Bacterial resistance to lead: Chemical basis and environmental relevance

Natural bacterial isolates from heavily contaminated sites may evolve diverse tolerance strategies, including biosorption, efflux mechanism, and intracellular precipitation under the continually increased stress of toxic lead (Pb) from anthropogenic activities. These strategies utilize a large variety of functional groups in biological macromolecules (e.g., exopolysaccharides (EPSs) and metalloproteins) and inorganic ligands, including carboxyl, phosphate and amide groups, for capturing Pb. The amount and type of binding sites carried by biologically originated materials essentially determines their performance and potential for Pb removal and remediation. Many factors, e.g., metal ion radius, electronegativity, the shape of the cell surface sheath, temperature and pH, are thought to exert significant influences on the abovementioned interactions with Pb. Conclusively, understanding the chemical basis of Pb-binding in these bacteria can allow for the development of effective microbial Pb remediation technologies and further elucidation of Pb cycling in the environment.     

Optimization analysis of silver extraction from waste monolithic ceramic capacitor using persulfate-ammonia system

Journal of Material Cycles and Waste Management - Monolithic ceramic capacitors (MLCCs) contain a high level of silver. This paper describes a method to recover silver from the waste MLCCs. First,...     

全球和中国变暖特征及未来趋势

自小冰期在上世纪末结束以来，全球气温波动上升，至本世纪８０年代全球平均上升了０．４５±０．１５℃。２０～３０年代的强烈升温（＞０．３℃）归因于自然回暖，６０年代至７０年代初出现北半球为主的一度降温，８０年代又强烈升温至今未息，这次升温以冬季和夜间变暖为主，高纬度地区又大于中低纬度地区，可认为是人为的ＣＯ２等温室气体增加起了重要作用。中国２０～３０年代升温，６０年代降温和８０年代北部地区升温均大于全球平均值。全球降水变化远比温度变化复杂，总趋势略有上升，中国基本处在中纬度降水减少带中，呈现暖干化趋势。在２０年代和６０年代有两次变旱的气候跃变，相伴着旱灾的加重，但降水变率很大，洪涝灾害更为严重。未来气候主要取决于ＣＯ２及其它微量气体增加所加犟的温度效应，全球继续并持久变暖。根据政府间气候变化委员会（ＩＰＣＣ）预测的下世纪温室气体排放，Ｈｕｌｍｅ等（１９９２）综合新近若干模式研究结果，预期全球平均升温最佳估计值到２０５０年为１．２℃（低限与高限范围为０．８℃和１．８℃），而到２１００年为２．５℃（变化范围１．６～３．８℃），中国到２０５０年升温值在东部和东南部为１．０～１．５℃，在东北、华北和西部为１．５～２     

Emission Inventories of Carbon-containing Greenhouse Gases in and Technological Measures for Their Abatement

The report summarizes surveys on carbon inventories and initiatives on sustainable carbon cycling taken by the Research Center for EcoEnvironmental Sciences, where the authors work/worked. The first part of the report, which appeared in the preceding issue of this journal, deals with the concept of sustainable carbon cycling, the historic evolution of carbon cycling processes in China, carbon pool enhancement, value addition,carbon sequestration and carbon balance. This very paper, as the second part of the report, covers the results of carbon dynamics modeling, emission inventories of various carbon-containing greenhouse gases and their potential abatement measures.     

基于灰色模型GM(1,1)的河南省能源消费预测

本文选取河南省2004-2012年能源消费量作为样本数据,建立了基于灰色模型GM(1,1)的河南省能源消费量预测模型,并预测了河南省2013-2020年能源消费量,2020年预测值41071万吨标煤,比2012年增加73.68%。结合河南省能源消费结构现状,提出了河南省能源消费总量控制及能源结构调整的对策与建议。     

饮用水中消毒副产物1,1-二氯丙酮的形成机制

采用气相色谱/质谱法,以甲基叔丁基醚为萃取剂,1,2-二溴丙烷为内标物,建立了消毒副产物1,1-二氯丙酮(DCAce)的测定方法.以L-亮氨酸为前体物,考察了DCAce的形成过程和影响因素.结果表明,当氯胺投加量在5~30 mg·L-1范围内,DCAce的生成量随着氯胺投加量的增加而增加;DCAce的生成量随着p H的增大而逐渐减小,在酸性条件下DCAce的生成量比中性和碱性条件下高;在15~35℃范围内,温度对DCAce生成量的影响较明显,生成量随着温度的升高而增加;L-亮氨酸形成DCAce的过程包括8个步骤,经过取代、氧化、断键、氨基重氮化和还原等一系列复杂的反应后,最终形成DCAce.     

上海市城乡梯度上土壤重金属空间分布及其影响因素定量分析

提出了两种上海市城乡梯度上土壤重金属空间格局及影响因素的研究方法:缓冲区分析方法和滑动窗口分析方法.缓冲区分析的结果表明,人口变化指数及2~3 km范围内的建设用地比例能显著影响Cd和Cu的空间分布(p0.05),而3 km范围内的道路密度显著影响Pb的浓度.滑动窗口分析的结果表明,Cd和Cu主要受工业活动的影响,而Pb受交通流量,以及反映城市景观扩张过程的景观形状指数的影响.相关分析表明,两种方式揭示了较为相似的土壤重金属空间累积影响因素,即工业活动相关的城市化过程.研究对理解城市化的发生机制及其重金属环境风险的管理有重要意义.     

Short-term effects of real-time individual fine particulate matter exposure on lung function: a panel study in Zhuhai,China

Environmental Science and Pollution Research - Fine particulate matter (PM2.5) is still the primary air pollutant in most Chinese cities and its adverse effects on lung function have been widely...     

Dynamics of phosphorus fractions and potential bioavailability along soil profiles from seasonal-flooding wetlands in a Chinese estuary

Environmental Science and Pollution Research - Soil phosphorus fractions in wetland ecosystems have received increasing attention due to its high eutrophication risks. Soil samples were collected...