Hg2+对固定化小球藻污水净化及生理特征的影响

利用褐藻酸钙凝胶包埋固定普通小球藻,对人工配制的含汞污水进行静态净化实验,研究了不同浓度Ｈｇ＾２＋对固定化小球藻净化污水中氨氮,正磷酸盐的效率及其４个生理指标（叶绿素α,光合强度,生长和过氧化物酶）的影响,并与悬浮藻对照比较。结果表明,由于小球藻的固定化增加了对Ｈｇ＾２＋毒性的抗性,０．２×１０＾－６浓度的Ｈｇ＾２＋对其净化效率无多大影响,而悬浮藻的净化明显下降。随着Ｈｇ＾２＋浓度的增加,固定藻的     

伯胺N1923萃淋树脂吸萃汞(Ⅱ)机理的研究

研究伯胺Ｎ１９７３萃淋树脂在萃取剂Ｎ１９２３成盐和不成盐时不吸吸附汞的反应机理,通过等摩尔系列法、斜率法、饱和容量法等确定吸萃物在成盐和非成盐时的组成分别为：（ＲＮＨ３）２ＨｇＣｌ４和（ＲＮＨ）２ＨｇＣｌ２。并通过红外光谱和核磁共振光谱分析吸萃过程中的不同机理,成盐时为离子交换机理,非成盐时为配位机理。     

水环境中汞的形态及其分析方法

概述了近年来国内外对水环境中汞的形态、分离富集手段及其测定方法的研究报道。文献表明随着对汞环境化学行为研究的深入 ,汞的形态分析技术在今后依然是极富挑战的课题。     

中国南方稻田土壤汞含量及潜在危害评价

选择我国南方水稻主产区安徽、浙江、湖南、湖北以及广西5个省,采集213个稻田土壤样品,探究我国南方稻田土壤中汞的空间分布特征与土壤理化参数(如p H值和有机质)的相关关系及汞富集的潜在危害。结果表明:不同省份的稻田土壤汞含量存在显著的差异(P0.05,n=213),含量范围是0.029~0.326 mg·kg~(-1)(干重),平均值为(0.094±0.036)mg·kg~(-1),与农用地土壤环境质量标准0.30 mg·kg~(-1)(GB15618—1995)相比,除湖北省以外均有轻度汞污染。Pearson相关性分析表明,稻田土壤中的汞含量与有机质含量呈显著正相关关系(P0.01,r=0.445),说明适度偏高的有机质有利于土壤汞的富集。不同省份稻田土壤潜在危害等级除浙江省外均在轻微到中等的范围内,浙江省的为强等级。     

用于气态零价汞转化的催化剂研究

零价汞的高效去除是燃煤烟气汞污染控制过程中的关键环节。为了促进烟气中的零价汞转化为易于去除的氧化态汞,分别考察了在有HCl存在时,几种过渡金属氧化物(Cu、Fe、Mn、Co和Zr)对零价汞氧化的催化作用,以筛选出性能较好的催化组分;为提高催化剂的抗SO2性能,分别尝试了利用几种金属元素(Sr、Ce、W和Mo)对催化剂进行掺杂改性的方法。结果表明,锰氧化物的催化作用最好,其最佳使用温度在573 K左右;SO2对零价汞的催化氧化有明显抑制作用,在无SO2及1 400 mg/m3SO2时锰催化剂对零价汞催化氧化效率分别为93%和78%。而Mo改性的锰氧化物催化剂的抗硫性能大幅提高,在1 400 mg/m3SO2存在的情况下其对零价汞的催化氧化效率可达到90%以上,较其他改性元素高。     

改性活性炭纤维吸附脱除气态汞

采用浸渍法对活性碳纤维(ACF)改性,所制得的吸附剂在固定床上进行汞吸附评价。Boehm滴定表明,浓HNO3和H2O2改性后的ACF表面含氧官能团有所增加,含氧官能团的增加有利于汞的吸附。XRF结果表明,ACF经硝酸银浸渍后,银离子被还原成单质银,使其对汞的吸附性能得到改变,并随着硝酸银浓度的增大而增大。ACF经活性MnO2和KMnO4浸渍后,吸附效果均有所提高,穿透时间大大加长,穿透吸附量也大大提高,两者均可达到170μg/g。     

三峡水库175 m蓄水运行后鱼类汞污染风险研究

三峡水库的生态安全受到高度关注,三峡水库成库后是否会出现汞等重金属生态风险增加的“水库效应”,不仅是需要论证的科学命题,也是关系到库区人民身体健康的重要问题。2011年在三峡库区忠县至秭归段选择“湖沼化”特征最为显著的8条支流采集了鲤、鲢、鳙、鲇、鳜等常见经济鱼类标本,系统分析了库区鱼类标本肌肉中的总汞含量。研究结果表明,三峡库区支流鱼类肌肉中总汞含量最高为109.6 μg/kg,最低为30.5 μg/kg,平均含量为56.4 μg/kg。与蓄水前的调查结果相比,蓄水运用10 a后库区鱼类肌肉总汞水平尚未明显增加。但是,不同营养等级鱼类之间,肌肉总汞浓度水平随营养等级增加有明显增高,三峡水库水生食物链表现出显著的汞的生物累积。值得注意的是,底层鱼类汞的生物累积强度明显高于上层鱼类,暗示水库底栖过程的“汞活化”依然是需要关注的潜在生态风险     

Periphyton as a bioindicator of mercury pollution in a temperate torrential river ecosystem

Mercury presents a potential risk to the environment and humans, especially in its methylated form. It is among the highest priority environmental pollutants. River Idrijca (Slovenia) is highly contaminated with mercury due to past mercury mining. The aim of this work was to investigate whether the periphyton community in rivers such as Idrijca is a suitable indicator of Hg pollution and of changes in mercury methylation and could serve as an early warning system of increased input of MeHg in the food chain. Periphyton is the only site of primary production in temperate torrential rivers such as Idrijca and is therefore an important link in the food chain. It is also a potential site of Hg accumulation and its introduction to higher trophic levels. Our aim was to assess the response of the periphyton to seasonal and spatial variations in mercury levels and to evaluate its potential as an early warning system of changes in mercury reactivity and mobilization The results indicate that periphyton in a torrential river is too complex and unpredictable to be used as a sole indicator of mercury concentrations and changes in the river. Nevertheless, it can complement environmental measurements due to its importance in the riverine food web.     

微波消解-氢化物发生原子荧光光度法测定土壤中的汞

建立了微波消解-氢化物发生原子荧光光度法测定土壤中汞的方法。对微波消解条件、样品粒度等进行了优化,用3 mL硝酸和2 mL盐酸的混合酸作消解溶剂,在设定的微波条件下汞提取完全。用3%的盐酸作为反应载流,0.01%硼氢化钾与0.5%氢氧化钠的混合液为还原剂,直接定容后应用HG-AFS测定,通过测定国家标准参考物质和加标回...     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.