Electrochemical disinfection of secondary wastewater treatment plant (WWTP) effluent

In this work the electrochemical disinfection of the effluent of a secondary wastewater treatment plant is investigated In the experimental work, performed on-site with real effluents of the WWTP located in Vuelta Ostrera (Cantabria, Spain), boron-doped diamond (BDD) electrodes were employed The initial concentration of E in the effluent of the WWTP varied in the range 1 3 x 10(4)-5 2 x 10(5) cfu/mL The influence of two operation variables on the kinetics of E deactivation was investigated i) The applied current density was varied in the range J - 40-120 mA/cm(2), showing first order kinetics, and linear dependency of the apparent kinetic constant with the applied current density, and ii) the chloride concentration was varied in the range 60-1,050 mg/L, showing that increasing chloride content also enhanced the kinetics of the E coli deactivation The latter parameter is particularly important in coastal areas, as in the case of the present study The formation of disinfection by-products (DBPs) was followed by measuring the content of trihalomethanes (THMs) that nevertheless was maintained below 100 mu g/L, so it can be concluded that the formation of DBPs is not a disadvantage of electrochemical disinfection of secondary effluents of WWTP