31 Effect of coagulation of fouling rate and cleanability of ultrafiltratin membranes

摘要

membrane filtration process has recently received moreand more importance in waste water treatment applications, such as volume reduction ofaqueous wastes, recovery of prectious chemicals from liquid industrial wastes, and purification of drinking water.~(1-3) Among the membrane filtration techniques, continuous cross-flow ultrafiltration (UF) is an innovative method to separate solid/liquid or liguid/liquid phases at a lower pressure of 5-150 psi compared toreverse osmosis (RO) in which the applied pressure is an order of magnitude higher.~4 The application of UF to the removal of oil contaminants from oily wastewater streams has been extensively studied in theoretical aspects.~(5-8) The practical use of UF technology has been reported also in various circumstances.~(e.g., 2, 9, 10) Recently, attempts have been made to combine processes of UF and other treatments for many applications. atters et al. (1987) demonstrated the combination of emulsion solvent extraction and UF to remove toluene~1. Adhan et al. (1991) used a bench-scale UF and powdered activated carbon to remove organic contaminants from groundwater.~(12) UF has also been reported to be combined with the emulsified ion exchangers and surfactants for the metal ion removal from aqueous solutions.~(13, 14) However, there is very little knowledge about the filtration process which combined coagulation and UF, and very few attempts have been made to apply coagulated UF to the treatment of fuel oil contaminated water.