铅锌矿渣中汞的渗滤特性及其在稻田土壤中的迁移转化特征

关于雨水淋溶作用下铅锌矿渣中汞的渗滤特性及其在稻田土壤中的迁移转化特征并不清楚,本研究利用铅锌矿渣和未受污染的稻田土壤构建微宇宙环境系统,探究其相关特性/征。结果表明,渗滤液中汞的浓度随降雨量的增加而逐渐上升,不同降雨量条件下渗滤液中汞的浓度存在显著差异(p<0.05);一级动力学方程和DoseResp模型均能较好地拟合汞的渗滤过程;在矿渣影响下,不同深度稻田土壤中汞的浓度均显著增加,且随时间的推移呈逐渐升高的规律,0～8、8～15和15～20 cm土壤中汞的垂向迁移速率分别为8.8×10^-4～2.2×10^-3、2.3×10^-4～4.1×10^-4和3.0×10^-7～8.1×10^-5 mg/(kg·cm·d);在矿渣影响下,土壤中残渣态汞的比例下降,其余形态汞的比例均出现不同程度上升,说明在铅锌矿渣影响下稻田土壤汞的生态风险升高。研究结果可为铅锌矿区生态环境保护提供研究基础。     

微波消解-原子吸收/原子荧光光度法测定活性污泥中的Cd、Pb、Ni、Cu、 Zn、Cr、K、As、Hg

通过实验,建立了活性污泥中金属和重金属的测定方法。活性污泥样品经硝酸—氢氟酸或硝酸—高氯酸微波消解处理后,Pb、Ni、Cu、Zn、Cr、K选用火焰原子吸收分光光度法测定,Cd用石墨炉原子吸收分光光度法测定,As、Hg用原子荧光光度法测定。该方法操作简单,结果准确,重现性好。样品加标回收率为93%-108%,相对标准偏差〈5%。     

废水中汞离子去除方法的研究进展

基于国内外研究文献结合自身最新研究工作,论述了去除工业废水中汞离子的化学沉淀法、微电解混凝沉淀法、吸附法等方法及其作用原理,并分析了各种方法的优缺点;指出了吸附法对含极低浓度汞离子废水的深度处理具有明显的优势。近年来合成的新型导电性聚芳香胺对汞离子初始质量浓度为十至数百mg／L的溶液中汞的去除率在99．99％以上,在含汞工业废水处理中显示出了广阔的应用前景。     

医院用汞对市政污水中汞的贡献

对经市政管网排入高碑店污水处理厂的医疗行业污水进行汞来源的调查研究.根据抽样定律确定了医院采样点的数量和位置,利用原子荧光光度计测定采样点的汞含量,并根据采样点的排水量计算采样点的汞排放量.利用线性回归的方法建立汞排放量与医院床位数和门诊量的线性模型.结果表明:高碑店流域医疗行业汞排放总量为58.27 g/d,对高碑店污水处理厂进水汞的贡献率为5.48%,表明医疗行业对于高碑店污水处理厂进水汞的贡献并不是主要因素,要进行市政污水中汞来源的全面调查,必须对其他行业进行深入研究.对医院行业污水汞的减排提出了对策和建议.      

株洲夏季大气中气态总汞浓度特征

为研究株洲市夏季优良天气下大气中气态总汞(TGM)的浓度特征,于2013年8月利用大气汞分析仪(2537X,加拿大)进行了20 d的连续在线观测。结果显示,实验期间株洲市大气TGM的平均浓度为(4.20±3.37)ng/m3,中值浓度为3.40 ng/m3,高于背景地区和沿海城市,略低于国内其他重点城市。晴天、阴雨天TGM浓度分别为3.59、7.96 ng/m3。晴天TGM浓度具有一定日变化规律,最高值出现在早上7:00~9:00,之后逐渐降低,17:00出现最低值;TGM白天和夜间浓度分别为3.57、3.62 ng/m3,昼夜变化不大。晴天TGM与一次污染物SO2、CO、NO2具有显著的正相关性,与O3呈显著负相关性。株洲市夏季主导风向为东南风,该方向没有明显污染源,西北方向风向频率较低,但TGM浓度明显升高,其主要来源可能是位于西北方向的清水塘工业区。     

中国滨海湿地土壤汞空间分布及影响因素

通过对7个典型滨海湿地土壤（0～20cm）中总汞含量及土壤理化性质、气候以及社会经济因素的测定收集,研究了滨海湿地土壤中汞的空间分布规律和影响因子之间的关系,并对不同介质环境内汞含量进行分析.结果表明:我国滨海湿地土壤总汞的含量范围是1.26～169.94ng/g,平均值为（33.82±3.09） ng/g;滨海湿地土壤汞含量差异是由土壤理化性质、社会经济以及气候因素共同影响的结果,其中土壤理化性质中pH值、有机质、总铁、总氮为关键影响因素;在汞的输入途径中,河流输送对中国滨海湿地土壤总汞含量的影响要高于大气输送.     

Simultaneous removal of gaseous CO and elemental mercury over Cu-Co modified activated coke at low temperature

Cu-Co multiple-oxides modified on HNO₃-pretreated activated coke (AC_N) were optimized for the simultaneous removal of gaseous CO and elemental mercury (Hg⁰) at low temperature (< 200 °C). It was found that 2%CuOx-10%CoOx/AC_N catalyst calcined at 400°C resulted in the coexistence of complex oxides including CuO, Cu₂O, Co₃O₄, Co₂O₃ and CoO phases, which might be good for the simultaneous catalytic oxidation of CO by Co-species and removal of Hg⁰ by Cu-species, benefiting from the synergistic catalysis during the electro-interaction between Co and Cu cations (CoO ? Co₃O₄ and Cu₂O ? CuO). The catalysis removal of CO oxidation was obviously depended on the reaction temperature obtaining 94.7% at 200 °C, while no obvious promoting effect on the Hg⁰ removal (68.3%-78.7%). These materials were very substitute for the removal of CO and Hg° from the flue gas with the conditions of 8–20 vol.% O₂ and flue-gas temperature below 200 °C. The removal of Hg° followed the combination processes of adsorption and catalytic oxidation reaction via Langmuir-Hinshelwood mechanism, while the catalysis of CO abided by the Mars-van Krevelen mechanism with lattice oxygen species.     

Monitoring Inter-Annual Variability Reveals Sources of Mercury Contamination in Clear Lake, California

Mercury (Hg) in the aquatic ecosystem of Clear Lake has been documented since the 1970s when fishes were found to have elevated levels of toxic methyl mercury (meHg). Mining practices at the Sulphur Bank Mercury Mine (active intermittently from 1872–1957) along the shoreline of Clear Lake included the bulldozing of waste rock and overburden ore into the shallow nearshore regions of the lake and the creation of steeply sloped piles of waste rock at the water's edge. This process, plus erosion of the waste rock piles, resulted in the accumulation of an estimated 100 metric tons of Hg in Clear Lake. A monitoring program to assess Hg in Clear Lake was established in 1992, and conducted continuously from 1994. Drought conditions in California had persisted for ca. 6 yrs prior to 1992, when the U.S. Environmental Protection Agency (USEPA) remediated the steeply sloped eroding waste rock piles, which appeared to reduce sediment Hg concentrations significantly. In April 1995, a white flocculent material was observed in Clear Lake adjacent to the mine and has been observed every year since, leading to the discovery of ongoing acid mine drainage (AMD), low pH fluids high in Hg and extremely high in sulfate. AMD is now believed to be the most likely cause of elevated meHg in Clear Lake. The discovery of this source of meHg production in Clear Lake, which will significantly influence remedial options, was only made possible by implementation of a diligent monitoring program.     

京杭大运河(苏北段)底泥中汞的总量与形态的分布研究

对京杭大运河(徐州段)底泥中的18个样品进行研究,分别用冷原子荧光仪和总有机碳测定仪测定,对底泥中的汞的总量和形态进行测定.结果表明,汞在底泥中的含量主要以残渣态存在,可交换态很少,占总合量的0.04%～1.839%,总有机碳的含量与汞的总量分布没有相关性.     

环境监测实验室水中砷、汞监测能力考核结果评价

报道了全国环境监测系统136个实验室地表水中As、Hg监测能力考核的结果。采用四分位稳健统计法处理各实验室的测定数据,砷和汞结果均满意的实验室为101家。分析了各实验室质量管理体系运行中存在的问题,质控环节的问题是质量体系运行中较为突出的问题。提出了综合数据结果和质量体系运行情况进行结果评价的方法。