International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators
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SM/EB-25
Design of Electron Beam Sludge Hygienization Plant Y.. Kim1, B. Han1, J.K. Kim1, N.B. Yaacov2, and K.Y. Jeong3 1EB TECH CO., LTD., Yongsan-dong Yuseong-gu, Daejeon, Republic of Korea Corresponding Author: cleaner@eb-tech.com Digested sludge from municipal wastewater treatment has long been used directly in agriculture in Israel. However, owing to the infection by pathogenic microorganisms, the sludge must be processed to reduce the number of pathogens. The high energy ionizing radiation has the ability to inactivate the pathogens with a very high degree of reliability and in a clean and efficient manner. The ionizing radiation interacts with matter both directly and indirectly. Direct interaction takes place with critical molecules like DNA and the proteins present in the microorganisms, thus causing cell death. During indirect interaction, radiolysis products of water result in the formation of highly reactive intermediates that then react with the target biomolecules, culminating in cell death.The laboratory scale studies had been carried out regarding the possibility of electron beam application for sludge hygienization. Experimental system with nozzle type sludge feeder and stainless steel belt conveyor was constructed for irradiation under continuous feeding conditions of sludge cakes with electron beam of dose rate of 40 kGy/s. Survival curves of microbial population for total coli-forms, fecal coli-forms, E. coli and Salmonellae sp. in dewatered anaerobic digested sludge cake deceased as a function of radiation absorbed doses. Based on laboratory data, an industrial scale plant with the capacity to treat 7000 m3 of dewatered sludge per month (18% solid contents) with 10 kGy has been planned. This plant will be equipped with an electron accelerator (2.5 MeV, 100 kW) and handling facilities, and is expected to be more economical than other sludge disposal processes, such as incineration, lime stabilization, etc. The utilization of electron beam on sludge will necessitate the development of technologies that can treat the sludge in a reliable, efficient and cost effective manner.
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