Removal of chlorine and monochloramine from tap water using graphene oxide membranes
Tobias Foller, Xinyue Wen, Yee Yee Khine, Dali Ji, Tarakranjan Gupta, Matthew Muller, Cristina Scret, Rakesh Joshi
Abstract
Residual levels of chlorine and monochloramine (chlor(am-)ine) in water not only cause unpleasant odour and taste but also pose a challenge for chlor(am-)ine sensitive applications polymeric membranes used in reverse osmosis for desalination. Current solution to remove chlor(am-)ine have their limitations and it is thus desirable to develop an alternative technology that can remove chlor(am-)ine in a simple filtration process. In this study, we show that graphene oxide (GO) membranes can be used to remove chlor(am-)ine from tap water. The tested feed chlorine and monochloramine concentrations are up to 50 ppm and 9 ppm respectively. For all tested feed concentrations, the permeate chlor(am-)ine concentration is < 0.1 ppm after passing through GO membranes. We show that both flat sheet and hollow fibre GO membranes filter out chlor(am-)ine over days of continuous operation. Especially our hollow fibre GO membranes offer a great opportunity for easy scalability. Thus our study highlights not only the filtration properties of GO membranes but also its feasibility as an excellent contender for next-generation membrane technology.