JPH105792A - Leaching water treating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a treating process and device constitution and to improve the removal rate of suspended material, COD components and manganese. SOLUTION: A flocculation treating device 12 comprises a flocculating and intimately mixing vessel 19 provided with a flocculating agent injecting pipe 13 and a flocculation filter vessel 20 internally provided with a membrane module 27 consisting of ceramic membrane elements. The COD components and manganese can be decreased and the suspended materials, colibacilli, etc., are nearly surely removed by these ceramic membrane elements and, therefore, there is no need for a flocculating vessel (slow speed agitating vessel), sand filter vessel and disinfecting vessel which are heretofore disposed. The flocculation filter vessel as a vessel for separating solid from liquid is more compact than a conventional flocculation settling vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leachate treatment facility for treating leachate at a final disposal site for general waste and industrial waste.

[0002]

2. Description of the Related Art Leachate at final disposal sites for general and industrial wastes is treated according to the flow shown in FIG.

[0003] In other words, raw leachate is introduced into the biological treatment apparatus 1 to biologically remove nitrogen and BOD substances in the raw water, and biologically treated water 2 flowing out of the apparatus 1 is introduced into the coagulation treatment apparatus 3. Then, suspended substances (SS) such as microorganisms in the biologically treated water are agglomerated with a flocculant in a mixing tank (rapid stirring tank) 3A, and the generated flocs are grown and grown in a flocculating tank (slow stirring tank) 3B. The floc is settled by gravity in the coagulating sedimentation tank 3C.

Thereafter, the coagulated water 4 as supernatant water in the coagulation sedimentation tank 3C is introduced into the sand filtration tank 5, and the remaining suspended substances such as fine flocs are collected by the sand filtration layer and flown out of the tank 5. The sand filtration water 6 is introduced into the activated carbon adsorption tower 7,
The D component and chromaticity are adsorbed and removed by activated carbon, and the activated carbon treated water 8 flowing out of the tower 7 is introduced into a disinfection tank 9 for disinfection and discharged as final treated water 10.

[0005]

However, in the above-mentioned conventional processing method, the processing steps and the equipment configuration are complicated, and in particular, the coagulation and sedimentation tank requires a large installation space due to a large required capacity, and the amount of chemical injection is large. There is a problem that also increases.

Further, there is a problem that suspended matter cannot be completely removed by sand filtration, and the removal rates of COD components and manganese are low. An object of the present invention is to solve the above-mentioned problems, and to provide a leachate treatment facility capable of simplifying a treatment process and an apparatus configuration and improving a removal rate of suspended matter, COD components, and manganese. .

[0007]

Means for Solving the Problems To solve the above problems, a leachate treatment facility of the present invention comprises a biological treatment apparatus, a coagulation treatment apparatus and an activated carbon leachate at a final disposal site for general waste and industrial waste. In the leachate treatment equipment for sequentially introducing and treating into an adsorption tower, the coagulation treatment device is constituted by a coagulation mixing tank provided with a coagulant addition means, and a coagulation filtration tank provided with a ceramic membrane therein. is there.

According to the above-mentioned structure, biologically treated water flowing out of the biological treatment device is introduced into the coagulation mixing tank, and a flocculant is added by the coagulant adding means to coagulate suspended substances such as microorganisms in the biologically treated water. The coagulant mixed water containing the generated floc is introduced into the coagulation filtration tank, and is subjected to solid-liquid separation by a ceramic membrane.

At this time, since fine particles can be separated by a ceramic membrane, suspended substances such as fine flocs,
Escherichia coli group and general bacteria can be almost certainly removed, and COD components and manganese can be reduced as compared with the conventional case.

For this reason, the conventional flocculation tank (slow stirring tank), sand filtration tank and disinfection tank are not required, and the flocculation filtration tank as the solid-liquid separation tank is more compact than the conventional flocculation and sedimentation tank. In addition, the device configuration is simplified.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a leachate treatment facility for treating leachate at a final disposal site for general waste and industrial waste includes a biological treatment device 11, a coagulation treatment device 12, and an activated carbon adsorption tower 13.

The biological treatment apparatus 11 is of a contact aeration type in which a filling material 15 is filled in a tank 14 and an air diffuser 16 is provided below the filling material 15. A raw water supply pipe 17 for supplying raw water, and a biologically treated water supply pipe 18 for sending biologically treated water treated in the tank to the coagulation treatment device 12
And are open.

The coagulation treatment device 12 includes a mixing tank 19, a coagulation filtration tank 20, and a neutralization tank 21. Mixing tank 19
, A biologically treated water supply pipe 18 led from the biological treatment apparatus 11, a pH adjuster injection pipe 22 for injecting a pH adjuster such as sulfuric acid or hydrochloric acid, and an aggregating agent such as ferric chloride or PAC. A coagulant injection pipe 23 and a coagulant mixed water supply pipe 24 for feeding coagulant mixed water mixed with coagulant in the tank to the coagulation filtration tank 20 are opened at the upper part of the tank, and a stirring device 25 and a pH meter 26 are provided.
Are provided inside.

In the coagulation filtration tank 20, a coagulant mixed water supply pipe 24 led from the coagulation mixing tank 19 is opened at the top of the tank, and a plurality of membrane modules 27 are stacked inside. The membrane module 27 is formed by connecting a plurality of external pressure type tubular ceramic membrane elements (nominal hole diameter of 0.1 μm or less) with a header, and an air diffuser 28 is provided below the membrane module 27. A membrane filtration water pipe 29 communicating with the header is led to the neutralization tank 21, and a pump 29a
By applying a suction pressure, the membrane surface is washed by a bubble flow from the air diffuser 28 while solid-liquid separation is performed by the membrane element.

In the neutralization tank 21, a membrane filtration water pipe 29 led from the coagulation filtration tank 20 and a pH adjusting agent injection pipe 30 for injecting a pH adjusting agent such as caustic soda are opened at the upper part, and a stirring device 31 is provided. A coagulation water supply pipe 32 that is provided inside and sends coagulation water obtained by adding a pH adjuster to the membrane filtered water flowing into the tank to the activated carbon adsorption tower 13 is open at the bottom of the tank. The neutralization tank 21 is also provided with a backwash water pipe 33 for sending the membrane filtered water flowing into the tank to the membrane filtered water pipe 28 as backwash water.
32a and 33a are pumps.

In the activated carbon adsorption tower 13, a flocculated water supply pipe 32 led from the neutralization tank 21 is opened at the upper part.
4 is filled inside, and a treated water pipe 35 is opened below the activated carbon 34 layer.

The operation of the above configuration will be described below. Leachate raw water is supplied from the raw water supply pipe 17 into the tank 14 of the biological treatment apparatus 11, and while the filler 15 is kept immersed in the raw water 36 in the tank, aeration is performed by the air diffuser 16 to perform filling. The raw water 36 is purified by the aerobic bacteria attached to the material 15, and the purified biologically treated water is sent to the mixing tank 19 of the coagulation treatment device 12 through the biologically treated water supply pipe 18.

While the biologically treated water 37 flowing into the mixing tank 19 is rapidly stirred by the stirrer 25, a pH adjuster such as sulfuric acid or hydrochloric acid is injected from the pH adjuster injection pipe 23 and the coagulant injection pipe 24 is injected. A coagulant such as ferric chloride or PAC is injected to thereby coagulate suspended substances contained in the biologically treated water 37, and coagulant mixed water containing the generated flocs is coagulated through the coagulant mixed water supply pipe 22. Filtration tank 2
Send to 0.

The coagulant mixed water 38 flowing into the coagulation filtration tank 20 is separated into solid and liquid by each membrane module 27, the floc is left in the tank, and the membrane filtration water permeating the membrane surface is passed through the membrane filtration water pipe 29. Send to Japanese tank 21.

While the membrane filtered water 39 flowing into the neutralization tank 21 is stirred by the stirrer 31, a pH adjusting agent such as caustic soda is injected from the pH adjusting agent injection pipe 30 to coagulate the neutralized water. Coagulation treatment water supply pipe 32 as treatment water
To the activated carbon adsorption tower 13.

In the activated carbon adsorption tower 13, the coagulated water 40 that has flowed in is passed downward, so that the
The OD component and the chromaticity are removed by adsorption, and the activated carbon treated water purified thereby is discharged through the treated water pipe 35.

According to the above-described leachate treatment equipment, since fine particles can be separated by the ceramic membrane element, suspended substances such as minute flocs can be removed to 1 mg / L or less, and coliforms and general bacteria can be almost completely eliminated. It can be removed, and the COD component and manganese can be reduced as compared with the conventional case.

For this reason, a flocculation tank (slow stirring tank) for growing flocs as in the prior art is not required, and the flocculation and filtration tank 20 itself is more compact than the conventional flocculation and sedimentation tank. In this case, since the conventional sand filtration tank and disinfection tank are not required, the apparatus configuration is simplified.

Table 1 below shows the quality of the activated carbon treated water obtained by the above-described method of the present invention and the conventional method.
The leachate raw water has a COD concentration of 90 mg / L and a Mn concentration of 1
It was 0 mg / L.

[0025]

[Table 1]

[0026]

As described above, according to the present invention, by incorporating a coagulation filtration tank provided with a ceramic membrane therein into a leachate treatment system, the COD component can be reduced while having a simpler treatment process and apparatus configuration than before. , Manganese, suspended solids,
The number of coliforms and the like can be reduced as compared with the past, and the installation space can be reduced, labor and energy can be saved, and costs can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of a leachate treatment facility according to one embodiment of the present invention.

FIG. 2 is a flowchart illustrating a conventional leachate treatment method.

[Explanation of symbols]

 11 Biological treatment equipment 12 Coagulation treatment equipment 13 Activated carbon adsorption tower 19 Mixing tank 20 Coagulation filtration tank 24 Coagulant injection pipe 27 Membrane module

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication B01D 71/02 B01D 71/02 C02F 1/44 C02F 1/44 K 3/06 ZAB 3/06 ZAB

Claims (2)

[Claims] 1. A leachate treatment facility for sequentially introducing leachate at a final disposal site of general waste or industrial waste into a biological treatment device, a coagulation treatment device, and an activated carbon adsorption tower for treatment, wherein the coagulation treatment device is And a coagulation mixing tank provided with a coagulant adding means, and a coagulation filtration tank provided with a ceramic membrane therein. 2. The leachate treatment equipment according to claim 1, wherein the pore diameter of the ceramic membrane is 0.1 μm or less.