Effect of membrane surface characteristics on hydraulic flux balance and feed stream translation in concentrate multi-stage system

Concentrate staging which is one of the configurations of reverse osmosis membrane system has made hybridization of different types of membranes such as sea and brackish water reserve osmosis membranes possible. And the essence of hybridization of membranes is to equilibrate permeate and lower energy consumption thereby reducing environmental impact. But the interaction between certain features of concentrate staging and membrane characteristics could influence membrane performance. Thus, this work was designed to investigate the impact of membrane surface characteristic on hydraulic flux balance and feed stream translation along a concentrate multi-stage system. Seawater from South Sea in Changwon city of South Korea and two commercial brackish water membranes; RE4040-FE, and RE4040-BLR with similar surface charge and varying surface roughness were used for the experiment. Experimental results showed that permeate flux and permeate total dissolved solid from the lead to the rear stage increased for RE4040-BLR with average surface roughness of 19.8 nm and decreased for RE4040-FE with average surface roughness of 44.4 nm. And these performances correlated with Mg2+ and total ion counts for RE4040-BLR and RE4040-FE membrane surfaces, respectively.