Kurita Water Industries Ltd.

Metawater Co., Ltd.

The University of Kitakyushu

Mitsuharu Terashima

Satoshi Shimizu

Mamoru Iwasaki

Hideaki Iino

Tetsuya Yanase

Hidenari Yasui

Natsumi Noiri

An organic wastewater treatment method that includes a raw sludge removal step, a raw sludge concentration step, a biological treatment step, an excess sludge separation step, an excess sludge concentration step, a sludge mixing step, and a methane fermentation treatment step. The treatment method further includes a sterilization step for heating and sterilizing the concentrated excess sludge upstream of the sludge mixing step. At least one among: (1) the temperature to which the concentrated excess sludge is heated during sterilization, (2) the concentration of concentrated raw sludge and/or the concentration of the concentrated excess sludge, and (3) the mixture ratio between the concentrated raw sludge and the concentrated excess sludge is adjusted according to the fluctuation in the amount of raw sludge generated and the amount of the excess sludge generated, and the temperature of the mixed sludge is controlled to a temperature suited for methane fermentation.

Organic wastewater treatment method and organic wastewater treatment device

In a settling tank of the invention, treated water has good quality and whose operation is stable over a long period. A settling tank includes a tank body having a circular-cylindrical shape whose axial direction corresponds to the vertical direction, a distributor provided in a lower part (near the bottom) of the tank body, an outlet provided in a middle part or a part slightly above the middle part of a side face of the tank body, a receiving tank communicating with the tank body via the outlet, a stirring device provided in the tank body, a trough for extracting treated water provided in an upper part of the tank body, a sludge discharge port through which concentrated sludge is extracted from a lower part of the receiving tank, and so forth. A stirring member is provided below the distributor.

Settling tank and method of operating the same

In a water treatment method and an apparatus therefor, after an anionic polymer flocculant is added to water to be treated, granulation is performed by stirring, and solid-liquid separation is then performed to obtain treated water, and flocs which are not disintegrated by a shearing force during stirring and have a preferable settling property can be formed, so that the quality of treated water is also improved. Particularly, a water treatment method includes a flocculating step of adding an anionic polymer flocculant to water to be treated to form flocculated flocs, a subsequent granulating step of stirring the water to be treated to granulate the flocculated flocs, and a solid-liquid separation step of performing solid-liquid separation of generated granulated substances, wherein a cationic polymer flocculant having a cationic group rate of 10 to 50 mole % is added to the water to be treated before the anionic polymer flocculant is added.

Water treatment method and apparatus therefor

Provided is a desalting device which includes a tower body and a bulge portion bulging downward therefrom, and which prevents uneven flow and causes no dead space within the tower body. The desalting device includes a tower body having a bulge portionbulging downward at a bottom portion thereof, an ion-exchange resin packed in the tower body, and a plurality of strainersfor collecting water being arranged within the bulge portion. The strainers are arranged only in a central region of an inside of the bulge portion excluding an outer peripheral portion of the bulge portion.

Growing community of inventors

Kitakyushu, Japan

Mitsuharu Terashima