JPS58163491A - Removal of phosphorus dissolved in water - Google Patents

Abstract

PURPOSE:To perform efficient dephosphorization by filtration only, by using the catalytic filtering agent where the catalytic interfaces of oxidized metal such as iron are formed on the surface parts of filtering particles, and filtering phosphorus-dissolved raw water in the presence of the sufficient amounts of dissolved oxygen and ferrous ion. CONSTITUTION:Oil carbon is mixed with dried clay, iron oxide is added to the mixture to impregnate particles, and the resulting particles are baked at about 850 deg.C for 30-60min in the absence of oxygen and then sieved to obtain a filtering agent 2. The filtering agent 2 is piled up to thickness of 1m on a filtering bed 3 in a filtering tank 1, to constitute a filtering layer. On the occasion of filtration, pressurized air is charged in a pipe 4 for the inflow of raw water to hold the sufficient amount of dissolved oxygen in the phosphorus-dissolved raw water. Thereafter, a ferrous sulfate solution is injected into the raw water from a connecting pipe 5 connected to the pipe 4 for the inflow of raw water. After the raw water is filtered in the filtering tank 1 under the condition of LV= 12.5m/H and SV=12.5l/H, it is withdrawn through a pipe 7 for with-drawing purified water.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing phosphorus dissolved in water.

In general, phosphorus dissolved in water, together with nitrogen, is a major source of pollution that contributes to the high nutrient content of water. However, the former method, i.e., the method using lime or metal salts, has the problem of generating sludge, and the latter method, i.e., the method using phosphate rock, has problems such as not being able to obtain sufficient r-speed. Currently, there is a need for improvement.

This invention has been made in view of the above circumstances, and is characterized in that it dephosphorizes phosphorus dissolved in water by only r-over-operation without performing a coagulation operation, and at an f-speed faster than conventional methods. The purpose is to provide a removal method.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First, as shown in the drawings, a closed filtration tank 1 in which a contact catalyst material 2 is arranged is prepared so as to be advantageous for increasing dissolved oxygen in raw water. In this case, for example, an iron oxide contact catalyst F material is used as the R material 2. For example, oil carbon is mixed with dry clay, iron oxide is added thereto, the mixture is granulated, and the mixture is heated to a temperature of about 850°C. After firing for 30 minutes to 1 hour in the absence of oxygen, the material is sieved to obtain R material 2. In addition,
The analysis ratio of the components of this r material 2 is as shown in the table below.

Note that the above analysis method is a mutatis mutandis application of JIS R, -5202 Portland cement analysis method.

A filtration tank 1 is made of R material 2 formed as described above with one layer thickness.
It is laminated on top of the f-floor 3 to form one layer. During filtration, pressurized air connected to a compressor (not shown) is fed into the raw water inflow pipe 4 to make sufficient dissolved oxygen exist in the raw water containing dissolved phosphorus, and then the connecting pipe connected to the raw water inflow pipe 4 is 5, inject the ferrous sulfate solution into the raw water and place the raw water in the filtration tank 1, LV = 12.5 ~ MSV = 1
Filter under conditions of 2.51/H. In addition, when filtering,
Excess air in the raw water is discharged by a safety valve 6 provided at the top of the filtration tank 1 to prevent air bubbles from forming in the r layer. Note that 7 is a treated water outlet pipe.

As a result of the experiment conducted as described above, the phosphorus removal status is as shown in the table below. In this case, the reaction between phosphoric acid and ferrous sulfate is as follows. That is, 3Fe+ 2PO4→Fea(PO4)2 where, Fe
5(po4)2 is FePO4 in an oxygen atmosphere
Changes to Then, this reaction progresses on the surface of the r material,
Although this product adheres to the surface of the f-material and becomes thick, no deterioration of the catalyst function is observed, and after a certain period of time, one layer of backwashing can be carried out to restore the filtration function.

In the above embodiments, the case where the catalytic catalyst filtration is an iron oxide catalytic catalyst is shown, but it is not necessarily limited to this iron oxide, and any catalyst that can oxidize ferrous iron to ferric iron may be used.

As explained above, according to the method for removing phosphorus of the present invention, only a filtration operation is required without performing a flocculation operation, and
Since the f-speed is faster than the conventional method using phosphate rock, for example, the r-speed is about three times faster, excellent effects such as the ability to reduce the installation area and perform the dephosphorization operation efficiently can be obtained. , its utility value is remarkable.

[Brief explanation of drawings]

The drawings are explanatory diagrams showing an example of the method of the present invention. In the figure: 1 Sealed filtration tank 2 Catalyst catalyst material 3F Floor
4 Raw water inflow pipe 5 Connection pipe 6
Safety valve 7 This is a pipe for taking out treated water. Patent applicant Suido Kiko Co., Ltd.

Claims (1)

[Claims] A catalytic catalyst material with a catalytic interface made of an oxidized metal such as iron is prepared on the particle surface of the material, and this material is used to catalyze raw water containing dissolved phosphorus in the presence of sufficient dissolved oxygen and ferrous ions. 1. A method for removing phosphorus dissolved in water, which is characterized by converting phosphorus into an insoluble substance and removing it by causing a reaction between the two through the intervention of a contact catalyst.