Electrochemical disinfection of secondary wastewater treatment plant (WWTP) effluent

摘要

In this work the electrochemical disinfection of the effluent of a secondary wastewaterntreatment plant is investigated. In the experimental work, performed on-site with real effluentsnof the WWTP located in Vuelta Ostrera (Cantabria, Spain), boron-doped diamond (BDD)nelectrodes were employed. The initial concentration of E. coli in the effluent of the WWTP variednin the range 1.3 £ 104n–5.2 £ 105ncfu/mL. The influence of two operation variables on thenkinetics of E. coli deactivation was investigated: i) The applied current density was varied innthe range J ¼ 40–120mA/cm2n, showing first order kinetics, and linear dependency of thenapparent kinetic constant with the applied current density; and ii) the chloride concentrationnwas varied in the range 60–1,050mg/L, showing that increasing chloride content also enhancednthe kinetics of the E. coli deactivation. The latter parameter is particularly important in coastalnareas, as in the case of the present study. The formation of disinfection by-products (DBPs)nwas followed by measuring the content of trihalomethanes (THMs) that nevertheless wasnmaintained below 100mg/L, so it can be concluded that the formation of DBPs is not andisadvantage of electrochemical disinfection of secondary effluents of WWTP.