Water treatment and disinfection by natural solar radiation in ferrous-persulfate system
A task of simultaneous treatment and disinfection of natural water and municipal wastewater effluents using solar-induced advanced oxidation processes was considered in this study. Using herbicide atrazine and Escherichia coli, the kinetics of both separate and simultaneous processes of destruction and inactivation in different aqueous matrices (deionized water - DW, natural water - NW and treated wastewater - TWW) were studied in the ferrous-persutfate system, activated with natural solar radiation {Sotar/Fe<sup>2+</sup>/S<sub>2</sub>O<sub>8</sub><sup>2-</sup>}. It was found, that the presence of bacterial cells inhibited the rate of atrazine destruction in all matrices, decreasing the rate constants by one order of magnitude. The accumulated sotar doses (Q<sub>UVA</sub>) for 90% atrazine removal in DW, NW and TWW were 5,2, 5,7 and 9,2 kJ/L, respectively. In contrast, the presence of atrazine in NW and TWW did not affect negatively on the E. coli inactivation rates. Inactivation of 95% cells was achieved (~1.5 Log reduction) at doses Q<sub>uva</sub> of 4-6 kJ/L, that is comparable with the Literature data on E. coli inactivation in other oxidation systems. The combined method of simultaneous destruction of micropollutants and inactivation of microbial pathogens has been proposed by using natural solar radiation in the ferrous-persutfate system {Sotar/Fe<sup>2+</sup>/S<sub>2</sub>O<sub>8</sub><sup>2-</sup>}.