黔西北土法炼锌区Pb、Cd污染与生态修复

对黔西北典型的土法炼锌区的冶炼废渣、土壤、河流、地下水、农作物的Pb、Cd进行了分析,结果表明,冶炼废渣中909／5的样品其Pb含量、所有样品的Cd含量超过了GB15618-1995《土壤环境质量标准》二级标准;土壤中40％的样品其Pb含量、所有样品的Cd含量也超过了该标准二级标准。河流中509／5的样品其Pb含量、所有样品的Cd含量超过了GB3838—2002《地表水环境质量标准》Ⅲ类标准,二者含量主要存在于悬浮物中。地下水的重金属污染较轻。污染点白菜的重金属含量大大超过对照点,对该地区居民的健康构成威胁。针对冶炼区的环境污染,提出生态修复对策：1）植被重建;2）植物提取修复。     

Cd^（2＋）、Zn^（2＋）在不同介质中的等温吸附及迁移特性

采用等温吸附实验和土柱实验,探讨了重金属镉、锌在青岛地区三种主要土壤（棕壤、潮土和砂浆黑土）中的静态吸附特征和在石英砂、石英粉中的动态迁移特性。在静态等温吸附实验中,棕壤和潮土对Cd^2＋、Zn^2＋的吸附量相近,而黑土对Cd^2＋、Zn^2＋的吸附量明显高于棕壤和潮土。Cd^2＋、Zn^2＋的吸附比率随着加入浓度的增加而减少。在动态迁移实验中,Cd^2＋、Zn^2＋的迁移特性受介质质地、加入浓度、背景浓度和pH值的影响。由实验可知：Zn^2＋的迁移性比Cd^2＋强;随着pH的升高,介质对重金属的吸附容量和固持力增加。     

Enhanced adaptability of Sesbania rostrata to Pb/Zn tailings via stem nodulation

Sesbania rostrata is wellknown for its stem nodulation, but the roles of stem nodulation in root nodulation and adaptation of S. rostrata to Pb/Zn-enriched tailings environment has been poorly understood. We investigated the e ects of inoculating (with stem nodule treatment) and non-inoculating (without stem nodule treatment) Azorhizobium caulinodans on the growth, root nodulation, and N fixation of S. rostrata grown on three di erent types of soil substrata: Pb/Zn tailings, garden soil amended tailings, and garden soil. The results showed that plant height, stem basal diameter, biomass, chlorophyll content, nitrogen content and N-accumulation per plant were 2.3%–4.9%, 2.2%–7.7%, 27.8%–72.2%, 17.1%–23.5%, 12.3%–34.2%, and 43.1%–131.2%, respectively, higher in treatments with stem nodule than those without stem nodule for the same soil substrate. With respect to soil substrata, all measurements had consistently higher values in tailings than in amended tailings and garden soil, indicating that the poorer the soil condition, the greater the contribution of stem nodule. In contrast, the number and fresh weight of root nodules on plants without stem nodule were 6.9–11.6 times and 5.8–29.0 times higher than those with stem nodule, respectively, especially with respect to the plants grew on Pb/Zn tailings. In general, stem nodulation favored plant growth and nitrogen fixation of S. rostrata, but suppressed root nodulation. With the ability of stem and root nodulation, S. rostrata can be used as a pioneer plant species for remediation of Pb/Zn tailings.     

酸浸法由废旧锌锰电池制取碳酸锰的研究

利用湿法回收技术,对废旧锌锰电池中的锰进行回收处理,制取MnCO3。实验表明,HCl和HNO3的浓度、所用体积以及浸泡时间对MnCO3的产率影响较大。当HCl的浓度为5mol/L、体积为40mL、浸泡时间为180min时,MnCO3的产率可达64.85%;HNO3的浓度为6mol/L、体积为60mL、浸泡时间为80min时,MnCO3的产率可达63.76%。     

Biosorption of mercury by Macrocystis pyrifera and Undaria pinnatifida: Influence of zinc, cadmium and nickel

The article investigated the adsorption of Hg(II) on Macrocystis pyrifera and Undaria pinnatifida in monometallic system and in the presence of Zn(II), Cd(II) and Ni(II).     

Seedling growth and metal accumulation of selected woody species in copper and lead/zinc mine tailings

A greenhouse pot experiment was conducted to evaluate the potential of selected woody plants for revegetation in copper (Cu) and lead/zinc (Pb/Zn) mine tailing areas. Five woody species (Amorpha fruticosa Linn, Vitex trifolia Linn: var. simplicifolia Cham, Glochidion puberum (Linn.) Hutch, Broussonetia papyrifera, and Styrax tonkinensis) and one herbaceous species (Sesbania cannabina Pers) were planted in Cu and Pb/Zn tailings to assess their growth, root morphology, nutrition uptake, metal accumulation, and translocation in plants. Amorpha fruticosa maintained normal growth, while the other species demonstrated stress related growth and root development. Sesbania cannabina showed the highest biomass among the plants, although it decreased by 30% in Cu tailings and 40% in Pb/Zn tailings. Calculated tolerance index (TI) values suggested that A. fruticosa, an N-fixing shrub, was the most tolerant species to both tailings (TI values 0.92–1.01), while S. cannabina had a moderate TI of 0.65–0.81 and B. papyrifera was the most sensitive species, especially to Pb/Zn tailings (TI values 0.15–0.19). Despite the high concentrations of heavy metals in the mine tailings and plants roots, only a small transfer of these elements to the aboveground parts of the woody plants was evident from the low translocation factor (TF) values. Among the woody plants, V. trifolia var. simplicifolia had the highest TF values for Zn (1.32), Cu (0.78), and Pb/Zn (0.78). The results suggested that A. fruticosa and S. cannabina, which have the highest tolerance and biomass production, respectively, demonstrated the potential for tailings revegetation in southern China.     

"南海贻贝观察":广东沿海牡蛎体中Zn含量水平及其变化趋势

为了了解广东沿海重要养殖水域Zn含量水平变化趋势,1989～1997年间实施"南海贻贝观察"计划对广东12个地点牡蛎体的Zn含量进行了连续监测.广东沿海牡蛎体Zn含量范围为50.4×10-6～768×10-6,总平均值为245×10-6,总体上属清洁～微污染水平.牡蛎体Zn含量的海域分布格局呈珠江口海区＞粤东海区≥粤西海区.1989～1991年,广东沿海牡蛎体Zn含量呈上升趋势,此后略微下降,1994～1997年间牡蛎体Zn含量虽有波动,但年际间没有明显差异.     

加拿大发布6项偶氮金属筛查评估

正2014年5月20日来源:Chemical Watch网站加拿大规制部门开始就它们认定6种偶氮金属配合物和物质不构成《加拿大环境保护法》(CEPA)定义的环境或健康威胁的决定征求公众评议。针对偶氮基团的快速筛查评估是加拿大对其《国内物质清单》上的优先性物质进行评估的工作的一部分。在确定这些配合物和物质不满足将要求进行进一步研究或更严格规制的任何标准前,环境和卫生主管部门已经发现,所有6种偶氮物质的国内生产量均不足以触发进一步评估。只有一种基于C10-14烷基胺的     

贵州西部土法铅锌矿区不同类型废渣重金属的释放特征

贵州省西北部水城-赫章铅锌矿带是贵州铅锌的主要产地,其中赫章县是我国著名的土法炼锌集散地,土法炼锌已有300多年历史.铅锌矿的开采导致大量含硫化物矿物的矿渣及尾矿等暴露于地表,在氧化作用、淋滤作用及地表水的     

吃核桃的好处

核桃,又称胡桃,为胡桃科植物。核桃仁含有丰富的营养素,每百克核桃含蛋白质15～20克、脂肪60～70克、碳水化合物10克,并含有人体必需的钙、磷、铁等多种微量元素和矿物质,以及胡萝卜素、核黄素等多种维生素。核桃中所含脂肪的主要成分是亚油酸甘油脂,食后不但不会使胆固醇升高,还能减少肠道对胆固醇的吸收,因此可作为高血压、动脉硬化患者的滋补品。此外,这些油脂还可供给大脑基质的需要。核桃中所含的微量元素锌和锰是脑垂体的重要成分,常食有益于脑的营养补充,有健脑益智作用。