Hitachi, Ltd.

Makoto Onishi

Masami Ito

Shinjiro Ueda

Shinichi Yoshikawa

Kiyokazu Takemura

Hajime Kato

Minoru Morita

Toshiki P Tanaka

Yoshio Nakayama

Mitsuo Tanaka

Katsuyuki Nagano

Sadao Matsuoka

Shigeki Terui

An oil content measurement device includes a fluid device which mixes water to be treated containing oil content with a solvent and extracts the oil content into the solvent, a sensor unit which has a casing storing a quartz crystal oscillator therein with a ring-like spacer in between, a dispensing nozzle which is disposed above the oscillator at a predetermined gap there between and feeds a predetermined amount of the solvent after the oil content has been extracted on the oscillator, a sensor circuit which measures a resonance frequency of the oscillator, and controller which controls at least the fluid device and the sensor circuit. Provided is a arithmetic logical unit, based on a change amount of the received resonance frequency of the oscillator in the sensor unit to which the solvent after the oil content has been extracted has been fed, measures the oil content remaining on the oscillator.

Oil content measurement device

A sewage treatment apparatus includes a membrane separation active-sludge treating section which performs a biological treatment on a part of sewage, which is introduced by a water introducing section while flowing through a sewer trunk line, to generate first treated sewage; a membrane highly treating section which performs a membrane high treatment on the first treated sewage to generate second treated sewage; a membrane treating tank which stores the first treated sewage; a membrane highly treating tank which stores the second treated sewage; water level sensors which respectively measure water level of the membrane treating tank and the membrane highly treating tank; and a power-control section which controls water introducing quantity of the water introducing section on the basis of the water level data measured by the water level sensors.

Sewage treatment apparatus and sewage reuse system

A sewage reuse system distributes a plurality of reuse water supply sections, each including a water introducing opening formed in a sewer trunk line; a treated sewage tank for storing reuse water; and a water level sensor for measuring a water level of the treated sewage tank, in a demand area of reuse water along the sewer trunk line. The system includes a movable sewage treatment section which moves to any of the plurality of water introducing openings; performs the sewage treatment to generate reuse water; and supplies the generated reuse water to the treated sewage tank, a communication section which transmits the water level data measured by the water level sensor, and a central control section which controls a water storing quantity of the treated sewage tank on the basis of the demand information of reuse water and the water level data.

Sewage reuse system

In an optical fiber connector, the pair of optical fibers to be connected together are placed end-to-end in a linear groove which has been formed on a lateral surface of a central cylinder. They are held fixed by a holding member which is fitted in the groove and is moved towards the optical fibers according to the rotation of a hollow cylinder which externally touches the central cylinder, whereby the optical fibers can be connected with a precise alignment and accordingly with a low optical power loss.

Optical connector

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Tokyo, Japan

Makoto Onishi