JPH0199689A - Method for removing organic matter in water - Google Patents

Abstract

PURPOSE:To continuously oxidize and decompose org. matter and to reduce running cost by treating org. matter-contg. water with contact catalyst filter media in the presence of a chlorine oxidizing agent, etc., and removing the org. mater by oxidation decomposition. CONSTITUTION:A filter cylinder 1 consisting of a raw water tank 2 and a contact catalyst filter medium layer 5 packed on a supporting gravel layer 6 is connected via a water flow passage 3 and an oxidizing agent injection part 4 is provided on the mid-point of the water flow passage 3. Sodium hypochlorite is used as the oxidizing agent and beta type manganese dioxide particles, etc., are used as the contact catalyst filter media. The org. matter in the water is efficiently removed if the sodium hypochlorite is injected to the oxidizing agent injecting part 4 and the residual free chlorine of the treated water 7 past the filter cylinder 1 of the contact catalyst filter medium layer 5 is maintained at about >=0.1mg/l with the residual free chlorine as an index.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J This invention relates to a treatment method for removing organic substances present in water such as water, sewage and industrial water.

[Conventional technology]

Conventionally, methods for removing organic matter from water include coagulation sedimentation filtration treatment, activated carbon adsorption treatment, biological oxidation treatment, and the like.

In the coagulation-sedimentation filtration treatment method, insoluble organic matter 1 organic matter with a large molecular weight is removed by injection of an appropriate flocculant, but organic matter with a small molecular weight is not removed.

Activated carbon adsorption treatment removes organic matter with a small molecular weight, contrary to the coagulation-sedimentation filtration treatment method, but it does not remove organic matter with a large molecular weight.Also, since there is a limit to the adsorption capacity, it is necessary to carry out running operations such as regeneration and replacement of activated carbon. It costs a lot. In the biological oxidation treatment method, the removal rate decreases due to a decrease in water temperature, and changes in the load of raw water have a large effect on the treated water, making it impossible to obtain a stable removal rate.

[Problem that the invention seeks to solve]

This invention removes organic matter from water using conventional coagulation-sedimentation filtration treatment methods, activated carbon adsorption treatment methods, biological oxidation treatment methods that require incidental equipment and regeneration equipment, and also uses manganese sand in a contact oxidation furnace. This is an improved treatment method that removes chromaticity by catalytic oxidation, and is a treatment method that efficiently removes organic substances. That is, oxidative decomposition was carried out continuously over the entire height of the filter layer using a highly activated oxidation contact catalyst filter medium. The purpose is to provide a processing method that requires almost no running cost.

Furthermore, the treatment method of this invention can be applied to the rapid sand i-filtration system, which is one of the existing water purification processes, and can be applied to the original 5
In addition to the filtration function, it can also have the function of removing organic matter at the same time.

EMeans to solve the problemJ This invention is used in the removal of organic matter in water.

This is a method for removing organic matter in water by oxidizing and decomposing organic matter in water by using a catalytic filter medium in the presence of an oxidizing agent. The amount of these organic substances is TOC (total organic carbon), MnOm (potassium permanganate) consumption, E
It is detected using an index such as 260 (ultraviolet absorbance 260r+11).

This invention uses β-type and γ-type mankan dioxide particles of electrolytic manganese dioxide, which have high activity, as a contact catalyst material.
In the presence of an appropriate oxidizing agent such as chlorine gas or primary sodium hypochlorite, water containing organic substances is simply passed through the catalytic material layer and filtered, and the catalytic material layer Organic matter in water is oxidized and decomposed and removed by the oxidizing action of an oxidizing agent. Since this oxidative decomposition of organic matter is carried out over the entire layer height of the catalytic catalyst door material, organic matter can be removed continuously and reliably.

As the oxidizing agent, in addition to chlorine gas, sodium hypochlorite, and other chlorine-based oxidizing agents, hydrogen peroxide, potassium permanganate, or ozone, which has stronger oxidizing power, can be used.

As the catalyst material, β-type manganese dioxide particles and γ-type manganese dioxide particles of electrolytic manganese dioxide, which are filter media with a larger specific surface area and higher catalytic activity than conventional manganese sand, are suitable. Crystallographically β-type and γ-type 2
Mixed-phase manganese dioxide particles, or these β-type, γ-type
A mixture of type manganese dioxide particles and β-γ mixed phase type manganese dioxide particles can be used, but the material is not limited to these as long as it has the above-mentioned function of catalyzing oxidation in the presence of an oxidizing agent.

γ-type manganese dioxide includes naturally produced rum sprite,
Artificial electrolytic manganese dioxide is used, and when the heat treatment temperature reaches 200°C or higher, some β-type manganese dioxide is generated and transformation begins.
β-γ mixed phase manganese dioxide or β-type manganese dioxide can be obtained.

In this invention, indicators of organic matter used include OC (total organic carbon), KMnO, (potassium permanganate) consumption, and E260 (ultraviolet absorbance). T
OC is the amount of carbon in organic matter present in water, and indicates the absolute amount of organic matter, and potassium permanganate is eliminated'4! & amount is
E260 indicates the amount of organic matter that is oxidized by KMnO under appropriate conditions, and E260 indicates the organic matter (organic matter with double bonds) that exhibits absorption at an ultraviolet wavelength of 260n+i. Since the rate of change in removal of organic matter is displayed linearly, the rate of removal of organic matter can be clearly detected.

Of these indicators, only potassium permanganate consumption is listed as a water quality standard (10
+wg/Q).

In recent years, with the development of analytical techniques, methods for removing trace amounts of organic matter have been studied. Recently, there has been a demand for improving the quality of drinking water such as "tasting water", and as for the organic matter in drinking water, the amount of potassium permanganate consumed has increased to 3.0 m
A target value of g/Q or less is being established.

[Function/Example] As shown in the attached drawing, the device for carrying out the present invention includes an S filter cylinder 1 consisting of a raw water tank 2 and a catalytic catalyst filter layer 5 filled on a support gravel layer 6. 3, and an oxidizing agent injection part 4 is provided in the middle of this water passage 3.

As mentioned above, the filter cylinder 1 had an inner diameter of 25 m, a manganese dioxide filter layer thickness of 700 m, an effective manganese dioxide diameter of 0.43 m, and a uniformity coefficient of 1.40.

In this example, sodium hypochlorite was used as the oxidizing agent, β-type manganese dioxide particles, γ-type manganese dioxide particles, or mixed particles of β-type and γ-type manganese dioxide were used as the catalyst material. A conventional treatment method using manganese sand was used.

To control the injection of sodium hypochlorite, which is an oxidizing agent, secondary sodium hypochlorite is injected into the acid (arsenic agent injection part 4) in the middle of the water passage 3, and the free residual chlorine is used as an indicator to control the contact catalyst system. Treated water 7 that has passed through the door material layer 5 filter tube 1
If the free residual chlorine in the water is approximately 0.1 mg/Q or more, organic matter in the water can be efficiently removed. The test results are shown in Tables 1 and 2.

Table 1 shows the water flow conditions when the space velocity is 5V=6, and Table 2 shows the water flow conditions when the space velocity is 5V=1O. (Note) Water flow conditions: Space velocity 5V=6 The above test results table As shown, it can be seen that the treatment method of the present invention is superior to conventional treatments in terms of removing organic matter. Note that it can be removed more effectively by using an oxidizing agent such as ozone that has an oxidizing power greater than that of sodium hypochlorite.

Applications of this invention 1. For example, rapid sand is a process of coagulation/sedimentation/filtration system which is a common water purification method at present; In the presence of a suitable chlorine-based oxidizing agent, by using existing injection equipment, such as chlorine gas or secondary sodium hypochlorite, which are commonly used for disinfection and sterilization in water purification, by replacing manganese particles etc. in;
By filtration, it can be used in many ways in addition to the conventional filtering function.
The first advantage is that σ can be easily removed and the amount of coagulant to be injected can be reduced.

[Effects of the Invention] The method of removing organic matter contained in water according to the present invention removes organic matter-containing water from water in the presence of an oxidizing agent.

This method removes organic matter by oxidation and decomposition by passing it through a contact catalytic material layer consisting of a particle layer of highly activated β-type and γ-type manganese dioxide.
, consumption 1i, To+:.

This is a simplified treatment method in which the amount of organic matter removed can be clearly detected by detecting with E260 or the like.

In addition, the removal rate is higher than the conventional treatment method using mankan sand, and furthermore, unlike the granular activated carbon treatment method or ozone treatment method, existing equipment can be used without the need for regeneration equipment or ancillary equipment, and running costs are low. It is almost the same level as the current rapid 5 filtration system, and there is no running cost such as activated carbon regeneration cost in the granular activated carbon treatment method or electricity cost in the ozone treatment method, and it is cost-effective for treating water containing organic matter. This is an extremely effective treatment method.

[Brief explanation of the drawing]

The attached drawing is a system diagram of the apparatus to carry out the method of the present invention.9 In the figure, ■ Filtration vortex section 2 Raw water tank 3 Water passage 11 Acid 1 arsenic injection section 5 Contact catalyst filter medium 6 Support gravel layer 7 Treated water It is.

Claims (3)

[Claims] (1) In the removal of organic matter from water, in the presence of an oxidizing agent,
A method for removing organic matter in water, which is characterized by oxidatively decomposing and removing organic matter by using a catalytic catalytic filter medium. (2) Organic matter in water according to claim 1, wherein the oxidizing agent is chlorine gas, a chlorine-based oxidizing agent such as sodium hypochlorite, ozone, hydrogen peroxide, or potassium permanganate. Removal method. (3) Single use of β-type manganese dioxide particles, γ-type manganese dioxide particles, crystallized β-type and γ-type two-phase mixed manganese dioxide particles, or each of these types of manganese dioxide using electrolytic manganese dioxide as the contact catalyst filter material The method for removing organic matter in water according to claim 1 or 2, characterized in that the method is a mixture of particles.