纳米零价铁的制备、改性及对废水中重金属和 有机污染物的去除

纳米零价铁（nZVI）结合了零价铁还原性强和纳米材料比表面积大的特点,能够高效去除水体中的重金属和有机污染物,是当前环境科学领域研究的热点之一。研究表明单一nZVI颗粒存在易团聚及表面易被氧化等问题,影响nZVI颗粒形态和对污染物去除效果,限制了其在环境修复中的应用。针对目前的研究现状,本文分析并总结了以下内容：①nZVI常用的制备方法;②提高nZVI活性与稳定性的改性方法,如合成时添加表面活性剂和负载材料;③nZVI去除废水中Cr、Cd、Cu和As等重金属和硝基苯、氯代芳烃、氯代脂肪烃等有机污染物的主要机理及影响因素;④应用于自然环境中的nZVI可能对环境产生的毒理学效应和在环境修复过程中存在的潜在风险及其评估;⑤对nZVI今后的研究重点和方向进行分析和展望。     

Thermophysical,environmental, and compatibility properties of nitrate and nitrite containing molten salts for medium temperature CSP applications: A critical review

The production of electric energy from solar radiation is nowadays one of the most investigated and developed “carbon free” technology. A throughout investigation of the ceramics most commonly used as heat transfer fluids and/or heat storage materials for concentrating solar power systems (i.e. alkaline and heart alkaline nitrate/nitrite mixtures) is here reported. The study stems by the need to base materials selection on an accurate and critical knowledge of all their characteristics, including their thermophysical, environmental compatibility, and economic features.At this purpose, a rating criterion have been established, to readily show the advantages and disadvantages of each material, and to highlight which characteristics of the examined materials need to be further investigated and improved. Nitrate/nitrite mixtures have also been compared with other ceramics used for thermal storage, such as solid fillers, liquid metals, other salt mixtures, or phase change materials.