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随着矿床品位的降低,有色金属冶炼产生的含砷废水排放量逐渐增加。由于砷化物具有剧毒性,大量排放的含砷废液对人体健康产生巨大威胁。随着生活质量的提高,人们对含砷废水的排放要求也越发严格。因此,如何绿色、高效地脱除水体中的砷,是目前研究的重点。介绍了水体中砷的来源与危害,对国内外处理含砷液体的主要脱除技术进行归纳总结。水体脱砷技术按照脱除方式可分为化学法、物理法及微生物法。阐述了各种脱砷技术的基本原理,对不同脱砷技术的适用性及其优缺点进行分析,指出限制这些工艺在工业中应用的主要因素。同时,对化学法与物理法等结合工艺的前景进行了展望,以期为未来脱砷技术的发展提供一定参考。 相似文献
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随着食品、医药及电子行业的不断发展,磷酸及磷酸盐的市场需求量不断增大,并且对磷酸的品质要求也越来越高,尤其是对湿法磷酸中砷杂质的要求,湿法磷酸中砷的含量将直接影响其在磷精细化工领域的应用,因此湿法磷酸中砷的高效、安全去除是亟待解决的一大难题。本文主要对湿法净化磷酸脱砷技术的研究情况进行综述,比较了几种湿法净化磷酸脱砷工艺的优缺点,介绍了较常见的化学沉淀法、结晶法,以及新兴的电沉积法、垂直区域熔融法和微反应器脱砷工艺的应用前景,并指出这些新兴的脱砷工艺将成为今后湿法磷酸的净化脱砷的发展方向,如能解决将这些脱砷工艺在实际中的问题,将会对磷酸工业的发展提供一个更有力的支持。 相似文献
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微量砷的测定有砷斑法、比色法、原子吸收法和溶出伏安法等。试剂盐酸中砷的测定目前主要采用砷斑法,只能获得半定量的结果。王曙等人用苯萃取分离三价砷后,用玻璃碳电极阳极溶出伏安法测定了盐酸中的砷。本文在前人工作的基础上,试验了用圆盘金电极测定砷的合适条件,对As(V)到As(Ⅲ)的还原及各种离子对砷的测定的干扰情况进行了试验。 相似文献
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砷是化妆品中常见的有害重金属之一,长期使用含砷量超标的化妆品将会严重危害人体健康。目前检测化妆品中砷含量的方法主要有砷斑法、银盐法、原子吸收光谱法、原子荧光法、X射线荧光光谱法、电感耦合等离子质谱法。通过介绍化妆品中砷的来源和危害及各种检测方法的原理和特点,期望人们对化妆品中砷的危害及各种检测方法有更全面地认识,能更理性地选择化妆品。 相似文献
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本文综合阐述了第二代半导体材料砷化镓原材料高纯砷的特性,砷储量及分布情况、应用,对比了现有制备技术的优缺点,对影响高纯砷纯度的相关因素进行了分析讨论。目前制备高纯砷的主要技术有升华蒸馏法、铅熔池升华法、砷化氢热分解法、氯化还原法、硫化还原和氧化砷+盐酸还原法等。其中氯化还原法和氧化砷+盐酸还原法是目前工业产量化应用最多的方法。氯化还原法由于其工序冗长,过程中存在氯气等剧毒气体,对设备防腐要求较高,存在安全环保风险;氧化砷+盐酸还原法因其副产物可回收重复利用,工艺流程相对较短,废液、废气和废渣产生更少,对环境更友好。同时讨论了高纯砷粉的制备和杂质的影响及除杂方法。更高纯度、更大规模、更节能、更安全环保、自动化是未来高纯砷的发展方向。 相似文献
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改性粉煤灰处理低浓度含砷含氨氮废水 总被引:1,自引:0,他引:1
在冶金和采矿等行业里,排放废水中的砷和氨氮均存在不同程度的超标。本实验采用粉煤灰对砷和氨氮进行深度处理。考察了不同改性方法对粉煤灰除砷和氨氮的处理效果。实验结果表明: NaOH+FeCl3复合改性的粉煤灰对两种污染物都有较好的去除效果,废水中含砷2 mg/L,含氨氮50 mg/L,复合改性粉煤灰的投加量为20 g/L,废水pH为6,搅拌1 h,砷和氨氮的去除率分别达到83.33%和82.48%,出水满足《污水综合排放标准》(GB8978-1996)中砷和氨氮的排放要求。 相似文献
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砷形态分析方法及其样品预处理技术研究进展 总被引:1,自引:0,他引:1
环境中砷污染问题已引起社会各界的广泛关注。由于不同形态砷的毒性相差甚远,因此,砷的形态分析对于了解砷化物的生态影响及其在环境中迁移转化规律具有重要意义。而不同形态的砷化物在稳定性上存在差异,故选用适当的预处理技术,以确保样品在分离和富集的过程中砷形态及其组成不发生变化。因此,围绕砷形态分析中各种环境样品(如土壤、沉积物、食品、生物样品、水样等)的预处理技术和分析检测方法展开综述,总结了现代常用的砷形态分析检测方法及与之匹配的适当的环境样品预处理技术,并分析了各种方法的优缺点和适用性。 相似文献
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原子荧光法同时测定砷和硒时,两元素之间会互相干扰测定。该文通过大量试验优化条件参数,调整了硼氢化钾浓度和载流盐酸浓度,总结出砷和硒同时测定的最佳条件,并对该条件下的精密度和准确度进行了评估。结果表明硼氢化钾浓度为3.0%和盐酸浓度为10%的条件下,同时测定砷和硒,操作简便,数据准确可靠。 相似文献
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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. 相似文献
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The effective removal of arsenic compounds from strongly contaminated mining water with a high content of As (about 50 mg/l) and other metals, especially iron (about 5000 mg/l) has been studied. The process ran in two steps. At first, the raw acid mining water containing predominantly Fe2+ ions was partially precipitated with a small amount of an alkaline agent. On a small portion of the precipitated iron (about 30–40%), more then 90% of the arsenic was adsorbed forming a toxic precipitate, which was then stirred under an inert agent (Ar) and further in air for 1 h. Secondly, the precipitation of the first step liquid residue (using the same or a different alkaline agent) enabled the final treatment of the mining water at pH 8.5. While arsenic was substantially removed by the first precipitation, the other components including residual iron, manganese, zinc and sulfates were precipitated quantitatively during the second step. The mass of the second precipitate depended strongly on the alkaline agent used in the second step.The mechanism and kinetics of arsenic sorption onto iron species, and phase changes of the sorbent during the sorption process were investigated. The composition of the precipitates was verified by XRD and XRF analyses, as well as by infrared and Raman spectroscopy. The precipitation of a raw mining water resulted in formation of a complex inorganic system where amorphous phases dominated. Various crystalline phases, predominantly concerning Fe(II)–Fe(III), As, Zn and sulfates also appeared, depending on the actual oxidizing state of the whole system and on redistribution of its components.The two-step precipitation of arsenic contaminated mining water results in a significant ecological and economical improvement due to the decrease in the amount of waste toxic mass. 相似文献