The application of ionising radiation in industrial wastewater treatment technology

An attempt was made to apply radiation techniques in the treatment of industrial wastewater from a dairy, brewery and sugar factory. For degradation of pollutants present in the wastewater, the following methods were used: irradiation, irradiation combined with aeration, ozonation, and combined irradiation and ozonation. For all three types of wastewater, the best method among these listed above appeared to be the method of irradiation combined with ozonation. Most degradable was the wastewater produced in sugar factories, and the least biodegradable appeared to be dairy wastewater. Depending on the dose of ozone and radiation, a maximum 60% reduction of COD was obtained. No effect of the wastewater aeration on its degradation by radiation was found. Changes in the content of mineral compounds were observed in none of the cases. The process of biological treatment of wastewater was carried out in a low-loaded, wetted bed. Pretreatment of the wastewater had no significant effect on the improvement of the biological step operation. Some effect was observed only in the case of the wastewater coming from a sugar factory. For medium concentrated wastewater from food industry, it is not economically justified to apply the pretreatment with the use of ionising radiation. (orig.)