行t检验,结果表明:RSD≤3.27%(n=6),两种方法的相对误差<±0.85%,且两种方法无显著性差异,说明悬浮液进样法的测定结果准确、可靠。     

丹江口水库总氮监测与综合分析

在优级化布点基础上对丹江口水库汉江子库总氮浓度进行监测与综合分析。近几年丹江口水库总氮浓度稳定,进一步下降趋势不明显,2008年全库区总氮浓度仍超过GB3838-2002Ⅲ类标准限值,在湖北省地表水环境监测网水库中相对较高。其中,丰水期最高,平水期最低,库尾最高,面积较大的库湾最低。来自河流的外源污染是汉库总氮超标主要原因,与上游水土流失、农业面源污染、工业和城镇生活污染有关。建议进一步加强库内和集水区综合污染防治,加强包括该库底质在内的环境监测。     

Evaluation of ambient air quality in Guangzhou, China

On the basis of the reported air quality index （API） and air pollutant monitoring data provided by the Guangzhou Environment Monitoring Stations over the last twenty-five years, the characteristics of air quality, prominent pollutants, and variation of the average annual concentrations of SOE, NOE, total suspended particulate （TSP）, fine particulates （PM10）, CO and dustfall in Guangzhou City were analyzed. Results showed that TSP was the prominent pollutant in the ambient air environment of Guangzhou City. Of the prominent pollutants, TSP accounted for nearly 62%, SOE 12.3%, and NOx 6.4%, respectively. The average API of Guangzhou over 6 years was higher than that of Beijing, Tianjin, Nanjing, Hangzhou, Suzhou and Shanghai, and lower than that of Shenzhen, Zhuhai and Shantou. Concentrations of air pollutants have shown a downward trend in recent years, but they are generally worse than ambient air quality standards for USA, Hong Kong and EU. SOE and NOx pollution were still serious, impling that waste gas pollution from all kinds of vehicles had become a significant problem for environmental protection in Guangzhou. The possible causes of worsening air quality were also discussed in this paper.     

Pollutant loads of surface runo inWuhan City Zoo, an urban tourist area

The pollutant loads of surface runoff in an urban tourist area have been investigated for two years in the Wuhan City Zoo, China. Eight sampling sites, including two woodlands, three animal yards, two roofs and one road, were selected for sampling and study. The results indicate that pollutants ranked in a predictable order of decreasing load （e.g. animal yard〉roof〉woodland〉road）, with animal yards acting as the key pollution source in the zoo. Pollutants were transported mainly by particulate form in runoff. Particulate nitrogen and particulate phosphorous accounted on average for 61%, 78% of total pollutant, respectively, over 13 monitored rainfall events. These results indicate the treatment practices should be implemented to improve particulate nutrient removal. Analysis of the M（V） curve indicate that no first flush effect existed in the surface runoff from pervious areas （e.g. woodland, animal ground yard）, whereas a first flush effect was evident in runoff from impervious surfaces （e.g. animal cement yard, roof, road）.     

事故后果模拟分析法在安全评价应用中的问题及处理

分析了事故后果模拟分析方法在安全评价应用中存在的问题,方法中有关参数要根据现场实际情况计算、测量选取,否则计算结果就会失真.     

A forest pathogen drives change in plant functional trait composition in the Southwest Australian Floristic Region

Plant functional traits weighted by cover-abundance have been used to measure change across a wide range of temperature, moisture and grazing gradients. We use this approach along a chronosequence of disease infestation (Phytophthora cinnamomi) in the species-diverse Banksia woodlands of the Southwest Australian Floristic Region (SWAFR). We compare the use of absolute (community-weighted totals-CWT) and relative cover data (community-weighted means-CWM) to demonstrate the importance of total cover change in reference to the Mass Ratio Hypothesis.Plant species cover-abundance was recorded along a space-for-time disease chronosequence, and functional trait data collected for the 48 dominant species from healthy vegetation. Six traits with deduced links to key ecosystem functions were measured for each species and values for two indices (CWT and CWM) compared along the disease chronosequence. Trait data was collected on plant height, growth form, specific leaf area, leaf dry matter content, root pattern and carbohydrate storage.Despite substantial shifts in individual species cover and a reduction in total species cover, the majority of CWM values did not change significantly following disease infestation. The use of relative cover-abundance data disregards important changes in total species cover, apparent from our comparative analysis. In contrast to CWMs, all CWT values were reduced following disease infestation, suggesting a potential reduction in productivity, reduced capacity as a carbon sink and altered site water balance. Verification of these potential changes in ecosystem functions is required using fine-scale quantitative techniques. The CWT index is complementary to traditional CWMs and useful when analysing changes in plant trait data where total species cover changes have been detected. In relation to P. cinnamomi infestation, shifts in CWT trait values indicate the ability of an introduced plant pathogen to have substantial indirect impacts beyond substantial floristic change.