JPS61157391A - Removal of ss and phosphorus in sewage - Google Patents

Abstract

PURPOSE:To efficiently remove SS phosphorus, by withdrawing a part of a filter material from the lower part of a filter material bed and transferring the withdrawn filter material to the upper part of the filter material bed while regenerating the same by the addition of an acid or alkali. CONSTITUTION:Calcium and alkali agents are injected in sewage supplied through a sewage introducing pipe 1 from a calcium agent/alkali agent introducing pipe 2 and mixed in an inline mixer 3 to be introduced into a reaction tank 4 packed with a dephosphorization material. The sewage introduced into the reaction tank is distributed by a distribution cone 5 to be flowed upwardly through a dephosphorization material bed to remove phosphorus and the treated water is discharged from a treated water discharge pipe 13. By blowing air into the lower part of a transfer pipe 9, a part of the dephosphorization material is transferred upwardly through the transfer pipe. An acid is injected in the lower part of the transfer pipe through an acid introducing pipe 8 and mixed by air.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for removing SS and phosphorus contained in wastewater such as sewage, human waste water, or industrial wastewater.

[Conventional technology and its problems]

In recent years, with the progress of eutrophication of closed water bodies, research on methods for removing SS and phosphorus from wastewater flowing into these water bodies has been conducted in various places.

The method of treating sewage by bringing it into contact with a dephosphorizing agent such as phosphate rock or bone charcoal is well known among those skilled in the art as the contact phosphorus method, and this method reduces the generation of sludge. Therefore, it is expected to be a promising method.

However, in this method, if water continues to flow for a long period of time, the dephosphorization material (filter material) becomes contaminated with OaOO3 and organic matter, and the quality of the treated water often deteriorates. In order to eliminate these drawbacks, wastewater is introduced into a decarbonation process to remove carbonic substances from the wastewater, add a calcium agent and/or an alkaline agent, and then pass through a sand filtration tank to remove 8Eli from the wastewater. After that, the solution was passed through a dephosphorization tank filled with dephosphorization material. However, this method has the disadvantage that not only the process is complicated, but also a large amount of acid is required for decarboxylation.

On the other hand, as a method for removing ssy from wastewater, a moving bed 1 filtration method is known in which a part of the ssy material is constantly circulated and regenerated, but this method cannot remove ti 17 There is also the disadvantage that it is difficult to sufficiently regenerate contaminated filter media, and therefore, the transport of the filter media becomes partially impossible, resulting in clogging.

[Structure of the invention]

The present invention provides a method for removing 8S and phosphorus from wastewater by adding a calcium agent and/or an alkaline agent to the wastewater and bringing it into contact with a filter medium having a postcutaneous phosphorus removal ability. The present inventor has proposed a method for removing 8S and phosphorus from wastewater, which comprises extracting 8S and phosphorus from sewage, adding acid or alkali to the extracted material, and transferring the recycled material to the upper part of the filter layer. As a result of repeated studies to solve all the problems of the above-mentioned conventional techniques, the catalytic dephosphorization method and the moving bed filtration method were developed. Organically bound SS in liquid
and a method for efficiently removing phosphorus.

Next, an embodiment of the present invention will be explained based on FIG.

In Fig. 1, numeral 1 is a wastewater introduction pipe, 2 is a calcium agent and/or alkali agent introduction pipe, 3 is an in-pipe mixer, 4 is a reaction tank, 5 is a distribution amount, 6 is a dephosphorization material layer, and 7 is air. Blowing pipe, 8 is rR<or alkali] introduction pipe, 9 is transfer pipe, 10
11 is a regeneration tank, 12 is a distribution umbrella, 13 is a washing water discharge pipe, 14 is a treated water discharge pipe, and 15 is a washing water jet.

Calcium agent and/or alkali agent inlet tube 2 Ecalcicum agent and/or alkali agent were completely injected into the wastewater supplied through sewage inlet tube 1, and the dephosphorization material mixed in pipe mixer 5 was completely filled. Introduced into reaction tank 4. The dirt 1 water introduced into the reaction tank is distributed at a distribution rate 5, flows upward through the dephosphorization material layer to remove phosphorus, and then passes through the post-treated water discharge pipe 1.
It is discharged from 5. On the other hand, by blowing air into the lower part of the transfer pipe 9, a part of the E-dephosphorization material is transferred upward in the transfer pipe. In addition, by injecting 8 ecuic acid into the lower part of the transfer tube, the citric acid is mixed with the air. The contaminants that are introduced into the transfer pipe 9 from the lower part of the reaction tank 4 and adhered to the dephosphorizing material are peeled off by the agitation action of the air, and the calcium carbonate that has adhered as a contaminant is removed by the acidic acid. The generated carbonic acid is degassed by air and transported upward through the transfer pipe together with the dephosphorizing filter medium that is being regenerated. The decomposed material transferred upward is discharged into the upper regeneration tank 11, where it is washed by treated water flowing into the lower part of the regeneration tank, and is distributed over the distribution volume 12 in countercurrent to the treated water. While being distributed, it is returned onto the dephosphorization material layer. The cooled air and degassed air are separated in the regeneration tank and the cooled gas components are discharged to the outside of the air relief pipe 10.
3 times are discharged. On the other hand, the treated water is discharged to the outside of the system through the treated water discharge pipe 14.

Figure 2 shows an example of a device in which dephosphorization material is placed outside the reaction tank and regenerated while being transferred to the next transfer pipe.
Descriptions related to figures have the same meaning as the following symbols. In addition, the second
In the example shown in the figure, air and the like separated from the dephosphorized r material are discharged from the upper part of the regeneration tank 11 to the outside of the system.

Next, other embodiments of the present invention will be described based on the $5 figure. In FIG. 3, the same symbols as in FIG. 1 have the same meanings, 16 is the r material transfer pump, 17 is the pressure water pipe,
19 indicates a stirrer, and 19 indicates a tube for introducing an alkali or organic solvent.

In the apparatus shown in FIG. 5, part of the dephosphorizing material is transferred and regenerated by a transfer pipe 9 provided outside the reaction tank 4, but the dephosphorizing material is transferred by a transfer pump 16. It is. In the example shown in FIG. 3, in order to smoothly transfer the lower filter medium, it is provided in the pressure water pipe 17 for causing a part of the treated water to flow into the r-material suction section.

In order to efficiently regenerate and clean the dephosphorizing material, a stirrer 18 is provided in the regeneration tank 11.

In addition, if the dephosphorization material has severe organic contamination, the acid inlet pipe 8
Even if you inject organic rRt, it will not work, but if this error occurs,
19t inlet pipe for injecting all alkali or organic solvent
- on the transfer tube 9;

As the dephosphorizing material, phosphate rock, bone charcoal, light furnace slag, light burnt magnesia, etc. can be used, and the particle size of the filtering material (dephosphorizing material 2 is preferably α5I+I11 to 2-0wm811).

Gypsum, calcium chloride and/or slaked lime can be used as the calcium agent to be mixed with the inflowing sewage, and slaked lime, caustic soda and/or aqueous magnesium can be used as the alkaline agent.

If the dephosphorizing agent is mainly contaminated with calcium carbonate, it is preferable to use an acid such as #1 acid, sulfuric acid, or an organic acid as a regenerating agent. Preferably, organic acids, alkalis or organic solvents are used as agents.

The air blown into the lower part of the transfer pipe 9 depends on the height of the transfer pipe, but about 5% 2 kg 7 cm of pressurized air is blown into the lower part of the transfer pipe 9 in an amount of about 1 to 5 times the amount of 1 liter of treated water, and the regeneration tower is The amount of treated water for washing to 11 is 5 to 5 of the total amount of treated water.
If the amount is about 15%, it will be L.

The amount of acid injected into the transfer tube is determined when the liquid in the transfer tube has a pH of 5 to
The amount of alkali is such that the pH in the transfer tube is 10 to 6.
It is best to add in an amount of about 12.

Example 1 A device as shown in Fig. 1 having a column height of 2500 m and an inner diameter of 380 m was filled with (L5 to 18 m of phosphate rock to a thickness of 800 mW), pH of 5 to ?, o, and Ca-containing elements of 60 to 80 mW.
Water was passed through at a rate of t-120 m3/day of secondary treated sewage water adjusted to /l.

A 19 φ air lift pipe is installed in the tank, total air 1.5J
Blowing at a rate of /min (lifting sand 86111!/, hours) +
I put in 1. At the same time, 1% hydrochloric acid was injected into the air lift pipe, and a regeneration tower (capacity 1 t) was installed at the top of the air lift pipe.
) has a pH of 4.5.

The processing results are shown in '9r Hori-i. As a comparative example, Table 1 also shows the results obtained without injection of hydrochloric acid.

In addition, the water quality of the secondary sewage treatment water has a phosphorus content of 1 to 2 m
W/L SM-alkalinity 100 mW/AsS
B 5-7 mf/l, pH & 5-7.0.

Table 1 As shown in Table 1, the method of the present invention maintains the phosphorus concentration of treated water at a stable low level for a long period of time.
However, in the comparative example, the quality of the treated water gradually deteriorated. In addition, in the comparative example, a portion of the dephosphorization material layer solidified after 6 months, and an increase in filtration resistance was observed.

Example 2 The same equipment used in Example 1 was used to treat organic wastewater. Inside the air lift tube, there is 1° of NaOHt-
The amount added was adjusted until the pH reached 10-11. On the other hand, as a comparative example, a test was conducted without injecting NaOH1r.

The complete results are shown in Table-2.

Table-2 Raw water quality Nilin 5-4mf74M-Alkalinity 50mf
/1s g 1o mW/l, chromaticity 50'pa6
．． 5-7.0 As shown in Figure 2, the method of the present invention can maintain the quality of treated water stably for a long period of time, but in the comparative example, the phosphorus concentration in the treated water gradually increases. In example 5, the filter medium turned brown from the edge of the blade, and part of the layer where the gills of the edge of the blade were removed became clogged, resulting in an increase in filtration resistance.

〔Effect of the invention〕

According to the present invention, since the dephosphorization material can be constantly regenerated, there is no contamination of the dephosphorization material, and therefore, SS and phosphorus can be completely removed stably and efficiently for a long period of time in one reaction tank.

[Brief explanation of the drawing]

1, 2 and 3 show schematic flow diagrams for explaining the entire method of the invention. 1. Sewage introduction pipe, 2. Calcium agent and/or alkali agent introduction pipe, 3. In-pipe mixer, 4. Reaction tank, 5.
・Distribution umbrella, 6.・Dephosphorization material layer, 7.・Air blowing pipe, 8.
・Acid or alkali introduction pipe, 9. Transfer pipe, 10. Air relief tube, 11. Regeneration tank, 12. Distribution umbrella, 13. Washing water discharge pipe, 14. Treated water discharge pipe, 15゛. . Washing water spout, 16...F material transfer pump, 17...pressure water pipe, 18...stirrer, 19...alkali or organic solvent introduction pipe

Claims (1)

[Claims] 1. After adding a calcium agent and/or an alkaline agent to wastewater, the S in the wastewater is removed by contacting it with a filter medium having phosphorus removal ability.
A method for removing S and phosphorus from waste water, which is characterized by extracting a part of the filter material from the lower part of the filter material layer, adding acid or alkali to the extracted filter material to regenerate it, and transferring it to the upper part of the filter material layer. A method for removing SS and phosphorus. 2. SS in wastewater according to claim 1, which transfers the filter material extracted by blowing air into the transfer pipe.
and a method for removing phosphorus.