放射性废水的膜处理技术研究进展

核燃料的生产、核电厂的运行、同位素的生产和使用等过程都会产生着大量的放射性废水,为了保护环境和人类健康,这些废水必须经过安全、经济和有效的处理处置.放射性废水传统的处理方法主要包括过滤法、离子交换法、蒸发法或这几种工艺的组合.近年来,膜分离技术在放射性废水处理中得到了广泛的研究,发达国家已有应用膜分离技术处理放射性废水的实例,而我国规模化应用的实例还很少见.本文首先介绍了放射性废水的来源及组成,分析了各种放射性废水处理方法的优势和不足,包括化学沉淀法、过滤法、离子交换法、蒸发浓缩法、吸附法、生物还原/吸附法和膜分离法等.在此基础上,重点介绍了各种膜分离技术,包括微滤、超滤、纳滤、反渗透、膜蒸馏等在放射性废水处理中研究与应用现状,对已有的文献资料进行了较系统全面的分析、归纳和总结,对各种方法的优缺点及适用范围进行了比较,对膜技术在放射性废水处理中的应用前景及问题进行了讨论.最后,简要介绍了放射性废水处理产生的浓缩产物的最终处理处置,对放射性废水处理技术未来的研究和发展方向给出了建议.

Research advances in radioactive wastewater treatment using membrane processes

Large amounts of radioactive wastewater are produced during production of nuclear fuel, operation of nuclear power plant, production and application of isotopes and so on. The radioactive wastewater must be treated and disposed safely, economically and efficiently to protect environment and human health. The most commonly used methods for radioactive wastewater treatment include traditional filtration, chemical precipitation, ion exchange and thermal evaporation or combined. In recent years, extensive studies on application of membrane technologies for radioactive wastewater treatment have been carried out because of their advantages such as higher efficiency, lower operational cost and less secondary wastes comparing with traditional methods. There are many industrial application examples of membrane technologies used for practical radioactive wastewater treatment in developed countries, but few in China. In this paper, we firstly introduced the sources and compositions of radioactive wastewater and analyzed the advantages and disadvantages of different traditional treatment methods, including chemical precipitation, traditional filtration, ion exchange, thermal evaporation, adsorption, and biological reduction/biosorption. Afterwards, various types of membrane technologies, such as microfiltration, ultrafiltration, nanofiltration, reverse osmosis and membrane distillation were introduced, and their principles, current status of research and application in the field of radioactive wastewater treatment were systematically analyzed, categorized and summarized based on the large amount of published literatures. The pros and cons and applicability of each membrane technology were compared, and the application potential and possible problems of their future application were discussed. Finally, the final treatment and disposal of concentrated wastes from radioactive wastewater treatment was introduced, and the future direction of research and development of radioactive wastewater treatment was proposed.