Combating water shortages with innovative uses of membranes

3. Cost economics A s the membrane costs are dropping globally t o the order of 17%, the overall production cost T he paper discusses threadbare on the ways a nd means to make RO a cost-effective technol ogy by the available alternatives in the pre-treat- Comparison of water quality between UF and coagulation/sand filter in pre-treatment Items Raw water UF permeate Coagulation and SF product Primary SF Polishing SF Turbidity, NTU B efore BW After BW 0.4 0.4 <0.001 <0.001 <0.004 1.0 <0.0015 0.01 SDI, NTU B efore BW After BW 4.5 4.1 1.6 1.5 2.6 5.7 1.6 1.8 pH 8.2 8.15 -- 7.4 m ent. With seawater/surface water availability b eing what it is both quality and quantity wise a pplication o f membranes and advanced pret reatment including MF/UF pre-treatment are u sed so as to be cost effective.