Panasonic Intellectual Property Management Co., Ltd.

Yuko Maruo

Daisuke Ino

Masahiro Iseki

Hirofumi Fujita

Yasuhiro Hashimoto

Tomoyasu Takaoka

A method for controlling a liquid treatment apparatus of the present disclosure includes: (i) providing the liquid treatment apparatus; (ii) treating a polluted liquid in a photocatalytic reaction tank by a photocatalytic reaction to produce a treated liquid; (iii) introducing a liquid mixture into a separation tank from the photocatalytic reaction tank through a feed passage by a circulation pump; (iv) introducing a filtrate to an outside of the separation tank through an extraction passage while filtering the liquid mixture introduced into the separation tank by a filtration membrane, and feeding the liquid mixture to the photocatalytic reaction tank through an overflow passage; and (v) making a flow rate of the liquid mixture measured by a liquid mixture flow meter higher than a flow rate of the filtrate measured by a filtrate flow meter by controlling the circulation pump by a controller.

Liquid treatment method and apparatus

Provided is a method for treating a hexavalent chromium-containing aqueous solution by water treatment employing a titanium dioxide photocatalyst that is excellent in both photocatalytic activity and solid-liquid separation performance. The method according to the present disclosure includes the steps of: adding catalyst particles to the aqueous solution; reducing hexavalent chromium by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and stopping the stirring and separating the catalyst particles from the aqueous solution by sedimentation. Each catalyst particle is composed only of a titanium dioxide particle and a zeolite particle, the titanium dioxide particle is adsorbed on the outer surface of the zeolite particle, the zeolite particle has a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.

Method for treating hexavalent chromium-containing aqueous solution

Provided is a method for treating an arsenic-containing aqueous solution by water treatment employing a titanium dioxide photocatalyst that is excellent in both photocatalytic activity and solid-liquid separation performance. The method according to the present disclosure includes the steps: of adding catalyst particles to the aqueous solution; oxidizing trivalent arsenic by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and stopping the stirring and separating the catalyst particles from the aqueous solution by sedimentation. Each catalyst particle is composed only of a titanium dioxide particle and a zeolite particle, the titanium dioxide particle is adsorbed on the outer surface of the zeolite particle, the zeolite particle has a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.

Method for treating arsenic-containing aqueous solution

Provided is a method for decomposing at least one of organic compound contained in an aqueous solution by using a titanium dioxide photocatalyst that is excellent in both photocatalytic activity and solid-liquid separation performance for water treatment. The method includes: a step of adding catalyst particles into the aqueous solution; a step of decomposing the organic compound by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and a step of stopping the stirring, and separating the catalyst particles from the aqueous solution by sedimentation. The catalyst particles are composed only of titanium dioxide particles and zeolite particles, the titanium dioxide particles are adsorbed on outer surfaces of the zeolite particles, the zeolite particles have a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.

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Osaka, Japan

Yuko Maruo