Removal of Arsenic from Water with Non-Thermal Plasma (NTP), Coagulation and Membrane Filtration

Abstract

Arsenic in drinking water resources and, especially, in groundwater, represents a severe health problem for millions of people in affected regions. This paper investigates a removal technology combining non-thermal plasma at a reaction time of 30 min, which has improved the downstream coagulation and the filtration efficiency. The results show removal rates of total arsenic over 98%. In addition, WHO limits of less than 10 μ g L − 1 could be achieved in both batch and continuous set-ups. A difference in effective over potential of the NTP reaction of 32 m V over a reaction using air as oxidant was calculated. Kinetic data of arsenic concentrations over time fitted a pseudo first-order reaction. The proposed process combination has shown to be a simple and energy-saving alternative compared to conventional oxidation and adsorption technologies by exploiting the ’enhancer’ effect of ozone and other reactive oxygen species within the NTP.