JPS6068093A - Water treating system - Google Patents

Abstract

PURPOSE:To obtain inexpensively the purified water without using a special water feed pump by filtering the water to be treated with a porous hollow yarn membrane impermeable to bacteria, allowing to pass through an activated carbon layer, and then filtering with another porous hollow yarn membrane. CONSTITUTION:The bacteria, pyrogens, colloidal substances, low molecular organic compds. contained in the water are almost completely removed in a filtration part A by a filter medium consisting of a porous hollw yarn membrane wherein a multitude of slit micropores are present. The water, after passing through the filtration part A, is sent to an activated carbon type water treating part B wherein the stinky substances, etc. are collected, and then sent to a filtration part C wherein the purified water is obtained. A porous hollow yarn made of polyolefins having 300-5,000Angstrom mean width, 8-50 ratio of length to width and contg. a multitude of slit micropores distributed in the longitudinal direction of the fiber is suitably used as the membrane for the filtration part A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water treatment system for purifying water. More specifically, it concerns water treatment systems that remove bacteria, pyrogens, colloidal substances, low-molecular organic compounds, chlorine, and other malodorous substances that are contained in well water, tap water, etc. The present invention relates to a low-cost system that can easily obtain high-purity water required for medical use, precision physical and chemical experiments, food industry use, drinking water use, etc.

Regarding water purification systems, various types of systems have been considered and are commercially available, but it is extremely difficult to completely remove the above-mentioned substances. In order to completely remove such substances, advanced water treatment technologies such as distillation and reverse osmosis membranes are required, but these systems have high energy and equipment costs, and are difficult to purify water at low cost. It has the disadvantage that it cannot be used.

It is known that activated carbon water treatment equipment is equipped with a pre-filter, but this pre-filter only removes large particles in the water, such as low-molecular organic compounds, colloidal substances, and pyrogens (pyrogenic substances). , bacteria, etc. cannot be removed sufficiently.

Moreover, since no measures are taken to prevent the outflow of fine particles due to deterioration of activated carbon, it is not possible to obtain high purity water, although it is low cost. In addition, in order to remove bacteria and fine particles, a method is known in which membrane modules with commercially available straight-bore micropores with small pore diameters are installed before and after the activated carbon layer, but in this case, it is difficult to obtain a large filtration flow rate. If you try to increase the flow rate, you will need a high pressure, and the processing efficiency will be significantly reduced due to clogging in a short period of time, making it impractical.

It is also necessary to remove substances that cause bad odors, but the cause of these bad odors is significant water pollution of tap water sources due to regional development and domestic sewage. This tendency is particularly remarkable when the water source is lake water. In particular, due to eutrophication of lake water, the occurrence of red tide due to the mass proliferation of phytoplankton and the occurrence of foul-smelling river edges have been observed. This odor is often caused by substances secreted by cyanobacteria or microorganisms such as actinomycetes that adhere to organic matter deposited on the lake bottom. In order to remove these malodorous substances, water purifiers for household use that pass treated water through an activated carbon layer have recently been commercially available. In addition, in the food industry, water purification systems based on sea urchin activated carbon adsorption are widely used, as they do not have a negative impact on products. However, in the case of water purification systems using activated carbon, the activated carbon layer becomes a breeding ground for bacteria due to long-term use, resulting in two hygiene problems.

It is therefore an object of the present invention to provide a water treatment system that does not have the above-mentioned drawbacks and is inexpensive.

In view of this objective, the present inventors have completed the water treatment system of the present invention as a result of intensive research.

The water treatment system of the present invention includes a plurality of m-recess sections each having a porous hollow fiber membrane having micropores, and at least one activated carbon layer between the filtration sections. At least one of the filtration sections in front of the 1g activated carbon bed does not allow bacteria to pass through.

As the hollow fiber membrane used in the present invention, any hollow fiber membrane can be used as long as it is combined with a membrane that does not allow bacteria to pass through or, furthermore, that does not allow active substance fine powder to pass through. However, it is preferable to use one that can also block pyrodiene, and polyolefins such as polyethylene and polypropylene are particularly preferable. Furthermore, the hollow fiber membrane has an elongated cylindrical shape, and the wall thereof is preferably porous, with many strip-shaped micropores present therein. The thickness of the wall is 5 to 150μ, and the diameter of the opening of the hollow space is 100 to 300μ.
The porosity is preferably about 30 to 70% by volume. The micropores are oriented in the II Ilt length direction, and the average width is 3
00~5000A, and its length to width ratio is 8~50
It is preferable that When the length to width ratio is smaller than 8, it is possible to capture even smaller objects, but the flow rate is reduced.

On the other hand, when this ratio becomes larger than 50, I: the film becomes weaker and the pressure resistance decreases.

The micropores communicate from the inner wall surface to the outer wall surface of the hollow fiber membrane. Water passes through the pores, but substances such as bacteria are trapped. Such a porous hollow fiber membrane having strip-shaped micropores can block smaller substances than a conventional straight-bore type membrane, and can form a filtration section with high filtration performance.

It also has superior performance in removing low-molecular organic compounds compared to straight bore type membranes.

In the activated carbon layer provided in the middle of the filtration section, various activated carbons can be used depending on the quality of the water to be treated, and for example, granular coconut shell activated carbon is preferable. Since the live carbon bed has at least one filtration section in front of it that does not allow bacteria to pass through, it can always be kept in a sterile state, making the water treatment system sanitary.

Furthermore, by providing a porous hollow fiber membrane filtration section downstream of the activated carbon layer, fine 11T1 generated due to deterioration of activated carbon can be removed.
'J powder can be prevented from flowing out.

Next, the water treatment system of the present invention will be explained in more detail according to the drawings.

FIG. 1 shows an embodiment of the water treatment system of the present invention. The water treatment system shown in FIG. 1 is composed of a filtration section made of porous hollow fiber membranes indicated by A and C, and an activated carbon type water treatment section B installed between the filtration sections.

Specifically, the porous hollow fiber membrane used for A and C('f)i11 is preferably a polyolefin membrane made of polypropylene, polyethylene, or the like.

This porous hollow fiber membrane has an average width of 300 to 50, for example.
00A, the length to width ratio is 8 to 50, IJi Iff has many slit-like micro holes oriented in the longitudinal direction, the hole skewer is about 30 to 70% by volume, and the diameter of the opening of the hollow space is 100 to 3
00μ, and the thickness of the wall film layer is preferably about 5 to 150μ.

In the filtration section, the porous hollow fiber membrane (1) is bent into a bundle and bent, for example, into a U-shape as shown in Fig. 1, and the vicinity of both ends is filled with, for example, polyurethane resin without sealing the opening of the hollow space. It is adhesively fixed to the fixing part (2) using an adhesive or the like. The hollow fiber membrane module thus produced is housed in a container having a water intake port and a drainage port.

Activated carbon type water treatment units use various types of activated carbon depending on the quality of the water to be treated. For example, there is one in which a container is filled with granular coconut shell activated carbon.

Next, the water place J in Figure 1! 1′! Explain how the system works. Bacteria m contained in the water in the filtration part of A,
Pyrodiene, colloidal substances, low-molecular organic compounds, etc. are used in porous hollow fiber membranes with many slit-like micropores:
It is almost completely removed by a separate filter medium. The water that has passed through the filtration section Δ is subjected to an activated carbon type water treatment section B in which odor substances and the like in the water are captured, and then passes through the filtration section C to obtain purified water.

Since the filtration section Δ uses a porous hollow fiber membrane having a special VA fine structure as described above, the above-mentioned substances can be almost completely removed. However, since chlorine as a disinfectant and the above-mentioned odor components as secretions from algae are not removed, they are removed in part B. In addition, the ful1 particulate matter accompanying the deterioration of the activated carbon in the B part can be removed by the C part. Furthermore, since bacteria can be completely removed by the filtration section A before B, B can be kept partially sterile.

The water treatment system of the present invention can provide sufficient water output simply by connecting it to a water faucet, for example. This is because porous hollow fiber membranes with a large effective filtration area are used for the filtration media in the hem part and the 0 part, and the filtration resistance is small. Therefore, there is no need to use a special water pump or the like, and purified water can be obtained at low cost.

2-5 show another embodiment of the water treatment system of the present invention. The systems in Figure 2 are A and B.

Three porous hollow fiber membranes J: C have a filtration section and an activated carbon type water treatment section B. In the system I\ shown in Fig. 3, different types of active +1
An activated carbon type water treatment section [and F] are provided. Fourth
In the system shown, each of the two active i3'J water treatment units is
Each is sandwiched between filter sections. Also, as shown in Fig. 5, one housing is divided into three spaces, and two filter parts Δ
It is also possible to provide an activated carbon type water treatment section B between and C.

In this way, in the present invention, at least one activated carbon treatment section is provided between the filtration section made of a plurality of porous hollow fiber membranes and between the filtration sections. As long as at least one of the preceding filtration parts does not allow bacteria to pass through, it can be of the scale type. Next, an example of water treatment using the water treatment system of the present invention will be shown.

Example 1 In the system shown in FIG. 1, the filtration parts A and C were made of a polyethylene porous hollow membrane with a porosity of 63% by volume, a membrane width of 60μ, and a pore diameter (inner diameter) of 270μ at the mouth of the hollow space. Activated carbon type water treatment 4 Part B was filled with granular V-cigara activated carbon. This water treatment system filtered pond water by applying a water pressure of 1 Kg/Cd using a pump. Water quality tests were conducted on the water before and after filtration. The results are shown in the table below.

Comparative example - Using a commercially available straight bore type flat membrane module with a pore diameter of 0.2μ and a filtration area of 0°5cm' in the front stage of the Shigara activated bamboo charcoal water treatment section, the water pressure I K Q'/
ct? and filtered the pond water. The initial flow is 1, 2
t/min, but the flow rate after 3 hours of filtration was 015j/min.
It decreased to min. In order to prevent a decrease in flow rate, filtration was performed using a straight-bore type flat membrane module with a pore diameter of 0.6 μ and a filtration area of 0.5 m. In this case, a bacterial test in the filtrated water showed that 33 bacteria/ml. General bacteria were detected.

[Brief explanation of the drawing]

1 to 5 show respective embodiments of a water treatment system 11 having a filtration section and an activated carbon layer section of the hollow fiber membrane module of the present invention. A, C, D+ A filtration section made of a porous hollow fiber membrane having a large number of slit-like micropores. B, E, F: Activated carbon layer part 1: Hollow fiber membrane 2: Adhesive fixing part 3.4: Granular coconut shell activated carbon Patent application agent Yukizo Tsuchiyama Saki

Claims (1)

[Claims] (1) A water treatment method, which comprises filtering the water to be treated through a filtration section made of a porous hollow fiber membrane that does not allow bacteria to pass through;
A method comprising then filtering through a layer of activated carbon and then through another filtration section consisting of a porous hollow fiber membrane. (2. The method according to claim 1, wherein the porous hollow fiber membrane is made of polyolefin. (3) The method according to claim 1 or 2. In the method, the porous hollow fiber membrane has a hollow cylindrical shape with a thickness of 5 to 150 μm, and has a large number of strip-shaped micropores oriented in the m length direction, and the micropores have an average of 300 to 150 micropores.
It has a width of 5000△, and the ratio of width to goodness is 8 to 5 on average
0, and the micropores are in communication from the inner wall surface to the outer wall surface of the hollow fiber membrane. (4) It has a plurality of filtration sections made of porous hollow fiber membranes and at least one activated carbon layer provided between the plurality of filtration sections, and at least one of the filtration sections before the activated carbon layer. A water treatment device characterized in that it does not allow bacteria to pass through. (5) In the device according to claim 4,
An apparatus characterized in that the porous hollow fiber membrane is made of polyolefin. (6) In the device according to claim 4 or 5, the porous hollow fiber membrane has a hollow cylindrical shape with a thickness of 5 to 150μ, and has a plurality of INs oriented in the longitudinal direction. It has strip-shaped micropores, and the micropores have an average of 300 to 300 micropores.
boooo human width, with an average length-to-width ratio of 8 to 5
o, and the micropores are in communication from the inner wall surface to the outer wall surface of the hollow fiber membrane.