Organo Corporation

Masaki Miyake

Yoshiaki Hasebe

Masahiro Eguchi

Shohei Yamamoto

Taichi Yamamoto

Hironori Yui

Hizuru Wakayama

Hatsuhiro Matsuda

Masaaki Tomita

Aki Hamamoto

The water treatment method is for treating water to be treated that contains organic matter and a nitrogen component, and includes, in a biological treatment device including at least an aerobic tank: a biological treating for biologically treating inflowing water to be treated aerobically by using sludge that contains granules; a solid-liquid separating for separating the biological treatment solution in the aerobic tank into treated water and concentrated sludge using a solid-liquid separation device; and a sludge returning for returning the concentrated sludge obtained in the solid-liquid separating to a stage before the biological treatment device. The concentration of ammonium nitrogen remaining due to the nitrification reaction in the aerobic tank is measured with an ammonium nitrogen concentration measurement device, and the amount of gas containing oxygen dispersed to the aerobic tank is controlled with a blower so that the measured ammonium nitrogen concentration is within a prescribed range.

Water treatment method and water treatment device

A water treatment method that uses a reaction tank and involves repeatedly performing an operation cycle including: an inflow step for causing an inflow of waste water; a biological treatment step for subjecting the waste water to biological treatment using biological sludge; a sedimentation step for causing the biological sludge to settle; and a drainage step for draining biologically-treated water that has undergone the aforementioned biological treatment. The reaction tank is provided with an inflow port that is disposed at a position lower than an interface position of a biological sludge bed formed at the bottom of the reaction tank in the sedimentation step, and an inflow pipe that extends upward in the vertical direction from the inflow port. In the inflow step, the waste water is caused to gravitationally flow down in the inflow pipe so as to be fed into the biological sludge bed from the inflow port.

Provided are a water treatment method and a water treatment device wherein in a biological treatment of ammonium nitrogen-containing water to be treated, the water to be treated can be treated stably at a high treatment speed even when the nitrogen concentration of the water to be treated is high. This water treatment device biologically treats ammonium nitrogen-containing water to be treated. The water treatment device (water treatment method) is provided with: a nitrification device (nitrification step) for oxidizing ammonium nitrogen to nitrite or nitrate nitrogen using nitrifying bacteria including autotrophic ammonia-oxidizing bacteria and nitrite-oxidizing bacteria contained in microbial activated sludge; and a nitrification rate control means which maintains a molybdenum compound in the nitrification device in such a manner as to control the molybdenum concentration of the water to be treated to 0.025 mg Mo/gN or more, and controls the nitrification rate for the sludge to 0.11 [kgN/(kgVSS&#xb7;day)].

Provided are: a water treatment method that includes at least a denitrification step for denitrifying water to be treated with a denitrifying bacterium in the presence of a hydrogen donor, wherein the denitrification activity of the denitrifying bacterium can be maintained at a high level and thus the treatment speed can be increased; and a water treatment apparatus. The water treatment method includes at least a denitrification step for passing water to be treated through a biological treatment tank and denitrifying the same with a heterotrophic denitrifying bacterium in the presence of a hydrogen donor, wherein: molybdenum is added to the water to be treated to give a concentration of 0.01-1.0 mgMo/gN; a carrier is added to the biological treatment tank; and the nitrogen load to the carrier is controlled to 1.6 kgN/(m-carrier&#xb7;d) or greater.

Water treatment method and water treatment apparatus

Provided is a method for forming aerobic granules in which a semibatch reactor for forming granules is used, the method involving repeatedly carrying out an inflowing step for causing organic-matter-containing wastewater that includes organic matter to flow in, a biological treatment step for biologically treating substances to be treated in the organic-matter-containing drainage water by using microbial sludge, a settling step for allowing the microbial sludge to settle out, and a discharge step for discharging biologically treated water which has been biologically treated, wherein the reaction time is adjusted such that the value obtained by dividing the total cycle time by the reaction time and multiplying the resulting quotient by the ratio of the MLSS concentration to the BOD load charged into the semibatch reactor is within a range of 0.05 to 0.25 kgBOD/kgMLSS/d, and the sludge is drawn such that the sludge retention period is 5 to 25 days.

Method for forming aerobic granules, device for forming aerobic granules, method for treating wastewater, and device for treating wastewater

A granule-forming method using a semi-batch reaction tank, wherein: operation cycles of a first operation cycle for performing a biological treatment step at a first sludge load and after the first operation cycle, a second operation cycle for performing the biological treatment step at a second sludge load are performed repeatedly; the first sludge load is set so that the soluble BOD concentration in the semi-batch reaction tank at the time of completion of the biological treatment step of the first operation cycle does not decrease to a threshold value or less; and the second sludge load is set so that the soluble BOD concentration in the semi-batch reaction tank at the time of completion of the biological treatment step of the second operation cycle is at or below the threshold value.

Growing community of inventors

Tokyo, Japan

Masaki Miyake