| abstract |
A washing method for a separation membrane modulenwhich comprises adding a gel particle equivalent to 3 ton40 % of the internal capacity of a membrane module into anliquid being treated and suspending it therein, removingnand washing built-up materials on the membrane throughncontacting the gel particle to the membrane and theninternal surface of the module, thereby resulting innpreventing the membrane from being obstructed andnincreasing the permeation pressure thereof. The gelnparticle comprises an organic polymeric compound , whichnis gelled by absorbing water, with a specific gravity innwater from 0.9 to 1.25, a volume swelling ratio in waternfrom 150 % to 4000% and a compressive yield stress innwater from 2.0 MPa to 10.0 MPa thereof. n As the gel particle, a thermoplastic polyethylene glycolngel, a thermoplastic polyurethane gel and the like arenillustrated. The gel particle is manufactured by a meltnextrusion molding method. |