| 摘要 |
<p>PROBLEM TO BE SOLVED: To do good filtration even in a start-up period until organism filtration by a method in which in an immersion type membrane element using a nonwoven fabric as a filter body on the surface, the nonwoven fabric to which a gelling agent is adhered is immersed in raw water, the gelling agent is expanded to form a gel layer as the filter body of a small opening. SOLUTION: A membrane element is formed from a rectangular frame body, and nonwoven fabrics are spread on the surface and back of the element. A gelling agent is adhered in advance to the surface of the nonwoven fabric, which is immersed in raw water to expand the gelling agent with water, and a gel layer 3 as a filter body of small opening is formed on the nonwoven fabric. By the action of the gel layer 3, without forming an organism membrane, a high filtration capacity can be demonstrated from start-up. The raw water, after being filtered by being passed through the gel layer 3 and the nonwoven fabrics 1, is passed through a spacer 5 having through holes 4 and retained in the upper part of the element to be discharged as treated water 7 from a water collecting outlet 8.</p> |
