改性海泡石处理水中低质量浓度NO3-的研究

实验制备酸洗及负载纳米零价铁的海泡石,进行改性海泡石吸附及还原水中低质量浓度NO~-_3的实验研究。结果表明,对于酸洗海泡石(PNS)吸附NO~-_3,吸附效果高于天然海泡石,Freundlich模型比Langmuir模型更好地拟合NO~-_3等温吸附曲线,吸附过程为物理吸附非自发过程,吸附为放热反应,温度升高不利于吸附进行;负载纳米零价铁的海泡石(PNS-nZVI)处理水中NO~-_3符合准一级反应动力学模型。在一定范围内,酸性条件下促进NO~-_3的去除,质量浓度越大去除效果越好,温度在30℃时去除率达到峰值,最佳条件下去除率可达到95.4%。PNS-nZVI还原NO~-_3是一个递进过程,初始阶段NO~-_3先转化成中间产物NO~-_2和部分NH~+_4,随着反应进行NO~-_2逐步转化成NH~+_4,NH~+_4在反应产物中所占比重最大。     

Community-Based Integrated Watershed Management

1 INTRODUCTIONIn the past, natural resources management initiatives havefocused on large but specific sector projects such as dams,reservoirs for water supply schemes, irrigation systems,crop production, at forestation, etc. Often these projectswere treated as technical and administrative issues ratherthan as a socio-economic and political one. However, thehigh social and environmental cost of such schemes haveled to a change of paradigm since the 1980s towards small-scale community projec…     

地壳上层金伯利岩中金刚石形成的新资料

<正> 关于金伯利岩中金刚石及超基性岩和榴辉岩捕虏体形成的地幔假说,近几年来几乎已成为定理。对此问题的一些不同的看法,或是因为不值得引起严重注意未被提及,或是因为缺乏足够的论据和实际分析资料而完全被忽视。     

Risk-evaluation of Hi-tech Enterprise in the Process of Approaching Global Market

In the high technology industry, small and medium sized technology enterprises (SMSTEs) play a pivotal role in advancing the whole industry. To achieve sustainable development, they need to extend their scope of business activities beyond a national view and exploit international market actively to meet international competitions that increase quickly in the form of allocating resources within the scope of the world. However, the SMSTEs are also facing risks associated with themselves during the process of exploiting international market owing to their own restrictions, so what they should do is to consider risk evaluations in exploiting the international market.     

家用报警系统DIY实例

当前市场上的各种报警系统种类繁多,各类制造商也是比比皆是,消费者可以随心所欲地选择他们喜欢的系统。各类系统之间的差别也非常有限,下面我们来介绍一套报警设备的DIY方案,供读者参考(由Alicia示范)。     

城市空气中多环芳烃定量测定方法

本文发展了一种对城市空气中多环芳烃(PAH)定量测定的方法。该方法可以用极少量溶剂,相当快地完成测定工作。     

天然水、土壤和岩石中金与腐殖质的相互作用(地球化学和分析综述)

对天然水、土壤和岩石中金与腐殖质相互作用的结果及Au一腐殖酸和AUCL-腐殖酸在体系中相互作用的实验资料进行了研究。研究表明，金与腐殖酸有机质形成配合物的过程，乃是表生带中金的迁移和富集机制的一个重要方面，决定了从联质矿石中萃取金的工艺特点，影响到岩石、矿石、土壤和天然水中金的测定准确性，进而对金矿床普查和评价的效率有决定性的影响。