Investigations on simultaneous determination of silverand mercury in catalytic-ligand substitutionreaction with stopped - flow techniquecalibrated by synergistic effect

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冷原子吸收法测定汞过程中的质量控制

文章对影响冷原子吸收法测定汞的有关因素进行了研究和探讨,以提高测定准确度和精密度。     

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。     

水中痕量汞的定量分析方法研究

选用氢化物发生-原子荧光光度法(HGAFS)进行水中痕量汞的定量分析，研究了HGAFS法测定汞的各种影响因素，确定了最佳工作条件。在此条件下，仪器稳定性好、灵敏度高、检出限低，可以直接对天然水中的痕量汞进行准确测定。     

汞对蔬菜幼苗生长及氧化酶同工酶的影响

汞是城市污水中的一种主要有毒物,郊区农民常用这种污水灌溉农作物,造成减产。含汞工业污水对水稻、小麦种子萌发、幼苗及胚根生长的毒性影响及体内某些酶的变化已有一些报道,但对蔬菜幼苗期形态变化与体内某些酶变化的关系则很少有人探讨。我们用不同浓度汞溶液处理番茄等6种作物种子,探讨其对幼苗生长的影响及体内氧化酶同工酶变化的关系,为生产上早期检测作物受汞害的程度、选择抗汞害的作物品种提供依据。     

两次金汞齐-冷原子荧光光谱法测定大气中的痕量气态总汞

建立了两次金汞齐-冷原子荧光光谱法(CVAFS)测定大气中痕量气态总汞(TGM)的方法。研究表明:本方法的绝对检出限为2 pg;当以0.2~0.4 L·min-1 采样速度,采集12~48 h时,采样效率> 99%,精密度为9.63%;样品经2次循环加热分析,热解吸效率> 99%。这种分析方法还可以运用到其他环境样品痕量汞的测定。     

椭圆小球藻对汞的吸附-解吸探究

以椭圆小球藻（Chlorella ellipsoidea）为试验藻种,探究黑暗环境中活藻、死藻在不同条件下对水中汞的吸附-解吸特征、动力学过程和等温吸附模型。结果表明,椭圆小球藻在弱酸性或中性（pH=3～8）水环境中对汞的吸附能力最强,吸附总量随藻浓度的增加而增加,单位吸附量随藻浓度增加而降低,最佳吸附丰度约为3.2×10⁶ cells/mL,其中活藻处理对汞的最大吸附率为71.2%,死藻处理的最大吸附率为62.9%。椭圆小球藻对汞的吸附主要分为生物吸附和生物富集吸附两个阶段,其中死藻细胞主要以生物吸附为主,活藻细胞除了具备生物吸附以外还可进行生物富集吸附,藻细胞生物富集汞的能力与藻丰度和环境中汞浓度有关。二级动力学方程和Langmuir等温吸附模型可较好地描述椭圆小球藻对汞的吸附过程。在解吸汞的过程中,椭圆小球藻死藻解吸能力更强,活藻在解吸过程中伴随着生物富集,1 440 min后死藻和活藻均可达到解吸平衡。     

污灌区盐分累积对污染土壤汞释放通量的影响

采用优化设计的动态通量箱,对不同盐分（NaCl和Na₂SO₄）和盐度（0~5%）的盐渍化土壤土-气界面的汞交换通量进行动态监测,研究盐渍化对污灌区土壤汞和大气释放的影响.结果表明：（1）两种盐分类型对土壤Hg释放的影响呈相反趋势.与未发生盐渍化的对照土壤相比,随着NaCl盐度梯度的上升,土壤Hg释放通量呈现上升趋势,5%盐度处理下,Hg通量均值与对照相比提高了48.94%;而随着Na₂SO₄盐度梯度的上升,土壤Hg释放通量呈现下降趋势,5%盐度处理下,Hg通量均值与对照相比降低了20.62%.（2）土壤盐分含量与土壤汞释放通量均值之间呈线性关系.对于NaCl,含量x（g/kg）与汞通量y [ng/（m²·h）]之间的模型为y=0.8258x+86.709（R²=0.9734）,对于Na₂SO₄,模型为y=-0.3354x+85.997（R²=0.9581）.从研究结果来看,高浓度的NaCl环境对土壤汞释放通量有显著影响,土壤的盐渍化趋势会使汞释放及作物吸收风险更趋严重.     

Metals in feathers of sooty tern, white tern, gray-backed tern, and brown noddy from islands in the North Pacific

Levels of heavy metals are usuallyhigher in adult than young birds because they eatlarger, more contaminated prey, or because they havehad longer to accumulate metals in their tissues.Further, levels of contaminants are usually less inbirds nesting on remote, offshore islands than inbirds breeding closer to mainland areas that areurbanized and industrialized. We examined the featherlevels of arsenic, cadmium, chromium, lead, manganese,mercury, and selenium in adult sooty terns (Sterna fuscata), gray-backed terns (Sterna lunata), and brown noddy (Anous stolidus, and adult and young white terns (Gygis alba, fromMidway Atoll, and in adult and young sooty terns andadult brown noddy from Manana Island, Hawaii (chicksof other terns were not available). We tested andrejected the null hypotheses that metal levels are notsignificantly different among species, ages, andlocations. Despite their small size, adult white ternshad the highest levels of lead, arsenic and tin. Brownnoddies had the highest levels of cadmium, chromium,manganese, and selenium. Sooty and white terns had thehighest levels of mercury. Sooty tern adults hadsignificantly higher levels of cadmium, mercury, andselenium than young, while young had significantlyhigher levels of arsenic and manganese. White ternadults had significantly higher levels of selenium andtin than young, while young had higher levels ofcadmium and mercury than adults. Except for mercury,there were significant inter-location differenceswithin species in all heavy metals. Contrary toexpectation, where the differences were great, metalsgenerally were higher in the feathers of terns andnoddies from Midway than from Manana.     

清水江水、鱼体和悬浮物中汞的特征及污染评价

为探明清水江水、鱼体和悬浮物中的汞污染情况,采用地质累积指数、单因子污染指数和潜在生态风险因子对清水江悬浮物进行了汞污染评价以及汞残留指数对清水江鱼体汞进行了污染评价。结果表明,清水江旁海段悬浮物汞污染程度高于清水江下司段,并已达到了重度潜在生态危害水平。然而,清水江水和鱼体未受到汞的污染,分析认为磷化工尾矿可能是加剧清水江悬浮物汞污染的原因之一。