Design of Electron Beam Sludge Hygienization Plant

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 40kGy/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 7,000 m of dewatered sludge per month (18% solid contents) with 10 kGy has been planned. This plant will be equipped with an electron accelerator (2.5MeV, 100kW) 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.