Abstract
Membrane filtration is a promising water treatment technique, but its high energy consumption hinders its universal application. We herein introduce a low energy consumption filtration system, in which the cobalt rejection rate is greatly enhanced through Donnan exclusion from 10% to 95%. This is achieved by grafting citric acid onto the cellulose filter paper through esterification. The incorporated acid sites exhibits high cobalt affinity which enhances the Donnan exclusion effect. Most importantly, the filtration was conducted at atmospheric pressure yet still achieving permeate flux of 100 L/m2h. In conclusion, we demonstrate a new low energy consumption filtration system with high cobalt rejection through Donnan exclusion effect, which may have promising potential in various heavy metal contaminated waters.