Sunlight Photooxidation of Organic Pollutants in Wastewater

Abstract

The material presented represents results of a research on a new method for using solar energy for municipal and industrial wastewater treatment. This research seeks to develop economical methods of disinfection and detoxification of wastewaters which would result in the reuse of effluents for crop irrigation. Aerated effluents containing dye-sensitizers were exposed to solar irradiation for various periods of time. The influence of the solar energy, absorbed by these sensitizers in the visible range, on the organic matter and anionic surfactants in secondary effluents was checked by determining the COD and MBAS values of treated wastewater. The disinfection potential of this method was followed by bacteriological analyses of running water or secondary effluents, previously contaminated or enriched, respectively, with laboratory cultures of E. coli, bacteriophages (coliphage X and F2) and polio virus (type L-Sc 1). The influence of this photooxidative method was also studied in eutrophic algae present in the Lake of Galilee. It was found that the conditions under which disinfection proceeds also support algicidal processes, causing lethal damage to algal cultures. Further investigations on stable pesticides (uracil, s-triazine and anilide derivatives) in surface water or industrial wastewater showed that such a method can also be used for detoxifying pesticides in these waters.