JPH0630793B2 - Water circulation system - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a water circulation treatment system for purifying a drainage pipe and reusing it as drinking water or the like, and particularly to a recycle system in a closed space such as a space station or a submarine. The present invention relates to a water circulation system suitable for use.

[Background of the Invention]

Conventionally, as a water treatment technology for treating and reusing wastewater, Japanese Patent Laid-Open No. 55-35972, or technical magazine "Nikkei Mechanical" May 21, 1984, p55, "Super 256K Bit Support" As the content is introduced as "total mobilization of pure water production equipment, membrane material, piping, and measurement technology", there are treatment technologies using membranes such as ultrafiltration and reverse osmosis, which can be used individually or in combination. Purify water. However, in extremely limited space such as outer space, and in order to highly purify wastewater until it can be used for beverages, removal of organic substances by conventional ultrafiltration and reverse osmosis is insufficient. There are some drawbacks such as high operating pressure, low water recovery and so on.

[Object of the Invention]

An object of the present invention is to purify drinking water (shear water, urine, soap water, plant cultivation drainage, culture drainage, etc.) discharged from humans or animals and plants in a closed space such as a space station or a submarine, and drinking water. The purpose is to provide a water circulation treatment system for water for daily use, water for cultivation, and the like.

[Outline of Invention]

A feature of the present invention is that the so-called thermopervaporation method using a hydrophobic porous membrane as a separation membrane is used as a means for separating impurities from wastewater, and in order to maintain the hydrophobicity of the membrane, a thermopervaporation As a pretreatment, an organic substance removing means such as activated carbon adsorption is provided.

Another feature of the present invention is to send the wastewater concentrated by the thermopervaporation method to a solid matter separation device such as a crystallizer, and the supernatant liquid from which the solid matter is separated is treated again by the thermopervaporation method. It is to collect purified water up to 100% with high efficiency.

Fig. 1 shows the principle of the thermo-pervaporation method.
The membrane used here is a so-called hydrophobic porous membrane, and the wastewater in contact with the membrane surface is heated and a part thereof is evaporated on the membrane surface. The vaporized vapor passes through the pores (0.1 to 1.0 μm) of the film, diffuses to the cooling surface provided facing the film, and is cooled and condensed here. Since the condensed water has undergone a two-stage separation operation of evaporation and membrane permeation, 99.99% or more of the impurities in the waste water have been removed, resulting in extremely high purity water. Here, since the energy for purifying the wastewater has a temperature difference, the energy for heating the wastewater may be supplied from an electric heater, or the wastewater may be directly heated by the heat of the exhaust heat system. In a spacecraft or the like, a large amount of exhaust heat is generated from various electronic devices and control devices, and thus it is possible to effectively use the exhaust heat as a heat source.

The material of the hydrophobic porous membrane used here is usually PT
FE (polytetrafluoroethylene) polypropylene or the like is used, and the pore size is 0.1 to 1.0 μm.

Fig. 2 shows the experimental results showing the permeated water amount Q per unit membrane area and the electric conductivity of the obtained permeated water when the wastewater containing 3.4 wt% NaCl as an impurity was purified by the thermo-pervaporation method. Is. As shown in the figure, the permeated water amount Q is linearly proportional to the vapor pressure difference ΔP between the waste water (high temperature) and the cooling water (low temperature). The conductivity of the permeated water does not depend on ΔP, but on average it is 10 μs / cm, and the conductivity of the drainage is about 48 ms / c.
It is more than 4 orders of magnitude lower than m and is extremely high in purity.

Example of Invention

 An embodiment of the present invention will be described below with reference to FIG.

Wastewater discharged as a result of human life in the spacecraft or breeding and cultivation of animals and plants is a device that first removes fine solids with a prefilter 1 such as a cartridge filter and then adsorbs and removes organic substances such as activated carbon. At 2, the organic matter in the waste water is removed. The organic matter is removed in order to maintain the hydrophobicity of the hydrophobic porous membrane used in the subsequent thermopervaporation. When organic substances such as surfactants in wastewater adhere to the surface of the hydrophobic membrane, the surface of the membrane becomes hydrophilic and the wastewater directly passes through the pores of the membrane, so be especially careful to maintain hydrophobicity. I have to.

The wastewater from which the organic substances have been removed then enters the thermo-pervaporation membrane separation device 3, and the membrane permeated water 5 is obtained according to the principle shown in FIG. Since the membrane-permeated water has an extremely high purity as shown in FIG. 2, it can be used as drinking water or other domestic water.

On the other hand, the wastewater that does not pass through the membrane is gradually concentrated, and if the soluble impurities in the wastewater exceed the solubility, they will precipitate as a solid matter. Therefore, they are sent to the crystallizer 4 by the preconcentrated concentrated water pipe 6 where they are deposited. The precipitated solid 7 is separated. After the solids are separated, the supernatant water return pipe 8 enters the pervaporation membrane separator 3 again. Therefore, the permeated water can be recovered from the wastewater with high efficiency and can be used again.

Here, as the heating source 9 for heating the waste water in the thermo pervaporation device, exhaust heat generated from electronic devices and control devices used in the spacecraft is used.

Another embodiment of the present invention is shown in the block diagram of FIG. Here, the wastewater 100 is first pretreated by the prefilter 1 ultrafiltration 11 and reverse osmosis 12 to remove most impurities. As the water quality to be reused, treated water up to reverse osmosis 12 is used as shower water, animal and plant breeding water 110, which can be used without highly purified like drinking water. For water that needs to be highly purified, such as drinking water 120, the permeated water in reverse osmosis 12 is treated with activated carbon 13 and this is purified with pervaporation 3. By doing so, the amount of processing in the pervaporation 3 can be small, and therefore the apparatus can be made more compact.

〔The invention's effect〕

According to the present invention, since the wastewater is treated by the thermopervaporation method using the hydrophobic porous membrane, the wastewater can be purified by the two-step operation of evaporation and membrane separation, and extremely high-purity water can be obtained.
It can be obtained with a small device. Further, since the apparatus for removing organic substances such as activated carbon is provided as the pretreatment, there is an effect that the hydrophobicity of the membrane can be maintained and stable operation can be performed.
Further, the concentrated water of the pervaporation can be treated with a crystallizer to separate the precipitated solid matter, so that the purified water can be recovered from the waste water with high efficiency. Furthermore, when this system is used in a spacecraft, the exhaust heat generated in the spacecraft can be used directly as the heat source of the thermo-pervaporation, and the wastewater treatment cost can be reduced. There is.

[Brief description of drawings]

FIG. 1 is a model of wastewater treatment for thermopervaporation membrane separation, FIG. 2 is an experimental result of treating model wastewater by the thermopervaporation membrane separation method, and FIG. 3 is one embodiment of the present invention. A wastewater treatment system, the fourth is a wastewater treatment system which is another embodiment of the present invention. 1 ... Prefilter, 2 ... Organic matter removing device, 3 ...
Thermopervaporation membrane separator, 4 ... Crystallizer, 5 ... Membrane permeate, 6 ... Concentrated water pipe, 7 ... Solid matter,
8 ... Return tube, 9 ... Heating source.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hideaki Kurokawa 4026 Kuji Town, Hitachi City, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory Ltd. Hitachi, Ltd. (72) Inventor Akira Ashida 4-6, Sugawadai Kanda, Chiyoda-ku, Tokyo Hitachi, Ltd.

Claims (3)

[Claims] 1. A water circulation treatment system for purifying wastewater generated from human-life and breeding and cultivating equipment for animals and plants in a closed space such as a spaceship or submarine and reusing it as drinking water or other water. A water circulation system that uses organic matter membranes for wastewater treatment and features an organic matter removal device such as activated carbon in front of a water treatment device that uses a hydrophobic porous membrane. 2. The method according to claim 1, wherein the wastewater concentrated by the hydrophobic porous membrane is introduced into a crystallizer to separate the solid matter in the concentrated wastewater, and the supernatant liquid is again made into the hydrophobic porous material. A water circulation system characterized by being introduced into a water treatment device using a membrane. 3. The water circulation system according to claim 1, wherein exhaust heat generated in a spacecraft or the like is used as a treatment energy source of the water treatment device using the hydrophobic porous membrane.