Field Survey of Trans-boundary Air Pollution with High Time Resolution at Coastal Sites on the Sea of Japan during Winter in Japan}

An intensive field survey, with 6-h measurement intervals, of concentrations of chemical species in particulate matter and gaseous compounds was carried out at coastal sites on the Sea of Japan during winter. The concentration variation of SO₂(g) and HNO₃(g) were well correlated, whereas the NH₃(g) concentration variation had no correlation with those of SO₂(g) and HNO₃(g). The NH₄ ⁺ (p)/non-sea-salt- (nss-)SO₄ ^{2 −}(p) ratio in particulate matter was mainly affected by the location of the sampling site. One or more concentration peaks of nss-Ca^{2 +} for survey period were observed. Backward trajectories analyses for the highest nss-Ca^{2 +} concentration peaks showed some inconsistency in pathways. We consider that insufficient mixing of the atmosphere and/or insufficient time for the transported air pollutants to react with those discharged locally are the most likely explanations for the discrepancies between the measured products [HNO₃][NH₃] and the calculated values.     

Dynamic changes in microbial activity and community structure during biodegradation of petroleum compounds： A laboratory experiment

With 110-d incubation experiment in laboratory,the responses of microbial quantity,soil enzymatic activity,and bacterial community structure to different amounts of diesel fuel amendments were studied to reveal whether certain biological and biochemical characteristics could serve as reliable indicators of petroleum hydrocarbon contamination in meadow-brown soil,and use these indicators to evaluate the actual ecological impacts of 50-year petroleum-refining wastewater irrigation on soil function in Sbenfu irrigation area.Results showed that amendments of≤1000 mg/kg diesel fuel stimulated the growth of aerobic beterotrophic bacteria,and increased the activity of soil dehydrogenase,hydrogenperoxidase,polypbenol oxidase and substrate-induced respiration.Soil bacterial diversity decreased slightly during the first 15 d of incubation and recovered to the control level on day 30.The significant decrease of the colony forming units of soil actinomyces and filamentous fungi can be taken as the sensitive biological indicators of petroleum contamination when soil was amended with≥5000 mg/kg diesel fuel.The sharp decrease in urease activity was recommended as the most sensitive biochemical indicator of heavy diesel fuel contamination.The shifts in community structure to a community documented by Sphingomonadaceae withinα-subgroup of Proteobacteria could be served as a sensitive and precise indicator of diesel fuel contamination.Based on the results described in this paper,the soil function in Shenfu irrigation area was disturbed to some extent.     

天山典型冰川区雪冰中碳质气溶胶浓度特征研究

根据2002年与2004年在天山乌鲁木齐河源1号冰川与奎屯河哈希勒根51号冰川采集的粒雪与冰川冰样品,利用热/光反射法(TOR)分析得到有机碳(OC)与元素碳(EC)的浓度,并探讨了天山典型冰川区雪冰中碳质气溶胶浓度的时空特征与环境意义.结果表明,总碳(TC)浓度从高到低依次为:乌鲁木齐河源1号冰川西支雪坑(1 943 ng.g-1)>乌鲁木齐河源1号冰川东支雪坑(989 ng.g-1)>奎屯河哈希勒根51号冰川雪坑(150 ng.g-1)>乌鲁木齐河源1号冰川东支冰川冰(77 ng.g-1),OC和EC的浓度序列也较为类似;天山冰川区雪层中OC浓度平均值为557 ng.g-1,EC浓度平均值为188 ng.g-1.不同冰川积累区雪层剖面的中下部污化层附近一般都会出现碳质气溶胶浓度峰值,但某些突发性事件会使得表层雪也产生浓度峰值;在季节性碳排放(如居民采暖、农业活动等)与碳传输(如大气环流等)的影响下,雪层中碳质气溶胶浓度在7～11月间总体呈波动下降的趋势;冰川冰与粒雪间碳质气溶胶浓度可能存在着数量级的差异,这主要受到冰川所在环境、雪冰采样时空条件等因素影响;雪层表面是否存在EC对反照率有很大影响,模拟显示在波长为300～700 nm范围内反照率平均降低0.22.     

Bacterial reduction and release of adsorbed arsenate on Fe(Ⅲ)-, Al- and coprecipitated Fe(Ⅲ)/Al-hydroxides

Mobilization of arsenic under anaerobic conditions is of great concern in arsenic contaminated soils and sediments. Bacterial reduction of As(V) and Fe(Ⅲ) influences the cycling and partitioning of arsenic between solid and aqueous phase. We investigated the impact of bacterially mediated reductions of Fe(Ⅲ)/Al hydroxides-bound arsenic(V) and iron(Ⅲ) oxides on arsenic release. Our results suggested that As(V) reduction occurred prior to Fe(Ⅲ) reduction, and Fe(Ⅲ) reduction did not enhance the release of arsenic. Instead, Fe(Ⅲ) hydroxides retained their dissolved concentrations during the experimental process, even though the new iron mineral-magnetite formed. In contrast, the release of reduced As(Ⅲ) was promoted greatly when aluminum hydroxides was incorporated. Thus, the substitution of aluminum hydroxides may be responsible for the release of arsenic in the contaminated soils and sediments, since aluminum substitution of Fe(Ⅲ) hydroxides universally occurs under natural conditions.     

塔里木盆地气溶胶粒度分布研究

使用Series 210收集了塔里木盆地内6个不同地点的气溶胶,获取了该地区气溶胶的粒度分布,并计算了对应的气溶胶数量中位直径。研究发现:在自然情况下,气溶胶分布遵循双峰分布的规律,其中第一峰值通常出现在0.5μm附近,第二峰值出现在3μm附近;由于采样点的气象条件、地表情况等差异所致,不同采样地点的峰位和峰面积有一定的差异;各采样点气溶胶分布规律显示,绝大多数气溶胶粒子粒径小于1μm。自然条件下,大多数采样点气溶胶粒子数量中位直径小于1μm。     

气溶胶在不同倾角裂隙中穿透率研究

为研究气溶胶在自然界不同倾角岩体裂隙中的穿透率,对理想模型进行了理论分析计算,并在实验室用钢板制做模拟裂隙置于不同角度进行实验。结果表明:实测值与修正后的理论计算值吻合较好,对于有一定倾角的规则尺寸岩体裂隙可以通过修正后的理论计算公式得到气溶胶在其中的穿透率;随着水平倾角的交替改变(-90°~90°),气溶胶穿透率呈现周期性变化,随着相对角度(0°~90°,0°~-90°)的增加,气溶胶穿透率明显上升,且大粒径粒子尤为明显,小粒径粒子受角度影响较小;随着侧面倾角增大(0°~90°),气溶胶粒子穿透率逐渐上升(尤其是大粒径气溶胶粒子);裂隙呈水平状态时,气溶胶在其中的穿透率最低。裂隙倾角变化,对小粒径气溶胶粒子穿透率影响不大,对大粒径气溶胶粒子穿透率影响较为明显。     

Bacterial community succession during the enrichment of chemolithoautotrophic arsenite oxidizing bacteria at high arsenic concentrations

To generate cost-effective technologies for the removal of arsenic from water, we developed an enrichment culture of chemolithoautotrophic arsenite oxidizing bacteria (CAOs) that could effectively oxidize widely ranging concentrations of As(III) to As(V). In addition, we attempted to elucidate the enrichment process and characterize the microbial composition of the enrichment culture. A CAOs enrichment culture capable of stably oxidizing As(III) to As(V) was successfully constructed through repeated batch cultivation for more than 700 days, during which time the initial As(III) concentrations were increased in a stepwise manner from 1 to 10-12 mmol/L. As(III) oxidation activity of the enrichment culture gradually improved, and 10-12 mmol/L As(III) was almost completely oxidized within four days. Terminal restriction fragment length polymorphism analysis showed that the dominant bacteria in the enrichment culture varied drastically during the enrichment process depending on the As(III) concentration. Isolation and characterization of bacteria in the enrichment culture revealed that the presence of multiple CAOs with various As(III) oxidation abilities enabled the culture to adapt to a wide range of As(III) concentrations. The CAOs enrichment culture constructed here may be useful for pretreatment of water from which arsenic is being removed.     

2010年1月北京城区大气消光系数重建及其贡献因子

于2010年1月1～31日在北京城区每天采集PM2.5样品.利用热光碳分析仪、离子色谱和X荧光光谱仪分别分析样品中有机碳/元素碳、水溶性离子和土壤元素,同步收集了大气散射系数(bsp)、吸收系数(bap)和气象数据.利用IMPROVE方程重建大气消光系数,并与实测大气消光系数进行对比.结果发现,PM2.5日均值质量浓度为(144.3±89.1)μg.m-3,实测值bap、bsp和消光系数(bext)分别为(67.4±54.3)、(328.5±353.8)和(395.9±405.2)Mm-1.IMPROVE方程适用于观测期间北京大气消光系数的解析.观测期间计算值b’ext均值为(611±503)Mm-1,(NH4)2SO4、NH4NO3、OM、EC和FS对b’ext的贡献分别为24.6%、11.6%、45.5%、11.9%和6.4%.     

江苏省大雾持续时间及相关要素的周末效应

使用1996-2006年共11年南京、淮安、徐州、赣榆、射阳、东台、吕泗、溧阳8站大雾持续时间、气温、湿度、风速等资料进行周末效应的研究,结果表明:大雾持续时间存在明显的周末效应,并和风速、相对湿度的周末效应相一致,即在周末风速较小、湿度较大。通过对2001-2006年南京市用电量进行分析,发现其存在明显的周末效应,即在周六、周日陡然下降,在周一大幅上升,表明人类活动具有7天的短周期循环,同时发现大雾持续时间和用电量的周末效应是一致的,说明人类活动和大雾持续时间存在着一定的因果关系。使用南京市2001-2006年可吸入颗粒物浓度资料进行要素周末效应的研究,结果表明大雾持续时间也与气溶胶浓度存在着的显著的周末效应相一致。文章认为,人类活动导致周末气溶胶浓度增大,从而使大雾在周末持续时间延长,影响人类生活,体现了人类活动和高影响性大雾天气的相互作用。     

重庆典型灰霾天气下大气气溶胶的激光雷达探测

简要介绍了法国Losphere公司ALS300型偏振Mie散射激光雷达的基本结构、探测原理及反演算法,并通过在重庆主城区2009年11月23～27日一次典型灰霾天气条件下连续的气溶胶激光雷达探测结果分析得出,重庆冬季典型灰霾天气下PBL平均高度约为600米,AOD值在4及以上。