选择性催化还原催化剂氧化脱除烟气中单质汞

以运用超声辅助浸渍法制备的V2O5-WO3/TiO2系列催化剂样品作为研究参考,在150 ～ 400℃,分别考察了某燃煤电厂新鲜的及已运行长达26 000 h的商用SCR脱硝催化剂对模拟烟气中单质汞(Hg0)的氧化性能,并利用SEM、BET、XRD等手段对样品的理化性质进行了表征.结果表明,电厂商用SCR催化剂对于燃煤烟气中的Hg0具有一定的催化氧化作用,但在250℃最佳反应温度时,最大汞氧化效率在50％以下,相同实验条件下,自制的1％V205-9％ WO3/TiO2(V1W9Ti)能够获得68.18％的最大汞氧化效率;通过考察NO、NH3、SO2和水蒸气对汞的氧化的影响发现,在低浓度NO以及5％02存在时,NO能够促进汞的氧化;SO2对汞的氧化有明显的抑制作用,而且其毒害作用具有一定的不可逆性;NH3在催化剂表面能够与Hg0发生竞争吸附,从而抑制了汞的氧化;水蒸气的存在容易导致催化剂的失活.此外,对催化剂氧化Hg0的机理进行了探讨.     

12种杀菌剂制剂对半闭弯尾姬蜂的急性毒性及安全性评价

采用试管药膜法测定了12种杀菌剂制剂对半闭弯尾姬蜂成蜂的急性接触毒性,结合安全性系数评价了供试药剂对半闭弯尾姬蜂的安全性。急性毒性测定结果表明,氟硅唑和啶菌噁唑对半闭弯尾姬蜂成蜂的接触毒性最高,LC50值分别为220.022和223.115 mg·L-1;其次为多抗霉素、丙森锌和戊唑醇,LC50值分别为436.496、472.358和638.638 mg·L-1;其余7种杀菌剂制剂嘧霉胺、啶酰菌胺、苯醚甲环唑、多菌灵、嘧菌酯、嘧菌环胺和异菌脲对半闭弯尾姬蜂成蜂的触杀毒性都较低,LC50值均大于1 000 mg·L-1。安全性评价结果表明,丙森锌和啶菌噁唑对半闭弯尾姬蜂成蜂具有高风险性,安全系数分别为0.16和0.42;嘧霉胺、多抗霉素、氟硅唑和戊唑醇为中等风险性,安全系数分别为1.43、1.56、2.20和3.23;其余6种杀菌剂制剂啶酰菌胺、苯醚甲环唑、多菌灵、嘧菌酯、嘧菌环胺和异菌脲对半闭弯尾姬蜂表现为低风险性,安全系数均大于5。结果显示:甾醇脱甲基抑制剂氟硅唑、戊唑醇和啶菌噁唑以及苯胺基嘧啶类杀菌剂嘧霉胺、有机硫杀菌剂丙森锌和抗菌素多抗霉素对半闭弯尾姬蜂成蜂具有急性毒性风险,在有害生物综合治理中应谨慎使用,特别是啶菌噁唑和丙森锌,以免对半闭弯尾姬蜂造成不良影响和危害。     

碳同位素在溢油鉴定中的应用研究

通过分析中国代表性原油、氯仿沥青"A"组分碳同位素和正构烷烃单体碳同位素组成,探讨其在溢油鉴定中的应用.结果表明,原油的碳同位素组成具有母质继承效应,不同来源的原油及其氯仿沥青"A"组分的碳同位素类型曲线形状不同,可以利用这种规律进行溢油鉴定.碳同位素的抗风化性是其用于油指纹鉴别的最大优点.正构烷烃单体碳同位素分析使得有机质碳同位素研究进入分子级水平,因其特征性和稳定性正日益成为重要且有效的油类污染物的"环境示踪剂".     

Study on the aerosol optical properties and their relationship with aerosol chemical compositions over three regional background stations in China

The special and temporal characteristics of aerosol optical depth (AOD) and Angstrom wavelength exponent (Alpha) and their relationship with aerosol chemical compositions were analyzed by using the data of CE318 sun-photometer and aerosol sampling instruments at Lin'an, Shangdianzi and Longfengshan regional atmospheric background stations. Having the highest AOD among the three stations, Lin'an shows two peaks in a year. The AOD at Shangdianzi station shows a single annual peak with an obvious seasonal variation. The AOD at Longfengshan station has obvious seasonal variation which peaks in spring. The Alpha analysis suggests that the aerosol sizes in Lin'an, Longfengshan and Shangdianzi change from fine to coarse categories. The relationship between the aerosol optical depths of the Lin'an and Longfengshan stations and their chemical compositions is not significant, which suggests that there is not a simple linear relationship between column aerosol optical depth and the near surface chemical compositions of atmospheric aerosols. The aerosol optical depth may be affected by the chemical composition, the particle size and the shape of aerosol as well as the water vapor in the atmosphere.     

基于响应面模型的区域大气污染控制辅助决策工具研发

基于CMAQ模型结果,利用高维克里金插值算法,建立了排放控制因子与污染物环境浓度的响应面模型(RSM),实现了大气污染可控源排放与复合污染水平的实时函数响应.研究结果显示,RSM对PM2.5的预测结果与CMAQ实际模拟结果的误差在容许范围内(最大误差小于0.20μg.m-3,3.89%).基于所建立的RSM,开发了RSM-VAT区域大气污染控制可视化辅助决策工具.使用RSM-VAT对美国8个典型城市的PM2.5污染状况进行了控制情景分析,通过"可视化展示"和"图表分析"二大模块,输出不同控制情景下的环境污染物浓度的实时响应图、可视化展示和数据分析图表等结果.     

Residential Preferences for River Network Improvement: An Exploration of Choice Experiments in Zhujiajiao,Shanghai, China

River networks have both ecological and social benefits for urban development. However, river networks have suffered extensive destruction as a result of urbanization and industrialization, especially in China. River restoration is a growth business but suffers poor efficiency due to a lack of social understanding. Assessing the benefits of river system restoration and recognizing public preferences are critical for effective river ecosystem restoration and sustainable river management. This study used a choice experiment with a multinomial logit model and a random parameter logit model to assess respondents’ cognitive preferences regarding attributes of river networks, and their possible sources of heterogeneity. Results showed that riverfront condition was the attribute most preferred by respondents, while stream morphology was the least preferred. Results also illustrated that the current status of each of three river network attributes was not desirable, and respondents would prefer a river network with a “branch pattern,” that is “limpid with no odor,” and “accessible with vegetation.” Estimated willingness to pay was mainly affected by household monthly income, residential location, and whether respondents had household members engaged in a water protection career. The assessment results can provide guidance and a reference for managers, sponsors, and researchers.     

空气微生物采样方法的比较

对3种空气微生物采样方法进行了比较。结果表明,在室外自然条件下,大气细菌粒子的沉降量与大气细菌粒子的浓度、大气真菌粒子的沉降量与大气真菌粒子的浓度均呈显著的正相关关系。对大气细菌粒子,用平皿沉降法分别与A·S采样器法、THK－201采样器法测定的结果相比,有非常显著的差异。平皿沉降法测定结果比后二者方法高出2.9倍和4.0倍;A·S采样器和THK－201采样器测定结果之间没有显著性差异。对大气真菌粒子,A·S采样器法和平皿沉降法与THK－201采样器法均有非常显著性差异;平皿沉降法与A·S采样器法测定结果之间没有显著性差异。进一步用直线回归分析的方法,得出了大气细菌粒子浓度与大气细菌粒子沉降量及大气真菌粒子浓度与大气真菌粒子沉降量之间的关系式。     

经济发达城市全面建成小康社会环境目标指标研究——以深圳市为例

从深圳新形势下率先全面建成更高水平的小康社会的发展和公众需求分析入手,分析当前全面建成小康社会的环境进程和构建全面小康环境目标指标体系的必要性.基于全过程、全覆盖、惠民性和衔接性考虑,提出应尊重深圳当前所处社会经济与环境阶段,遵守全过程防控思路,以人口、区域全覆盖和环境要素全面改善为工作核心,建立全社会行动体系,确立更严标准、更高质量的全面建成小康环境目标,构建包含源头防控、治污减排、质量提升、社会参与的全面建成小康社会环境指标体系.     

重金属污染土壤修复技术及其研究进展

土壤污染已经成为一个全球性的环境问题之一,而重金属污染在土壤污染中占有很大的比重,对人类生产和生活以及植物生长造成很大的威胁。本文从物化修复、化学修复、植物修复以及微生物修复等几个方面分别阐述了重金属污染土壤的修复技术及其研究进展。同时还介绍了复合污染中重金属的研究进展,指出了重金属复合污染土壤修复的研究方向。     

北京市2005年夏季大气颗粒物污染特征及影响因素

对2005年7～8月北京市不同功能区8个采样点PM10和PM2.5的浓度水平、空间分布、PM10/PM2.5比值进行了分析,并讨论了PM10和PM2.5的日变化特征及影响因素.结果表明,北京市夏季PM10和PM2.5日均浓度为155.37 μg/m3和87.70 μg/m3,分别为国家二级标准和美国PM2.5标准的1.04倍和1.35倍;PM2.5、PM10浓度在不同功能区存在一定差异;PM2.5和PM10的日变化以白天高,夜间低为主,且不同功能区的最高值对应于城市居民活动的不同高峰期;在湿度较高的情况下,PM2.5、PM10与湿度呈一定正相关性,且湿度对PM2.5的影响更大;降水前后PM2.5、PM10浓度变化情况表明降水的主要作用是清除粗粒子,对PM2.5的影响则较小.