Impacts of leachate of landfill on the groundwater hydrochemistry and size distributions and heavy metal components of colloids: a case study in NE China

Environmental Science and Pollution Research - Colloids associated with heavy metals are ubiquitous in contaminated groundwater; waste accumulation at imperfectly sealed landfills can produce large...     

水生植物生态修复重金属污染水体研究进展

综述了挺水植物、漂浮植物、浮叶植物、沉水植物等4种水生植物在生态修复重金属污染水体领域的进展,重点阐述了水生植物对重金属的蓄积效果以及生态修复的影响因素,总结了水生植物生态修复的适用范围和不足,并简要介绍了水体中的重金属通过水生植物进入食物网的生态过程,最后展望了提升水生植物蓄积重金属能力的研究方向。     

Profiles and risk assessment of phthalate acid esters (PAEs) in drinking water sources and treatment plants,East China

This study is the first report describing the occurrence of 15 phthalate acid esters (PAEs) in the three typical water sources of YiXing City, Taihu Upper-River Basin, East China. The fate of target PAEs in the Jiubin drinking water treatment plant (JTP) was also analyzed. The amounts of Σ₁₅PAE in the Hengshan (HS), Youche (YC), and Xijiu (XJ) water sources were relatively moderate, with mean values of 360, 357, and 697 ng L⁻¹, respectively. Bis(2-ethylhexyl) phthalate (DEHP) dominated the PAE concentration, making up 80% of the 15 total PAEs. The highest levels of Σ₁₅PAE were found in HS, YC, and XJ in March 2015, January 2015, and July 2014, respectively. The occurrence and concentrations of these compounds were spatially dependent, and the mean concentrations of Σ₁₅PAE in HS, YC, and XJ samples increased from the surface layer to the bottom layer with varied percentage increases. The removal efficiency of the PAEs in the finished water varied markedly, and the removal of PAEs by the JTP ranged from 12.8 to 64.5%. The potential ecosystem risk assessment indicated that the risk of PAEs was relatively low in these three water sources. However, risks posed by PAEs due to drinking water still exist; therefore, special attention should be paid to source control in the JTP, and advanced treatment processes for drinking water supplies should be implemented.

     

物元分析法在土壤重金属污染评价中的应用

针对实际中的土壤重金属污染状况是渐变的、模糊的,采用物元分析模型法通过建立物元矩阵,引用毒性响应系数对模型中权重的计算方法进行改进,并将改进的物元分析模型对广西环江某受铅锌矿影响的土壤重金属污染状况进行评价分析。结果表明,该区域土壤受重金属污染严重,尤其受Pb、Cd的影响更为严重,此评价结果符合当地的实际情况,同时与潜在生态危害指数评价结果一致,说明物元分析法在土壤重金属污染评价中的应用是合理的,其评价结果具有可靠性。     

闽江河口表层水体氧化亚氮释放时空变化特征及其影响因素

以闽江口水体为研究对象,研究了闽江河口上段(城市河口段)、河口中段和河口下段(口外海滨段)不同季节水体N₂O的溶存浓度、水-气界面通量及其环境影响因子.结果表明,闽江口水体N₂O溶存浓度为0.99～55.92 nmol·L^-1,N₂O饱和度为8.0%～396%,水-气界面N₂O释放通量为-5.21～7.91μg·m^-2·h^-1.从季节差异看,7月(夏季)、9月(秋季)和12月(冬季)水体中N₂O过饱和,表现为N₂O的排放“源”;4月(春季)水体中N₂O不饱和,表现为N₂O“汇”.水-气界面N₂O释放通量呈夏、秋和冬季高,春季低的季节变化规律.在空间变化上,水-气界面N₂O释放通量从河口上段到下段降低,与氮含量变化趋势一致.N₂O间接性释放因子为0.004%～0.128%,低于IPCC...     

硫酸盐还原菌介导水铁矿相转化特征及其产物对Cr（Ⅵ）固存的影响

硫酸盐还原菌(SRB)广泛存在于酸性矿山废水(AMD)污染的土壤中,其介导的铁矿物转化过程及其相转化产物影响着重金属的迁移转化行为.选取土壤中的典型铁氧矿物水铁矿作为研究对象,探究了SRB (Desulfovibrio vulgaris ATCC 7757)介导水铁矿的矿相转化,分析了水铁矿相转化产物对Cr(Ⅵ)的固存能力,揭示了不同相转化阶段产物对六价铬(Cr(Ⅵ))的固存能力及作用机制.结果表明,SRB介导下矿物的相转化路径为水铁矿-马基诺矿-磁铁矿,反应过程的相转化产物对Cr(Ⅵ)的固存能力呈先增加后降低的趋势：反应第5 d水铁矿相转化的产物主要为马基诺矿,此阶段相转化矿物对Cr(Ⅵ)的固存能力达到141.06 mg·g^-1,固存方式以还原作用为主;14 d时相转化矿物主要以马基诺矿和磁铁矿复合形式存在,复合产物对Cr(Ⅵ)的固存能力仅为79.59 mg·g^-1,其对Cr(Ⅵ)的固存方式包括还原和吸附作用,还原和吸附对Cr(Ⅵ)固存的贡献占比分别为78.82%和21.17%.由此可见,水铁矿相转化产物组成的差异是导致其对Cr(Ⅵ)固存能...     

TiO2-PW9复合催化剂光催化降解游离氰

采用水热法制备了二氧化钛(TiO_2)与三缺位磷钨酸钠(Na_8H[β-A-PW_9O_(34)]·24H_2O)共价结合形成的TiO_2-PW_9复合催化剂,并对其光催化降解游离氰(CN~-)的效果进行了研究.NMR和XPS等表征结果证明,Na_8H[β-A-PW_9O_(34)]·24H_2O(简写为Na-PW_9)已成功负载于TiO_2上.光电化学表征结果表明,Na-PW_9的引入可有效提高TiO_2的界面电荷转移.光催化实验结果表明,与单独TiO_2相比,TiO_2-PW_9的光催化活性有明显提高.同时,探究了初始CN~-浓度和催化剂投加量对CN~-去除的影响.结果表明,当初始CN~-浓度为0.3 mmol·L~(-1)、催化剂投加量为1 g·L~(-1)时,复合催化剂的光催化活性最佳,反应150 min后,CN~-的去除率达到81%.CN~-的氧化产物分析结果表明,氰酸根(CNO~-)是CN~-氧化的唯一产物.自由基淬灭实验和电子自旋共振(ESR)波谱分析结果表明,~1O_2是反应体系中的主要活性氧物种.本实验可为多功能催化材料的开发及其在含氰废水污染控制领域的应用提供参考.     

稀土矿区土壤和蔬菜稀土元素含量及其健康风险评价

通过野外取样调查和室内ICP-MS测定,研究了福建省长汀县稀土矿区蔬菜地土壤(0 ～20 cm)及主要蔬菜中稀土元素的含量,同时评价了食用蔬菜对人体可能产生的健康风险.结果表明,蔬菜地土壤中稀土元素平均含量高于福建省背景值,芋头和空心菜中稀土元素的平均含量分别为3.68和0.92 mg·kg-1(鲜重),超过了蔬菜卫生标准限值(0.7 mg·kg-1).8种蔬菜中稀土元素含量的大小:芋头＞空心菜＞生菜＞上海青＞豆角＞茄子＞白萝卜＞大白菜;除芋头外,一般为多叶绿色蔬菜的稀土元素含量较高,而无叶蔬菜含量较低.矿区居民血液和头发中稀土元素的平均含量高于正常人,超标量达155.6和9.6倍,井水中稀土元素的平均含量是福州市饮用水的119倍.当地居民通过蔬菜和井水摄入的稀土元素终生日平均量为12.4699 mg·kg-1·d-1,超过稀土对人体亚临床损害剂量的临界值(6.0 ～6.7 mg·kg-1·d-1),当地居民面临着较大的健康风险.部分蔬菜对土壤中稀土元素具有较大的吸收和累积量,因此,当地居民应选择具有低积累量的蔬菜品种,以降低稀土元素对人体健康的危害.     

Information source and valence: How information credibility influences earthquake risk perception

The present research aims at the relationship between information credibility and perception of seismic risk in a group of people living in severe disaster areas. 243 adult residents exposed to seismic hazard participated in a questionnaire study. With respect to four types of information which are generated by information sources and valence, participants were instructed to recall one type of the information they obtained respectively and rate the recalled information in terms of its credibility. After that, they were asked to report their seismic risk perception and all socio-demographic data were also collected. Regression analyses suggested that information credibility significantly influenced risk perception. Furthermore, the credibility of word-of-mouth and negative information were positively associated with risk perception. Meanwhile, risk perception was also affected greatly by the credibility of negative public information but not positive word-of-mouth information. It was clear that both information source and valence moderated the process and the latter exerted a stronger influence on it. The results were interpreted in relation to the elaboration likelihood model, accessibility-diagnosticity model, and other cognitive theories. The findings were discussed in terms of their general implications for the improvement of risk communication about earthquake related messages.     

新型乙醇汽油防静电混合器数值模拟研究

设计了一种新型乙醇汽油防静电混合器,基于CFD方法对新型乙醇汽油防静电混合器及简单的T型管混合器的内部流场分别进行数值分析,通过比较混合器中各组分浓度分布、压力分布、速度分布等特征,研究乙醇与汽油在混合器中的混合效果,并分析静电产生的风险。结果表明：在新型混合器螺旋叶片的作用下,乙醇汽油在出口处几乎混合均匀,速度趋于一致,且压力损失较小,说明新型混合器可以在较小的能耗下获得较好的混合效果,从而有效减少静电积聚。