The permeate fluxes decreased slowly until the VRF valuewas
reached to 1.5–2,then remained almost constant for higher VRF values. The slow decrease in fluxes followed by an almost constant for
higher VRF values is probably caused by the initial fast adsorption of
organic matters onto the membrane surface and/or into the membrane pores.The flux decline analysis and contact angles of fouled
membranes for different transmembrane pressures are presented
in Table 8.