Radiation treatment of polluted water and wastewater

Strategies to tackle environmental pollution have been receiving increasing attention throughout the world in recent years. Radiation processing using electron beam accelerators and gamma irradiators has shown very promising results in this area. Radiation processing in wastewater treatment is an additive-free process that uses the short lived reactive species formed during the radiolysis of water for efficient decomposition of pollutants therein. The rapid growth of the global population, together with the increased development of agriculture and industry, have led to the generation of large quantities of polluted industrial and municipal wastewater. The recognition that these polluted waters may pose a serious threat to humans has led technologists to look for cost effective technologies for their treatment. A variety of methods based on biological, chemical, photochemical and electrochemical processes are being explored for decomposing the chemical and biological contaminants present in the wastewaters. Studies in recent years have demonstrated the effectiveness of ionizing radiation such as, gamma rays and electron beams or in combination with other treatments, in the decomposition of refractory organic compounds in aqueous solutions and in the effective removal or inactivation of various microorganisms and parasites. The application of electron beam processing for drinking water, wastewater and groundwater treatment offers the promise of a cost effective process. The installation of the first full scale electron beam plant in Daegu, Republic of Korea, to treat 10 000 m3 day-1 textile wastewater has demonstrated that the process is a cost effective technology when compared to conventional treatment. The regular operation of this facility provides operational data on reliability and additional data for a detailed economic evaluation. The IAEA has been supporting activities in this area by organizing advisory group meetings, consultants meetings, symposia and Technical Committee meetings. Following the recommendations of scientists and consultants, the IAEA established a Coordinated Research Project on Remediation of Polluted Waters and Wastewater by Radiation Processing during the years 2002 to 2006, with the aim of establishing optimal treatment methodologies to treat drinking water and wastewater by using ionizing radiation from gamma rays and electron beam accelerators. This publication describes the most important results and achievements of the participating groups during the course of this Coordinated Research Project and will be of value for research groups working in the field of radiation technology for the treatment of aqueous effluents, and will serve as a basis for both pre-feasibility study and technology implementation