Metawater Co., Ltd.

Hideki Kozono

Motoharu Noguchi

Shigehiro Suzuki

Michiko Aoki

Nobuhisa Matsushige

A cleaning method of a membrane filtration system in which a plurality of modules including an inlet side region and an outlet side region separated by a filtration membrane are connected in parallel by a common blow header pipe in the inlet side region, the method including backwashing and blowing in which after the backwashing is started, gas is introduced into the plurality of modules through a blow header pipe. The method further includes forming, before the blowing is started, a gas layer across an entire longitudinal direction of the blow header pipe.

Cleaning method of membrane filtration system and membrane filtration system

The process includes operation as follows: putting ozone generated by an ozone generator into raw water, in a normal mode, to subject the raw water to ozone treatment; injecting a flocculant into the raw water before or after the ozone treatment; filtering the raw water by a separation membrane after the ozone treatment and the injection of the flocculant; and intermittently setting cleaning mode to put a larger quantity of cleaning ozone than that in the normal mode into the raw water so as to intermittently increase the concentration of dissolved ozone, thereby cleaning the filtration membrane.

Process for producing reclaimed water and system for producing reclaimed water

A method of wastewater reutilization by which reusable water can be stably obtained from a wastewater. Ozone is added to a wastewater, such as water resulting from sewage treatment, in such a small amount as to result in a residual ozone concentration as measured before membrane filtration of 0.01-1.0 mg/L. Ozone is thus brought into contact with fine solids contained in the wastewater to alter the surface properties of the fine solids so that the solids are easily to coagulate. Thereafter, a coagulant, e.g., PACl, is added from a coagulant addition device (). The fine solids are coagulated in a coagulation tank () or a line mixer and the resultant water is subjected to membrane filtration with an ozone-resistant separation membrane () such as ceramic membrane. Thus, reusable water is obtained which has a residual ozone concentration, as measured after filtration through the membrane, less than 0.5 mg/L.

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Tokyo, Japan

Hideki Kozono