冷原子荧光光谱法测定城市污水中总汞

采用冷原子荧光光谱法测定城市污水中总汞。实验结果表明,线性关系良好（在标准曲线0．00～1．60μg／L内,平均相关系数γ为0．9992以上）,精密度较好（相对标准偏差为0．68％1．57％）,准确度、灵敏度较高（加标回收率为98．0％-104．0％,最低检出限为0．02μg／L）,是测定城市污水中总汞的较好方法。     

原子荧光光谱法测定水处理剂聚氯化铝中砷

采用原子荧光光谱法测定水处理剂聚氯化铝中砷。实验结果表明,线性关系良好（在标准曲线0．0～30．0μg／L内,平均相关系数Y为0．9996）,精密度较好（相对标准偏差为1．76％～2．66％）,准确度、灵敏度较高（加标回收率为103．5％～107．7％,最低检出限为0．08μg／L）,是测定水处理剂聚氯化铝中砷的较好方法。     

原子荧光光谱法测定聚合氯化铝中汞

本文应用原子荧光光谱法测定了自来水厂用液体和固体净水剂-聚合氯化铝中汞的含量。对试样的预处理和仪器的工作条件作了评述,还对各种对测定有影响的因素做了研究并予以优化选择。方法的检出限为0．0015μg／g,在对7种聚合氯化铝的实样进行分析的基础上作了回收率试验,所得结果为87．1％-100．9％。     

原子荧光光谱法测定锡精矿中汞

建立了原子荧光光谱法测定锡精矿中汞的分析方法。试样经王水(1+1)溶解,以盐酸(5%)为载流,氯化亚锡(200g/L)溶液为还原剂,用原子荧光光谱法测定样品中的汞。考察了测定的最佳条件、锡及共存元素对测定的影响。方法相对标准偏差为5.9%~6.3%,与冷原子吸收光谱法对比结果令人满意。方法的准确度和精密度均能满足分析需要,具有较强的实用性。     

双道原子荧光光谱法测定土壤中汞

采用沸水浴消解,用硝酸(3+1)对土壤中样品进行前处理,并用硼氢化钾(0.5g/L)作还原剂,硝酸(1%)作载液进行测定,建立了双道原子荧光光谱法测定土壤中汞的方法。对灯电流、负高压等参数进行优化。结果表明:经多个土壤成分分析标准物质验证,方法的检出限为0.000 7mg/kg,相对标准偏差为3.9%,加标回收率为95.4%~101%,方法简单、准确度高,适合于土壤中微量汞的测定。     

氯化亚锡还原-原子荧光光谱法测定银精矿中汞

建立了原子荧光光谱法测定银精矿中汞的分析方法。试样经盐酸、硝酸溶解,在盐酸介质中,以盐酸(5%)为载流,氯化亚锡(200g/L)溶液为还原剂,用原子荧光光谱法测定银精矿样品中汞的含量。对仪器的最佳工作条件、还原剂的种类和浓度、样品溶样方式、共存元素的干扰等各方面进行了详细研究。结果表明,方法的相对标准偏差为3.1%~9.1%,与冷原子吸收光谱法测定结果相吻合。方法的准确度和精密度均能满足银精矿样品的检测需求,值得推广使用。     

原子荧光光谱法测定水中痕量汞

汞污染主要来自汞矿开采、冶炼、燃煤和化工工业等方面。汞一旦进入水源水体，对人体的危害便会涉及到中枢神经系统、消化系统及肾脏，此外对呼吸系统、皮肤、血液及眼睛也有一定的影响。《城市供水水质标准》规定饮用水中汞的限值为0．001mg／L。氢化物发生原子荧光光谱法是测定水中痕量汞的重要方法。     

原子荧光法测定聚氯化铝中的砷

建立了原子荧光法测定聚氯化铝中的砷的方法。结果表明,该方法线性关系良好,质量浓度为0～10．0μg／L时,平均相关系数r为0．9996,相对标准偏差为0．78％～1．03％,加标回收率为97．9％～101．7％,最低检出限为0．0140μg/L。该方法有较好的精密度、准确度和灵敏度,适用于测定水处理剂聚氯化铝中的砷。     

多道全自动原子荧光光谱法测定土壤中的砷和汞

采用湿法消解对不同地区不同深度的土壤进行前处理,在最佳的实验条件下,应用原子荧光光谱法测定砷和汞的含量,测定的相对标准偏差As为1.4%².3%,Hg为2.0%2.3%,Hg为2.0%³.5%,加标回收率As为91%3.5%,加标回收率As为91%¹06%,Hg为96%106%,Hg为96%¹02%。方法操作简单、快速,检出限、准确度均能满足土壤环境样品检验的要求。     

原子荧光光谱法在测定硫磺微量元素汞中的应用

采用原子荧光光谱法测定硫磺中微量元素汞。利用正交试验法研究了硝酸-双氧水密闭消化硫磺样品的溶解条件,确定了仪器最佳测试条件,探讨了硝酸介质、硼氢化钾浓度对测定结果的影响。在选定的仪器条件下,对食品级硫磺和工业级硫磺两种样品中的汞进行了测定,方法的检出限为0.0127ng/m L,回收率为98.0%~104.0%,精密度为2.00%~4.74%(n=11)。建立的方法具有灵敏度高、简便、结果准确、无环境污染的特点。本文对原子荧光光谱法测定硫磺中微量元素汞的应用进行了方法总结和研究,具有较大的实用和借鉴意义。     

氢化物原子荧光法测定聚合氯化铝中汞的含量

探讨了应用原子荧光光度计测定聚合氯化铝中汞含量的技术和方法,测定方法以10%盐酸为介质,15g/L硼氢化钠为还原剂。实验得到,该方法线性范围为0～10.0μg/L,相关系数r=0.9996,检出限为0.054μg/L,相对标准偏差为1.78%,回收率为94.6%～103.7%。实验结果表明,该方法精密度好,回收率高,操作简单,可用于测定聚合氯化铝中汞的含量。     

原子荧光法测定饮用水中痕量铅

采用原子荧光法测定生活饮用水中铅的含量。试验结果表明，该方法的回归方程为y=37．00x＋28．25，r=0．999，在0．001～0．025mg／L范围内有良好的线性关系。采用该方法测定水中痕量铅能获得理想的结果，可在生活饮用水检测中推广运用。     

原子荧光光谱测定水中锑的结果不确定度评定

采用直观的因果图,对原子荧光光谱法测定水中锑含量的结果不确定度来源及其对测量不确定度的影响进行了分析.建立了有效的数学模型,利用相对标准不确定度分步计算及整体合成进行测量不确定度的评定,并在锑含量为1.2μg/L的水样测定中,获得其相对标准不确定度为3.6%.     

Cellular proteins of Microcystis aeruginosa inhibiting coagulation with polyaluminum chloride

Cyanobacterial growth in semi-closed water areas such as reservoirs brings about a coagulation inhibition in a drinking water treatment system, but the inhibitory substances and mechanisms involved have yet to be elucidated. In this study, proteins having a high affinity with polyaluminum chloride (PACl) were isolated from organic substances produced by Microcystis aeruginosa with the affinity chromatography technique. Both extracellular organic matter (EOM) and cellular organic matter (COM) disturbed the flocculation of suspended kaolin with PACl, but it was likely that nonproteinous substances in EOM cause the reduction of coagulation effciency. In contrast, proteins in COM were obtained as possible inhibitory substances for the coagulation with PACl. These proteins could consume PACl in the coagulation process due to the formation of chelate complexes between these inhibitory proteins and the coagulant. The consumption of PACl by cyanobacterial proteins could be one of the important causes of the increase in coagulant demand.     

铝灰一步酸溶法制备聚合氯化铝的试验研究

以铝灰为原料,用一步酸溶法制备聚合氯化铝.对铝灰、盐酸、水三者的配比以及反应温度、反应时间、熟化温度、熟化时间、搅拌速度等参数对聚合氯化铝的性能影响进行了试验研究,确定了制备聚合氯化铝的最佳工艺条件.产品的各项指标达到了国家相关标准.     

Mechanism of natural organic matter removal by polyaluminum chloride: effect of coagulant particle size and hydrolysis kinetics

The mechanism of natural organic matter (NOM) removal by AlCl(3) and polyaluminum chloride (PACl) was investigated through bench-scale tests. The fraction distributions of NOM and residual Al after coagulation in solution, colloid and sediment were analyzed as changes of coagulant dosage and pH. The influence of NOM, coagulant dose and pH on coagulation kinetics of AlCl(3) was investigated using photometric dispersion analyzer compared with PACl. Monomeric Al species (Al(a)) shows high ability to satisfy some unsaturated coordinate bonds of NOM to facilitate particle and NOM removal, while most of the flocs formed by Al(a) are small and difficult to settle. Medium polymerized Al species (Al(b)) can destabilize particle and NOM efficiently, while some flocs formed by Al(b) are not large and not easy to precipitate as compared to those formed by colloidal or solid Al species (Al(c)). Thus, Al(c) could adsorb and remove NOM efficiently. The removal of contaminant by species of Al(a), Al(b) and Al(c) follows mechanisms of complexation, neutralization and adsorption, respectively. Unlike preformed Al(b) in PACl, in-situ-formed Al(b) can remove NOM and particle more efficiently via the mechanism of further hydrolysis and transfer into Al(c) during coagulation. While the presence of NOM would reduce Al(b) formed in-situ due to the complexation of NOM and Al(a).     

Floc morphology and cyclic shearing recovery: comparison of alum and polyaluminum chloride coagulants

This study investigated the floc formation and re-aggregation potential for alum, polyaluminum chloride (PACl) and a blend of these coagulants. Bench-scale testing included floc morphology characterization for well-developed floc, post-shear floc, and non-settleable (filter influent) floc. Different applications of coagulants were observed to produce non-settleable floc that was morphologically different. The alum treatment had a decrease in average floc size from coagulated to non-settleable conditions, whereas the PACl and PACl/alum treatments resulted in similar sized floc between these processes. Zeta potential distribution measurements showed that the alum treatment resulted in a negative shift from coagulated to non-settleable conditions whereas the PACl and PACl/alum treatments had no significant shift. A photometric dispersion analyzer (PDA) was employed to compare the differences between coagulant treatments with respect to shear induced aggregate breakup and recovery. The PDA allowed a dynamic monitoring of initial floc aggregation and measured the degree of recovery from cyclic shearing. The degree of recovery from shearing was greatest for the PACl/alum treatment likely as a result of increased collision efficiency due to more effective charge neutralization.