KR101616276B1 - Sewage sludge treament complex solubilizing system - Google Patents

Abstract

The present invention relates to a system reducing and solubilizing sewage sludge. More particularly, a sewage sludge complex treatment solubilization system of the present invention comprises: a ball mill crusher in which sludge is crushed by shear friction and heat generated among balls being mixed; an alkali injection device which chemically decomposes cellular walls of microbes in the sludge; an electrolysis device which performs solid-liquid separation and solubilization using electrolysis; and a dehydration device. The sewage sludge complex treatment solubilization system compensates shortcomings in each component, for example: removing a clogging problem of the ball-mill crusher, thereby reducing driving costs; removing non-biodegradable substances generated from injecting alkaline chemicals at a precipitation tank; simplifying an electrolysis device, thereby having convenience when driving the system; and enhancing treatment efficiency with respect to an increase in pH by alkaline chemicals added from a pretreatment stage. Therefore, the sewage sludge complex treatment solubilization system can reduce costs of treating sewage sludge while enhancing treatment efficiency.

Description

[0001] Sewage sludge complex treatment solubilizing system [0002]

The present invention relates to a system for reducing and solubilizing sewage sludge, and more particularly, to a system for reducing and solubilizing sewage sludge, including a ball mill crushing device for crushing sludge by heat and a shear frictional force generated between stirred balls, an alkali input for chemically decomposing cell walls of microorganisms in sludge, The present invention relates to a sewage sludge combined treatment and solubilization system composed of an electrolytic apparatus and a dewatering apparatus for solid-liquid separation and solubilization using decomposition.

At present, the amount of sewage sludge is increasing, and the marine sludge generated is banned from 2012 due to the entry into the London Convention. However, landfill, incineration, recycling, There is a problem of recycling treatment at a high cost.

Techniques for solubilising general sewage sludge are largely biological treatment techniques using specific microorganisms or enzymes, physical treatment techniques using ultrasonic waves or hydrodynamic cavitation, thermal hydrolysis and ball milling, chemical treatments using ozone or alkaline chemicals A combined treatment technique combining two or more of the treatment techniques, and an electric treatment technique using electrolysis.

Among the physical treatment techniques, the ball mill treatment technique is a method of introducing sludge into a crushing chamber filled with ball rotating at high speed and crushing sludge by shear frictional force and heat generated between agitated metal balls. Generally, It is safe for foreign materials, but in the process of separating the steel ball from the sludge liquid, clogging occurs in the separation facility, so it is necessary to install several units in order to treat a certain flow rate and it is necessary to perform inspection every time. have.

The alkali treatment technique of the chemical treatment technique is performed by the chemical decomposition of the microbial cell walls in the sludge. As the concentration of the alkali agent and the contact time are increased, the solubilization efficiency is increased, and thereafter, And in the case of combining heat treatment to increase the solubilization efficiency, the treatment temperature is low and the economical efficiency is high, but it has a problem of generating odor and detergent.

The electrolytic treatment technique is a method of treating wastewater by electrolytic reaction by supplying electrical energy to wastewater mixed with inorganic, organic, and electrolyte as a principle of battery chemical reaction, and is a method of electrolytic flocculation, It is a method to remove contaminants by action of ignition, electrostatic attraction, chemical conversion, chemical precipitation and so on.

When the sludge is solubilized, the sludge is solubilized by electrolytic concentration unit and electrolytic unit when the sludge is precipitated or separated by flocculation, electrooxidation or electro flotation reaction. There is a problem that the complex structure and the cost due to solubilization of the sludge are high.

Meanwhile, the conventional technology of the complex treatment technology of the present invention is Korean Patent No. 10-066196 (Mar. 1, 2007), which relates to a method of reducing sewage sludge using mechanical pretreatment, aerobic digestion, metal catalyst and ozone oxidation, The present invention relates to an aerobic digestion technique following the solubilization of sewage sludge by mechanical pretreatment, and a method for reducing sewage sludge with high efficiency using a metal catalyst and ozone oxidation.

The mechanical pre-treatment of the above conventional complex treatment technique also uses a ball mill crushing device, but has the same problems as the above-mentioned ball mill crushing device and has a complicated structure such as aerobic digestion, metal catalyst and ozone treatment, and high cost.

Korean Patent No. 10-066196 (2007.01.09.)

The present invention relates to a conventional method for solubilizing sewage sludge as described above, a clogging phenomenon caused by sludge in a ball milling apparatus, a problem caused by generation of a refractory substance of an alkali chemical, a problem caused by a complicated structure of electrolysis, The purpose of this study is to solve the problem of high cost due to sludge treatment.

In order to solve the above problems and to achieve the object, the sewage sludge combined treatment solubilizing system of the present invention comprises

A ball mill crushing device for crushing the sludge generated from the lower and wastewater treatment processes by the shear frictional force and heat generated between the agitated metal balls and driven in a reverse direction for a predetermined time by alternate control to clean the ball and screen net;

Alkali injection for chemically decomposing the sludge from the ball milling apparatus;

A sedimentation tank for precipitating the alkali-impregnated sludge;

An electrolytic apparatus for ultimately reducing the sludge from the settling tank;

And a dewatering device for dewatering the reduced sludge in the electrolysis device to produce a dewatered cake.

The ball mill crushing device has a cylindrical shape and is installed horizontally or vertically. The discharge port through which the crushed sludge is discharged has a lattice-shaped screen net smaller than the size of the ball filled in the crushing device, thereby preventing clogging.

The inside of the ball mill shredding apparatus is equipped with a stirrer of a rotating plate and is filled with 55 to 85% of the volume of the shredding apparatus with a glass ball or a metal ball having a particle diameter of 4 to 9 mm. The rotating speed of the stirring equipment is 6 to 22 m / s. < / RTI >

The alkali in the alkali injection uses a monovalent alkali rather than a divalent alkali which is partially dissolved.

The sludge is precipitated in the settling tank, and the sewage, which is the liquid on the upper part of the solid-liquid separated sludge, is refluxed to be reintroduced into the bioreactor.

The electrolytic apparatus is characterized in that it decomposes, coalesces, and precipitates radicals in accordance with an oxidation-reduction reaction by electrolysis, thereby destroying the cell membrane by an electrolytic flocculation tank in which sludge is sedimented or float- And a solubilization tank in which the water content, the amount of generated water, and the odor are reduced, are used.

The sludge solid-liquid separated from the electrolytic floatation concentrator is injected into the solubilization tank, and the separated sludge is returned to the bioreactor.

Wherein the electrolytic flocculation is carried out for 6 to 9 minutes at a current of 6 to 9 minutes and the gravitational force is 4 to 6 mm and the current for solubilization is applied within 25 to 60 minutes.

As described above, the solubilization system for sewage sludge combined treatment according to the present invention eliminates clogging of the ball mill crushing apparatus, thereby reducing operating costs, eliminating substances from the sedimentation tank that are generated by charging alkaline chemicals, Simplification and convenience of operation, and the treatment efficiency is also increased by the increase of the pH by the alkaline medicine which is the pretreatment step. Thus, the sewage sludge treatment cost can be reduced and the treatment efficiency can be improved.

1 is a flow chart of a sewage sludge combined treatment solubilization system according to an embodiment of the present invention.
2 is a perspective view of a ball milling apparatus according to an embodiment of the present invention.
3 is a flow chart of an electrolysis apparatus according to an embodiment of the present invention.

The present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like elements, and in which: FIG. Also, the terms defined in the present specification and claims should not be construed as limiting, but may be changed according to the intention or custom of the operator, and interpreted in terms of meaning and concept consistent with the technical idea of the present invention.

In one aspect of the present invention,

2 is a perspective view of a ball milling apparatus according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of an electrolysis apparatus according to an embodiment of the present invention. Referring to FIG. 1, Fig.

As shown in FIG. 1, the sludge combined treatment and disinfection system of the sewage sludge complex treatment disintegrates the sludge produced in the sludge treatment process by the shear frictional force and the heat generated between the stirred metal balls. When the sewage sludge liquid passes through the body, Solid matter is broken down by iron globules, and some of the microbial cells are degraded. A ball mill crushing device driven in a reverse direction for a predetermined time by alternate control to clean the ball and screen net; Alkali injection for chemically decomposing the sludge from the ball milling apparatus; A sedimentation tank for precipitating the alkali-impregnated sludge; An electrolytic apparatus for ultimately reducing the sludge from the settling tank; And a dewatering device for dewatering the reduced sludge in the electrolysis device to produce a dewatered cake.

As shown in FIG. 2, the ball mill crushing device has a cylindrical shape, and is installed horizontally or vertically. The discharge port through which the crushed sludge is discharged is provided with a grid screen network having a size smaller than that of the ball filled in the crushing device. The inside of the ball mill crushing apparatus is provided with a stirring apparatus for stirring the rotating plate and is filled with a glass ball or a metal ball having a particle diameter of 4 to 9 mm at 55 to 85% of the volume of the crushing apparatus, Is operated at 6 to 22 m / s.

The stirrer of the ball mill shredding apparatus can be used as a generally used motor, and the ball mill shredding time is 8 to 12 minutes, and it is driven in the reverse direction for 1 to 2 minutes through alternate control to have a cleaning function.

Meanwhile, before the ball milling apparatus is operated, liquid iron salts acting as an oxidizing agent and a flocculating agent can be injected to increase the efficiency. The liquid iron salt can be prepared by a method in which a single cathode plate composed of iron and two cathode plates made of titanium are electrochemically oxidized Increase efficiency by injecting sludge in salt-containing state.

In the alkali injection, the alkali uses monovalent alkali rather than the bivalent alkali which is partially dissolved, and the sewage sludge into which the alkali drug is injected sedimentates the sludge in the settling tank, and the sewage which is the liquid on the upper part of the separated sludge, Is refluxed.

As shown in FIG. 3, the electrolytic apparatus is characterized in that it decomposes, coalesces, and precipitates radicals according to the oxidation and reduction reaction by electrolysis, and accordingly, the electrolytic float thickener and electricity The electrolytic reduction and weighing apparatus composed of two stages, that is, a solubilization tank in which the cell membrane is broken by decomposition to reduce the water content, the amount of generation and the odor, is used, and the sludge solid-liquid separated from the electrolytic floatation tank is injected into the solubilization tank, The current is applied to the bioreactor for 6 to 21 minutes, the gravitational force is 4 to 6 mm, and the current for solubilization is applied within 25 to 60 minutes.

Hereinafter, an experimental example on an electrolytic part according to the present invention will be described. However, these experimental examples are provided to aid understanding of the present invention, and the contents and scope of the present invention are not limited.

( Experimental Example )

The electrolytic float for the solid-liquid separation was carried out using the transport sludge collected at the SODA water recovery center, pH - 6.4 to 6.9, TS (mg / L) - 16,300 to 19,575, VS (mg / L) - 12,425 to 15,375, TCODcr (mg / L) - 15,309 ~ 17,885, SCODcr (mg / L) - 77 ~ 132, respectively. Concentration according to current application time and concentration according to electrode interval were performed.

The concentration of the sewage sludge according to the current application time at an electrode interval of 5 mm and a current density of 6.3 mA / cm 2 is shown in Table 1 below.

As shown in Table 1, the solid-liquid separation of the sewage sludge began to be gradually separated after 6 minutes, and the concentration efficiency up to 2 L for about 10 minutes was about 66%, which was not significantly increased after 20 minutes.

Table 2 shows the concentration of sewage sludge according to the electrode interval (4 to 6 mm) at a current density of 6.25 mA / cm 2 and a current application time of 20 minutes.

As shown in Table 2, as the electrode interval becomes narrower, the resistance becomes smaller, which is advantageous from the energy saving point of view, but does not greatly affect the concentration efficiency of the sewage sludge.

 As described above, the solubilization system for sewage sludge combined treatment according to the present invention eliminates clogging of the ball mill crushing apparatus, thereby reducing operating costs, eliminating substances from the sedimentation tank that are generated by charging alkaline chemicals, It has advantages in simplicity and driving, and it improves the treatment efficiency by increasing the pH by the alkaline medicine which is the pretreatment stage. Thus, it is possible to reduce sewage sludge disposal cost and treatment efficiency.

While the present invention has been described in connection with certain exemplary embodiments and drawings, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Various modifications and variations are possible.

10: Ball mill crusher 20: Alkali injection
12: body 30: settling tank
14: stirrer 40: electrolytic device
15: Ball 42: Electrolytic Emulsion Enrichment Tank
17: Screen net 44: Solubilization tank
18: electric motor 50: dehydrator

Claims (8)

A system for solubilising sewage sludge, comprising:
The solubilization system
A ball mill crushing device for crushing the sludge generated from the lower and wastewater treatment processes by the shear frictional force and heat generated between the agitated metal balls and driven in a reverse direction for a predetermined time by alternate control to clean the ball and screen net;
Alkali injection for chemically decomposing the sludge from the ball milling apparatus;
A sedimentation tank for precipitating the alkali-impregnated sludge;
An electrolytic apparatus for ultimately reducing the sludge from the settling tank; And
And a dewatering device for dewatering the reduced sludge in the electrolysis device to produce a dewatered cake,
Wherein the liquid iron salt is in the form of a liquid iron salt contained in the liquid iron salt by the electrooxidation method and the one of the positive electrode plate made of iron and the two negative plates made of titanium is injected into the ball mill, Sludge,
The ball mill crushing device has a cylindrical shape and is installed horizontally or vertically. The discharge port through which the crushed sludge is discharged is provided with a lattice-shaped screen net smaller than the size of the ball filled in the crushing device, The cleaning time is 8 ~ 12 minutes and it is operated in reverse direction for 1 ~ 2 minutes by alternate control,
The inside of the ball mill is charged with 55 to 85% of the volume of the crusher by a glass ball or a metal ball having a particle diameter of 4 to 9 mm, 22 m / s,
In the alkali injection, the alkali uses a monovalent alkali rather than a partially soluble alkali,
The sludge is precipitated in the settling tank, and the sewage, which is the liquid on the upper part of the solid-liquid separated sludge, is returned to the bioreactor,
The electrolytic apparatus is characterized in that it decomposes, coalesces, and precipitates radicals in accordance with an oxidation-reduction reaction by electrolysis, thereby destroying the cell membrane by an electrolytic flocculation tank in which sludge is sedimented or float- And a solubilization tank in which the water content, the amount of generated water, and the odor are reduced,
The sludge solid-liquid separated from the electrolytic float concentration tank is injected into the solubilization tank, and the sewage separated from the sludge is returned to the bioreactor,
Wherein the electric current is applied to the electrolytic float concentration tank for 6 to 21 minutes, the interval between the electrodes is set to 4 to 6 mm, and the current for solubilization is applied for 25 to 60 minutes or less. delete delete delete delete delete delete delete

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