| 摘要 |
PURPOSE:To efficiently perform separating operation by a membrane while peeling the deposit on the membrane surface and to prevent the deterioration of flux by forming a porous layer wherein fine particles are bonded by a microorganism-decomposable binder on the membrane face of a raw liquid side of the permeation membrane. CONSTITUTION:A binder such as chitosan decomposed by microorganism is dissolved in water or a solvent such as an organic solvent and fine particles such as iron oxide are mixed with this soln. and this mixture is circulated on a permeation membrane and a porous layer is formed by permeating one part of the solvent. Raw liquid 3 is fed under pressurization to the porous layer 2 side of the permeation membrane 1 formed with the porous layer 2 by this method and allowed to flow parallel to the membrane face at high velocity and circulated to obtain permeated liquid 4. In case of continuing the separating operation by the membrane, a gel layer 5 is formed on the surface of the porous layer 2 but dependent nutritive bacteria incorporated therein slowly decompose the binder bonding the fine particles of the porous layer 2 and the fine particles weakened with bound water are peeled by the flow of circulated water and the gel layer 5 is peeled and the deterioration of flux is inhibited.
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