High Flux PBI Reverse Osmosis Membranes for Desalination and Water Reuse.

摘要

High flux,high rejection flat polybenzimidazole (PBI) reverse osmosis membranes were prepared. Membrane film casting and processing parameters were first identified and optimized in small-scale laboratory film casting trials. On the basis of these results,membranes measuring 12in. by 36in. and 2.5mils in thickness were prepared and evaluated in long-term testing at 600psi and 400psi with non-chlorinated and chlorinated salt solutions. Two prototype spiral wound modules were fabricated for demonstration purposes. Membrane samples were tested in high pressure test cells against 5000ppm salt solutions. In long-term testing, a decline in flux was observed,presumably the result of pressure induced compaction. Salt rejection remained high or improved slightly with time. In long-term testing against salt solutions containing 10ppm chlorine,reduced water flux was observed after 1000hours. Salt rejection remained well over 90%. The flux decline was attributed,in part,to membrane fouling and compaction.