A Multi‐Scale Analysis of Single‐Family Residential Water Use in the Phoenix Metropolitan Area

Studies that evaluate determinants of residential water demand typically use data from a single spatial scale. Although household‐scale data are preferred, especially when econometric models are used, researchers may be limited to aggregate data. There is little, if any, empirical analysis to assess whether spatial scale may lead to ecological fallacy problems in residential water use research. Using linear mixed‐effects models, we compare the results for the relationship of single‐family water use with its determinants using data from the household and census tract scales in the city of Phoenix. Model results between the household and census tract scale are similar suggesting the ecological fallacy may not be significant. Common significant determinants on these two spatial scales include household size, household income, house age, pool size, irrigable lot size, precipitation, and temperature. We also use city/town scale data from the Phoenix metropolitan area to parameterize the linear mixed‐effects model. The difference in the parameter estimates of those common variables compared to the first two scales indicates there is spatial heterogeneity in the relationship between single‐family water use and its determinants among cities and towns. The negative relationship between single‐family house density and residential water use suggests that residential water consumption could be reduced through coordination of land use planning and water demand management.     

环境中VOCs的污染现状及处理技术研究进展

综述了近十年来大气环境中挥发性有机物(VOcs)的污染现状及其主要处理技术的研究进展.介绍了目前大气环境中VOCs的主要处理技术(包括吸附、冷凝及膜分离等回收技术和燃烧、等离子体、光催化降解和生物降解等销毁技术)的适用条件、经济性、可操作性和净化效率.提出要对VOCs的吸收和生物降解的反应动力学模型、催化机制、材料的性能及微生物活性进行深入研究的建议.     

Ultrasonic preparation of nano-nickel/activated carbon composite using spent electroless nickel plating bath and application in degradation of 2,6-dichlorophenol

Ni was effectively recovered from spent electroless nickel （EN） plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine- formaldehyde-tetraoxalyl-ethylenediamine chelating resins were grafted on activated carbon （MFT/AG）. PdC12 sol was adsorbed on MFT/AC, which was then immersed in spent electroless nickel plating bath; then nano-nickel could be reduced by ascorbic acid to form a nano-nickel coating on the activated carbon composite （Ni/AC） in situ. The materials present were carefully examined by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and electro- chemistry techniques. The resins were well distributed on the inside and outside surfaces of activated carbon with a size of 120 ± 30 nm in MFT/AC, and a great deal of nano-nickel particles were evenly deposited with a size of 3.8 ± 1.1 nm in Ni/MFT. Moreover, Ni/AC was successfully used as a catalyst for ultrasonic degradation of 2.6-dichloronhenol.     

Mercury flows in large-scale gold production and implications for Hg pollution control

Large-scale gold production(LSGP) is one of the five convention-related atmospheric mercury(Hg) emission sources in the Minamata Convention on Mercury. However, field experiments on Hg flows of the whole process of LSGP are limited. To identify the atmospheric Hg emission points and understand Hg emission characteristics of LSGP, Hg flows in two gold smelters were studied. Overall atmospheric Hg emissions accounted for 10%–17% of total Hg outputs and the Hg emission factors for all processes were 7.6–9.6 kg/ton. There were three dominant atmospheric Hg emission points in the studied gold smelters, including the exhaust gas of the roasting process, exhaust gas from the environmental fog collection stack and exhaust gas from the converter of the refining process. Atmospheric Hg emissions from the roasting process only accounted for 16%–29% of total emissions and the rest were emitted from the refining process. The overall Hg speciation profile(gaseous elemental Hg/gaseous oxidized Hg/particulate-bound Hg) for LSGP was 34.1/57.1/8.8. The dominant Hg output byproducts included waste acid, sulfuric acid and cyanide leaching residue. Total Hg outputs from these three byproducts were 80% in smelter A and 84% in smelter B. Our study indicated that previous atmospheric Hg emissions from large-scale gold production might have been overestimated.Hg emission control in LSGP is not especially urgent in China compared to other significant emission sources(e.g., cement plants). Instead, LSGP is a potential Hg release source due to the high Hg output proportions to acid and sludge.     

层状云清除气溶胶的数值模拟

建立了一个一维层状云系的气溶胶清除模式,模式旨在模拟云发展过程中云、雨水中气溶胶浓度的时空演变规律,研究气溶胶粒子的云内清除和云下清除的相对贡献大小及其湿沉降速率等.模拟结果在一定程度上与实测结果相符.     

铅锌冶炼弃渣有害特征及其浸出行为研究

铅锌弃渣是有色金属工业排出的大宗固体废物之一。其中有铅冶炼系统排铅烟花炉渣,锌系统排锌回转窑渣。铅锌弃渣一般含有多种超过排放标准而目前又尚无成熟工艺提取的有价值和稀贵金属元素。这些废渣的堆存直接影响自然景观,并有可能对环境如土壤、水体和作物等造成危害。因此,考察铅锌渣的有害特征,研究其水浸出行为与规律,对解决铅锌弃渣对环境污染,寻求同行业固体废物的治理途径具有重要的现实意义。     

SO2和O3动态胁迫烟草致病的暴露试验

ＳＯ_２和Ｏ_３动态胁迫烟草致病的暴露试验陈锦云，兰志斌，苏珍山，曾军，王阳青（福建龙岩地区烟科所龙岩３６４０００）关键词Ｓ）_２和Ｏ_３；烟草；气候斑点病，动态胁迫暴露ＴＨＥＤＹＮＡＭＩＣＳＴＲＥＳＳＥＸＰＯＳＵＲＥＴＥＳＴＯＮＴＯＢＡＣＣＯＢＬＡＤＥ...     

广州夏季办公室内细颗粒中多环芳烃污染特征研究

大部分的都市办公人群每天在办公室至少度过8 h。而室外环境的渗透、办公室内吸烟、办公设备使用和中央通风系统均可能导致细颗粒物及多环芳烃(PAHs)在室内积聚而造成微环境污染。2015年5—6月,在广州市3种不同功能区(商住区、高新产业区、工业区)共选取了14间不同类型的办公室,对其室内外PM_(2.5)和多环芳烃进行同步监测。结果表明,(1)14间中有12间办公室内的PM_(2.5)浓度水平高于世界卫生组织(WHO)的推荐值25μg·m-3;(2)与国内外类似研究相比,办公室内外∑16PAHs及Ba P-eq的监测浓度水平均较低,并呈现一致规律:文印>室外>吸烟>多人>单人>无窗(无人),其中Ba P-eq低于欧盟规定的安全限值1 ng·m-3;(3)文印工作和吸烟行为与室内PM_(2.5)和PAHs浓度升高有密切关系,分别对5环和4环PAHs贡献明显;(4)其他无明显内源的办公室的细颗粒中PAHs污染在监测期间主要来源于室外贡献。     

基于人均生态承载力的安徽省资源环境公平性研究

通过对人均生态承载力内涵的扩展,提出了生态承载系数的概念。从多个时间断面出发,计算2001—2010年安徽省17个地市的人均生态承载力,并选取能源消耗、水资源消耗、SO2排放和COD排放4个评价因子,构建基于人均生态承载力的安徽省资源环境基尼系数和生态承载系数的计算与评价方法。结果表明:(1)安徽省SO2排放的资源环境基尼系数高于0.4的警戒线,能源消耗的资源环境基尼系数接近0.4的警戒线,水资源消耗和COD排放的资源环境基尼系数均处于相对平均等级。(2)总体来看,省内资源型城市马鞍山、淮南,经济较发达城市合肥和沿江工业城市安庆、芜湖是安徽省资源消耗和污染物排放不公平性的主要因子,需要优化资源环境分配;皖南山区城市黄山、池州和宣城是安徽省资源消耗和污染物排放公平性的主要因子。该研究可为安徽省资源环境安全性评估和分配提供理论依据。     

地表水中微量氯代芳烃和硝基取代芳烃化合物的分析方法

建立了固相萃取、毛细管气相色谱-电子捕获检测、内标标准曲线法定量分析地表水中十三种氯苯、硝基氯苯和硝基苯类化合物的方法.该法对这些化合物的平均回收率在62%-101%之间,变异系数在3%-27%之间,方法最小检测浓度在0.01-1.31μg·1-1之间.应用本方法对太湖水中的氯代芳烃和硝基取代芳烃化合物进行了三次采样分析,定量重现性较好.