淮河淮南段底泥中酸性挥发硫与同步浸提金属的分布

采用氮载气冷法酸溶硫化物分析技术对淮河淮南段底泥中酸性挥发硫(AVS)以及同步浸提金属(SEM)的含量在河流沿程及垂直方向上的分布进行了测定.结果表明,淮河淮南段5个站点表层底泥中AVS的含量为0.14～0.87 μmol·g-1SEM(Zn、Cu、Ni、Cd、Pb)含量为0.5～1.1 μmol·g-1;其中,峡山口站点AVS最低,姚家湾站点AVS及SEM均为最高;从入境到出境断面,[SEM]/[AVS]摩尔比值呈逐渐下降趋势,数值都在1.0以上.不同站点AVS在垂直方向上的分布较为复杂,峡山口25 cm以上段随深度增加AVS逐渐增大.之后又逐渐降低,30 cm以下段变化很小;姚家湾表层AVS含量较高,20 cm以上段随深度增加AVS逐渐减小,之后又逐渐增大,30～35 cm层含量最高;石头埠和胡大涧站点AVS随深度变化不大.胡大涧以上4个站点柱状底泥中SEM的含量在0.25～0.9 μmol·g-1之间.对[SEM]/[AVS]摩尔比的研究显示,淮河淮南段表层底泥存在轻微的重金属污染.     

化学沉淀法去除电镀废水中铬的实验研究

文章采用化学沉淀的方法处理含铬电镀废水,以FeSO4还原电镀废水中的Cr6+,转化为危害较小的Cr3+,并通过调pH使之形成Cr(OH)3沉淀。反应过程中涉及的影响因素有还原剂投加量、Cr6+被还原时的pH值、转化为Cr3+时的pH值、电镀废水中Cr的初始浓度等。通过实验研究获得了上述影响因素的最佳参数值。最后实验效果表明:化学沉淀法能够快速、有效地去除电镀废水中的铬,总铬去除率在90%左右。     

土壤汞的地球化学行为及其污染的防治对策

综述了土壤汞的来源 ,以及汞在土壤中的迁移方式、转化模式和富集行为 ,并介绍了当前几种土壤汞污染的防治对策 ,重点讨论了改进农耕技术、减少人为活动向大气的排汞量、生物修复以及电解法等方法 ,最后对土壤汞的研究方向进行了展望。     

Effects of co-exposure to lead and manganese on learning and memory deficits

Lead (Pb) and manganese (Mn) are common neurotoxins. However, individuals are subject to co-exposures in real life, and it is therefore important to study these metals in combination. Weaning Sprague-Dawley rats were given ad libitum access to drinking water solutions containing Pb (100 mg/L), Mn (2.5 mg/mL) or a mixture, and each treatment had its own minocycline (50 mg/(kg•day)) supplement group. The results showed a significant difference in spatial memory and induction levels of hippocampal long-term potentiation (LTP) in all exposure groups when compared with controls. The combined-exposure group exhibited the most pronounced effect when compared with each of the single-metal exposure groups. Microglia displayed activation at day 3 after exposure alone or in combination, while astrocytes showed activation at day 5, accompanied by decreased expression levels of GLAST, GLT-1, and GS. Furthermore, the levels of glutamate in the synaptic cleft increased significantly. When microglial activation was inhibited by minocycline, the activation of astrocytes and the expression of GLAST, GLT-1, and GS were both reversed. In addition, upon minocycline treatment, hippocampal LTP impairment and cognitive injury were significantly alleviated in each of the exposure groups. These results suggest that combined exposure to Pb and Mn can cause greater effects on cognition and synaptic plasticity when compared to single-metal exposure groups. The reason may involve abnormal activation of microglia leading to excessive regulation of astrocytes, resulting in glutamate reuptake dysfunction in astrocytes and leading to perturbed cognition and synaptic plasticity.     

改性膨润土粉末对克百威的吸附

分别用季铵盐阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)和阴离子表面活性剂十二烷基苯磺酸钠(SDBS)改性钠基膨润土,研究改性膨润土吸附水中氨基甲酸脂类农药克百威的效果、机理及主要影响因素。结果表明,改性膨润土的有机碳含量和用土量影响其对克百威的吸附去除率。表面活性剂通过插层进入膨润土间,有效扩张了膨润土的层间距,有机插层效果明显。100CTMAB-10SDBS膨润土为最佳的吸附剂类型,最佳用土量20.00 g/L,吸附平衡时间为3 h,平衡去除率为92.60%。改性膨润土对克百威的吸附符合Freundlich模型,变形公式的相关系数在98%以上。     

基于危害性分级的地下水污染源分类识别方法

地下水污染源分类识别是有序开展地下水污染防控工作的前提。以典型地下水污染源为研究对象,建立综合考虑优控污染物、污染源特征的地下水重点污染源识别指标体系,以污染源危害性评价结果作为重点污染源的判别依据。将哈斯(Hasee)图解法与综合评分法相结合,用于地下水优控污染物识别,同时引入修正的内梅罗综合污染指数法,对多组分的地下水优控污染物开展综合评价,并选择3个典型地下水污染源进行分类识别方法实地验证。结果表明:污染源S1、S2和S3的危害性等级分别为Ⅲ、Ⅲ、Ⅱ。在区域地下水污染分类防控与分级管理中,应对危害性等级较高的污染源S1和S2加以重点关注。     

赣南稀土矿区地下水污染现状、危害及处理技术与展望

赣南稀土矿区由于受离子型稀土矿开采的影响,地下水污染严重。在查阅国内外相关文献的基础上,阐述了赣南稀土矿区矿山开采和原地浸矿导致的地下水稀土元素、三氮(离子态的氨氮、亚硝酸盐氮和硝酸盐氮)和硫酸盐污染现状,分析了该类型地下水污染的危害,总结目前已有的地下水修复方法并分析其应用局限性,提出适用于赣南稀土矿区的地下水污染治理思路。     

Characterization of disinfection byproduct formation potential in 13 source waters in China

The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg m), showed that the organic compounds in di erent source waters exhibited di erent reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 g/L and the THMFP ranged from 29 to 259 g/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 g/L.     

膜萃取处理水溶液中镉、锌离子的传质模型

通过测量中空纤维膜器管程和壳程RTD曲线,发现对于中低装填密度的膜器,管程的实际流动与理想层流有较大差异,而壳程的流动与理想层流符合较好,膜器管程和壳程流动RTD曲线的平均停留时间的实验值与理论值相差很小,停留时间相对偏差小于±5%.通过计算,得出与实际RTD曲线符合较好的速度分布公式,依据镉离子传质数据,提出了较为准确的低流速下的传质系数预测关联式,并用此关联式预测锌离子的出口浓度,预测值与实验值符合较好,相对偏差在±25% 以内.     

泉州湾景观格局分析及动态变化研究

基于GIS技术和景观生态学原理及方法,获得泉州湾1975年、1989年、2001年及2008年四期的景观格局分布图,分析了泉州湾30多年来景观格局的动态变化过程.结果表明:(1)在30余年中,泉州湾自然景观面积明显萎缩,其中滩涂面积减少了2913.09 hm2,减少率为28.7%,人工景观(主要为建设用地)面积增加明显...