有机物中微量砷测定方法的改进

在对有机物中微量砷测定方法综合分析的基础上，选用了砷斑法与Ａｇ－ＤＤＴＣ法相结合的方法检测有机物中的微量砷。重点对Ａｇ－ＤＤＴＣ法的操作内容作了两处改进。实验表明，新方法检测有机物中的微量砷快速，准确。     

有机物中微量砷测定方法改进探讨

本文在对有机物中微量砷测定方法综合分析的基础上，选用了砷斑法与Ａｇ－ＤＤＴＣ法相结合的方法检测有机物中的微量砷，重点对Ａｇ－ＤＤＴＣ法的操作内容作了两处改进，并做了对比实验，实验表明，本文设计的砷斑法与Ａｇ－ＤＤＴＣ法相结合的方法检测有机物中的微量砷是一种快速，准确的分析方法，目前，在我国有推广意义。     

电感耦合等离子体发射光谱法测定高纯磷中微量砷

研究了ＩＣＰ－ＡＥＳ法测定高纯磷中的微量砷，实验结果表明，该法回收率为９４．９％～１０１．５％，分析精密度（ｎ＝９）ＲＳＤ％＜２．０％，方法快速、准确度好。     

磷矿石中微量砷测定的新方法

研究测定磷矿石中微量砷的新方法,以硝酸银—乙酸—聚乙烯醇（ＰＶＡ）—乙醇作为砷化氢吸收液,Ｚｎ－ＫＩ－ＳｎＣｌ２为还原体系的新银盐光度法测定砷。Ａｓ３＋质量浓度在０～７．５μｇ／５ｍｌ范围内服从Ｂｅｅｒ定律。方法回收率为９６％～１００．５％,分析含砷１．６０×１０－３％,ＲＳＤ为１．２３％,方法检出限为１．９×１０－６ｇ／Ｌ。     

特纯五硫化二砷的制备

特纯五硫化二砷的制备韩汉民（安徽师范大学芜湖市２４１０００）１前言特纯Ａｓ＿２Ｓ＿５应用于科学技术的许多部门￣［１］，而我国目前市售的Ａｓ＿２Ｓ＿５最高纯度仅为９８．０％￣［２］，因此，特纯Ａｓ＿２Ｓ＿５的制备具有很强的实际意义。Ａｓ＿２Ｓ＿５的制备...     

CALIXE［4］ARENE AS A TEMPLATE FOR CONTROLLING REGIOCHEMISTRY OF PHOTODIMERIZATION OF 9－SUBSTITUTED AN

ＣＡＬＩＸＥ［４］ＡＲＥＮＥＡＳＡＴＥＭＰＬＡＴＥＦＯＲＣＯＮＴＲＯＬＬＩＮＧＲＥＧＩＯＣＨＥＭＩＳＴＲＹＯＦＰＨＯＴＯＤＩＭＥＲＩＺＡＴＩＯＮＯＦ９－ＳＵＢＳＴＩＴＵＴＥＤＡＮＴＨＲＡＣＥＮＥＬＩＹＩ；ＴＯＮＧＺＨＥＮ－ＨＥ（ＣＨＥＮ－ＨＯＴＵＮＧ...     

1－苯基－5－巯基四氮唑对胶态金催化Co（Ⅲ）络合物氧化对苯二胺彩显剂的反应的影响

本文在碱性介质中，研究了ＰＭＴ（１－苯基－５－巯基四氮唑）存在时胶态金催化Ｃｏ（ＮＨ＿３）＿６Ｃｌ＿３氧化对苯二胺彩显剂（ＰＰＤ）的动力学，反应跟踪是通过可见紫外分光光度计监测ＰＰＤ的完全氧化产物，ＱＤＩ的显色反应来进行的。结果表明，在ｐＨ为１０．２０，且胶态金的初始浓度一定时，ＰＭＴ对反应初始速率有较大的影响：ＰＭＴ的初始浓度［ＰＭＴ］。较小时，对反应有抑制作用：而［ＰＭＴ］。较大时，对反应有促进作用。通过在无ＰＭＴ、低［ＰＭＴ］。高［ＰＭＴ］。时对上述反应动力学的测定，我们推测ＰＭＴ对反应的抑制－促进作用是由于ＰＭＴ在胶态金上吸附状态的变化造成的。实验表明，当胶态金的初始浓度一定时，ＰＭＴ对［Ｃｏ（ＮＨ＿３）＿５Ｃｌ］Ｃｌ＿２氧化ＰＰＤ的反应也有类似作用。     

文摘

文摘美国ＣＡ文摘［ＣＡ１１５：３７５０５ｎ］印制板镀铜电解液Ｄｅｚｈａｖａ，Ｔ．Ｉ．（前苏联）．ＳＵ１，６２４，０５９镀液中含硫酸铜２３０～２５０，硫酸３０～５０，焦磷酸钠０．２～０．４及氯化铜０．００５～０．００７ｇ／Ｌ，稳定性良好。［ＣＡ１１５：...     

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文摘ＣＡ文摘［ＣＡ１１５：１９２４４７ｐ］缎状镍或合金电镀Ｍｕｒａｋａｍｉ．Ｔｏｒｕ．日本公开特许，ＪＰ０３３９４９５［９１，３９，４９５］镀液中除阴离子型有机物外，还含水中溶解度１０～４００ｇ／Ｌ（２０℃）的季铵盐阳离子型表面活性剂。［ＣＡ１１５：...     

化妆品中微量铅、砷的极谱连续测定

化妆品中微量铅、砷的极谱连续测定蔡卓，黄孚畅（广西大学化学系南宁５３０００４）化妆品中有害元素铅、砷含量的高低，直接影响消费者的健康，对其进行检测十分必要。目前测定化妆品中微量铅的方法主要有双硫腙比色法和原子吸收光谱法￣［１］。双硫腙比色法所需试剂毒...     

Quality of groundwater in eastern Croatia. The problem of arsenic pollution

Groundwater in the area of eastern Croatia contains high concentrations of iron, manganese, ammonia, organic substances and arsenic. The appearance of inorganic arsenic in groundwater is mainly caused by arsenic from natural geological sources. Since the groundwater is the main source of drinking water for the population in this area, almost 200,000 people are daily drinking water with arsenic concentration ranging from 10 to 610 μg/L. The Croatian legislation recently revised the maximum concentration limit (MCL) for arsenic in drinking water to 10 μg/L. The population in the two towns (Osijek and Vinkovci) of this region is supplied with groundwater processed by coagulation-filtration method, but in the other towns and villages water treatment implies only rapid sand filtration. Both methods for water treatment have resulted with higher arsenic concentration than MCL, so the main goal of this study was determination of population exposure to arsenic via drinking water and possible improvement of drinking water quality. Population exposure to arsenic via drinking water is determined with hair analysis, since the hair arsenic concentration is one of three most commonly employed biomarkers used to identify or quantify overall arsenic exposure. During this study the preliminary analyses of hair arsenic concentrations in several towns and villages in eastern Croatia were provided. The positive correlation between heightened arsenic concentration in drinking water and hair arsenic concentration was determined. In order to improve drinking water quality e.g. arsenic removal from contaminated drinking water, different modified adsorbents were used and compared (zeolite–clinoptilolite, manganese greensand and cationic exchange resin). Adsorbents were chemically modified and saturated with Fe(III) ions, while the arsenic solutions were prepared by processed groundwater.     

Interaction of Mg-enriched kaolinite-bentonite ceramics with arsenic aqueous solutions

Mg-enriched kaolinite-bentonite ceramics prepared in this work exhibited very porous and non-uniform structures, with grain sizes ranging from 1 to 20 µm. During the interaction of this ceramics with aqueous solutions of Na₂HAsO₄·7H₂O, it was observed that the concentrations of Na, K, Ca and Mg in the ceramics and arsenic concentration in the solution decrease. These changes of metals concentrations in the ceramics and arsenic concentrations in water solutions appear to be on the account of arsenic deposition into the ceramics surface. The interaction of the ceramic samples prepared at 600 °C and 800 °C with used arsenic aqueous solutions reduced their arsenic concentration about 70-90%.     

煤矸石中汞、砷的研究进展

煤矿生产过程中伴生的大量煤矸石不仅占用土地资源,而且在露天堆放的过程中其含有的有害微量元素汞、砷等会进入自然环境中,对环境造成严重污染。通过总结,介绍了国内外学者对于煤矸石中汞、砷的研究成果。主要从煤矸石中汞、砷含量,煤矸石加热汞、砷释放,煤矸石中汞、砷淋溶析出以及煤矸石中汞、砷赋存形态四个方面进行总结。以期为更多学者对于煤矸石中汞、砷的研究工作提供一定的帮助。     

负载铁离子活性炭除砷的研究进展

砷污染是一个严重的世界问题,在其诸多的去除方法中,负载铁离子活性炭兼顾了活性炭和混凝沉淀的优势,可高效去除砷离子.作者对负载铁离子活性炭的制备方法、影响砷去除率的主要因素和吸附模型的研究现状进行了详细评述,其中负载铁离子活性炭的孔径结构、表面性质,负载铁离子的形貌、分布、种类和质量等决定着其吸附容量；通过调节搅拌时间、...     

极谱法测定金矿石中的砷

在氢氧化钠-硼砂的底液体系中对金矿石进行极谱测定,在峰电位-0.35 V,砷的质量浓度在2～400μg/mL之间时砷的浓度与峰电流成线性关系。选用含有甘露醇的氢氧化钠硼砂的底液测定砷,精度好,准确度高,检出限为0.002μg/mL。     

原子荧光光谱法测定绵头雪莲花中的痕量砷

采用原子荧光光谱法测定绵头雪莲花中的微量砷,测量结果为0.5994 mg/kg,方法检出限为0.02μg/L,回收率为93%~105%,RSD为0.607%。测量结果表明绵头雪莲花中的砷含量没有超出国家安全标准,而且原子荧光光谱法对于测定绵头雪莲花中的砷含量具有精密度高、操作简单、快速和灵敏度高的优点。     

改性活性炭除砷研究进展

砷一直以来是我国优先控制的污染物,随着现代化的高速发展,水中砷污染问题愈演愈烈。如何高效,环保的去除水中的砷是一个重要的研究方向。相比于传统方法投资费用高,二次污染严重等缺点,日前新兴起的对活性炭进行改性来除砷效果显著。对近些年处理水中砷的方法进行了简单综述,并进行了总结与展望。     

Arsenic interactions during co-combustion processes based on thermodynamic equilibrium calculations

Arsenic emissions are currently considered to be one of foremost importance. Arsenic volatility is higher than most of trace elements, but its vaporization behaviour is strongly dependent on the atmosphere composition. In this sense, thermodynamic equilibrium calculations, using HSC-Chemistry 5.0 software, were performed to evaluate the influence of different compounds in the distribution and mode of occurrence of arsenic in co-combustion processes. The influence of different parameters influencing arsenic behaviour, such as temperature, pressure, trace element concentration and flue gas composition on equilibrium composition were also evaluated. Predicting arsenic species, based on combustion conditions and fuel composition, will be useful to choose the best available control technology to reduce arsenic emissions. Finally, the possible interactions between arsenic and different trace elements (TE), mercury, cadmium and antimony, relevant from an environmental point of view, have also been studied; these interactions are not usually considered in thermodynamic studies; however, TE’s interactions affects the behaviour of a single TE, not only as a result of the formation of new species, but also, because of the different reactivity of TEs towards different elements which may affect TE’s volatilization behaviours. From results obtained in this study it may be concluded that in most cases, arsenic is mainly captured in ashes as a result of the formation of thermally stable species both from interactions with bulk ash and TE’s interactions. Nevertheless, the presence of some compounds (silicon, chlorine and sulphur) may enhance arsenic volatilization.     

An overview of arsenic removal by pressure-drivenmembrane processes

Management of hazardous wastes, such as arsenic, is one of major public concern. Arsenic is a naturally occurring metalloid, which is widely distributed in nature. Recently, arsenic in drinking water attracted attention because some of the drinking water resources contain considerable concentrations of arsenic which cause acute; and chronic symptoms in many countries, especially in Bangladesh, China, Mongolia, and Taiwan. In 2001, the USEPA promulgated a rule lowering the arsenic MCL from 5 μgL⁻¹ to 10 μgL⁻¹. This paper offers an overview of geochemistry, distribution, sources, regulations, acute and chronic symptoms, and applications of membrane technologies in the water treatment research that have already been realized or that are suggested on the basis of bench or lab scale research. These membrane technologies include RO, NF, UF, and MF. Most of theses applications have proven to be reliable in removing arsenic from water. The possible influence of some source water parameters, membrane material, membrane types, membrane processes on arsenic removal efficiency by membrane technologies are also explored. This review paper also offers data relating to regulations of arsenic standard, acute and chronic symptoms that are caused by the exposure of arsenic to explain why water treatments need to use the membrane technology to meet the MCL standard.     

Effect of operating conditions in removal of arsenic from water by nanofiltration membrane

The removal of arsenic from synthetic waters and surface water by nanofiltration (NF) membrane was investigated. In synthetic solutions, arsenic rejection experiments included variation of arsenic retentate concentration, transmembrane pressure, crossflow velocity and temperature. Arsenic rejection increased with arsenic retentate concentration. Arsenic was removed 93-99% from synthetic feed waters containing between 100 and 382 μg/L as V, resulting in permeate arsenic concentrations of about 5 μg/L. Under studied conditions, arsenic rejection was independent of transmembrane pressure, crossflow velocity and temperature. In surface water, the mean rejection of As V was 95% while the rejection of sulfate was 97%. The co-occurrence of dissolved inorganics does not significantly influence arsenic rejection. The mean concentration of As in collected permeated was 8 μg/L. The mean rejection of TDS, total hardness and conductivity were 75, 88 and 75% respectively.