KR100933055B1 - Odor gas adsorbent manufacturing method using purified sludge and odor gas adsorbent manufactured by this method - Google Patents

Abstract

The present invention relates to a method for preparing malodorous gas adsorbent using purified sludge, and to a malodorous gas adsorbent prepared by the method, for the purpose of manufacturing purified wastewater sludge for removal of malodors such as ammonia through a metal salt-based impregnation reagent. do.

In the method for preparing malodorous gas adsorbent using purified sludge according to the present invention, 5 to 20 parts by weight of a metal salt-based additive is mixed and immersed for 18 to 22 hours with respect to 100 parts by weight of purified water sludge. A first step of attaching to the sludge; A second step of drying the solid material (solid material such as powder activated carbon, SiO 2, alumina oxide (Al 2 O 3), etc.) and the impregnated aqueous solution produced in the first step at 100 to 150 ° C .; A third step of grinding the adsorbent dried by the second step to 10 mesh or less; The fourth step of coating the surface of the adsorbent pulverized by the third step with water glass.

Description

Method for preparing malodorous gas adsorbent using purified sludge and malodorous gas adsorbent manufactured by this method

The present invention relates to a malodorous gas adsorbent, and more particularly, to a surface of a powder activated carbon containing a purified water sludge, by dispersing flocculation of purified sludge agglomerated by agglomerated polymer by mixing a metal salt-based impregnated reagent with purified sludge. And a method for preparing a malodorous gas adsorbent using purified sludge capable of increasing chemical activity and improving adsorption capacity by depositing a metal salt-based impregnation reagent on an inner wall of a pore, and a malodorous gas adsorbent prepared by the method.

Unlike sewage sludge, sludge produced in a water purification plant has a low content of harmful substances and a clay-like property, and research for recycling has been conducted in various aspects, and as an example, a method of using it as a building brick has been suggested.

The chemical components of the water treatment plant sludge are mostly composed of silica powder (SiO 2) and alumina (Al 2 O 3), and other trace metals have been reported. Due to the chemical composition, techniques for recycling the purified sludge into an adsorbent that can be used to remove and remove various harmful heavy metals have been proposed.

However, the adsorbent using purified water sludge according to the prior art has the following problems.

As a method for producing purified sludge as an adsorbent, a hydrothermal synthesis method is generally used. In this case, since the adsorbent is manufactured depending on high temperature heat of 100 degrees Celsius or more, the manufacturing cost becomes expensive and functional as the energy consumption increases. There is a problem in that the adsorption capacity is limited to physical adsorption.

The present invention is to solve the above problems, by adsorbing a specific metal salt on the surface and the inner wall of the pore of the powder activated carbon contained in the purified water sludge which is a waste generated in the water purification plant by using low energy to increase the chemical activity and adsorption capacity It is an object of the present invention to provide a method for preparing malodorous gas adsorbents using purified water sludge capable of selectively adsorbing malodorous gases according to metal salts to be deposited, and the malodorous gas adsorbents produced by the method.

In the manufacturing method of odor gas adsorbent using purified water sludge according to the present invention for achieving the object as described above, by mixing and immersing the metal salt-based impregnated reagent in the purified water sludge so that the metal salt-based impregnated reagent is attached to the purified water sludge Making a step; And drying the impregnated aqueous solution with the solid material produced in the first step (solid material such as powder activated carbon, SiO 2, alumina oxide (Al 2 O 3)).

The invention is characterized in that it further comprises the step of coating the surface of the adsorbent.

According to the method for preparing malodorous gas adsorbent using purified sludge and the malodorous gas adsorbent prepared by the method, the wastewater purified sludge may be recycled to the adsorbent to reduce the cost of waste treatment, Through this, the adsorbent having higher adsorption efficiency than general activated carbon is manufactured at low temperature without using a separate heat source, thereby reducing the manufacturing cost of the adsorbent and increasing energy efficiency.

In particular, by producing a low-cost, high-efficiency adsorbent, it can be effectively used to remove odors generated in sewage treatment plants, food waste treatment plants, sewage sludge recycling plants, livestock farms such as pig farms and organic fertilizer plants.

The present invention may be variously modified and may take various forms according to the type of malodorous gas and the metal salt-based impregnation reagent, and the detailed description of the present invention has been described only with respect to the specific embodiments accordingly. However, it should be understood that the present invention is not limited to the specific forms mentioned in the detailed description, but rather those skilled in the art can make many changes and modifications to the present invention without departing from the spirit and scope of the appended claims. I can understand. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

Before demonstrating the manufacturing method of the malodorous gas adsorbent using the purified sludge by this invention, a purified sludge is demonstrated.

<Table 1> shows the chemical composition of the purified sludge, and the chemical composition of the purified sludge may be different depending on the water treatment method, the location of the purified water plant, and the season.

Table 1. Chemical Composition of Purified Sludge (Seoul Guui Water Purification Plant; December 2008)

Analytical Ingredients F Na ₂ O MgO Al ₂ O ₃ SiO ₂ P ₂ O ₅ SO ₃ Cl K ₂ O CaO Fe ₂ O ₃ Content (wt.%) 0.57 0.3 0.85 44 36.4 2.3 2.86 1.14 1.44 2.22 6.5

The water content of purified water sludge varies according to the location and seasonality. The water purification plant under the Seoul Waterworks Headquarters is 65% to 75%, and the particle specific surface area of purified water sludge is less than 500㎠ / g. Most of the nation's water purification plants, including Seoul's water purification plant, use a large amount of powdered activated carbon as part of the 'high water purification treatment', and it is difficult to regenerate the powdered activated carbon, so most of it is contained in purified water sludge and is treated as waste. Table 2 below shows the sludge treatment costs, purified water chemicals, and powdered activated carbon purchase budget in 2008 for the Seoul water purification plant, and indicates that a large amount of powdered activated carbon is being injected.

<Table 2> 2008 Seoul Water Purification Budget (Unit: 1,000 won)

As described above, silica powder (SiO 2), alumina (Al 2 O 3), and powdered activated carbon, which are major chemical components included in the purified sludge, are representative materials used as adsorbents. Therefore, in order to maximize the characteristics of powdered activated carbon, the present invention was recycled as an adsorbent for odor gas adsorption through a metal salt-based impregnated reagent in order to maximize the high value-added adsorbent.

Hereinafter, the manufacturing method of the malodorous gas adsorbent using the purified sludge according to the present invention will be described.

Method for preparing malodorous gas adsorbent using purified water sludge according to the present invention (S10) step of preparing an adsorbent from purified water sludge through a metal salt-based deposition reagent-(S20) drying step to stabilize the adsorbent-(S30) dried adsorbent It consists of a step of grinding, and will be described in detail each step below.

(S10) Metal salt-based impregnation reagent mixture.

Mix the metal salt-based adhesion reagent suitable for adsorption of ammonia gas, which is a harmful gas, into the purified sludge.

Phosphoric acid and sulfuric acid may be used as the metal salt-impregnated reagent, and the concentration is preferably about 80 to 90%. If the concentration is less than 80%, the adsorption efficiency of the adsorbent is lowered, if more than 90% there is no significant change in the adsorption efficiency.

For example, a mixture of 5% to 20% of the weight of purified water sludge is stirred by mixing an 85% phosphoric acid solution with a metal salt-based impregnated reagent. If the metal salt impregnated reagent is less than 5%, the amount of the purified sludge is too low to be uniformly distributed in the purified sludge, and even if it is uniformly distributed, the content of the metal salt impregnated reagent is low and the function of the adsorbent is lowered. If it is above, since there is no change in adsorption function, 5 to 20% by weight is mixed for efficiency.

The metal salt impregnated reagent is attached to the internal pores of the solid sludge containing purified activated carbon and forms a film on the surface of the solid, and the metal salt impregnated reagent is mixed with the water of the purified sludge to form an impregnated aqueous solution. Therefore, when the metal salt impregnated reagent is mixed, the solid impregnated sludge and the impregnated aqueous solution containing the metal salt impregnated reagent are generated.

When the metal salt-based impregnation reagent is attached to the purified sludge to produce the adsorbent, it is uniformly distributed in all parts of the purified sludge without any chemicals or processes.

Specifically, the purified sludge undergoes a coagulation process to facilitate collection in the treatment plant during the treatment process. That is, the purified water before the mixing of the metal salt-based impregnation reagent is a solid state agglomerated. The metal salt impregnation reagent oxidizes and disperses the flocculation of the hydrous sludge in the colloidal state by aggregation.

The metal salt-based impingement reagent is attached to the pores and surfaces of the powdered activated carbon contained in the purified sludge dispersed at the same time as the floc dispersion of the purified sludge. For example, when sulfuric acid is a metal salt-impregnated reagent, the fine pores increase while the surface activated carbon is partially destroyed or expanded while the powder activated carbon is treated with sulfuric acid. In general, the process of chemically activating with sulfuric acid can be expressed as follows.

[CnHxOy] + H2SO4 → H2O ↑ + S (element) + [CnHxOy + 3]

According to the above formula, when sulfuric acid reacts, it does not block pores of activated carbon at a high activation temperature but causes oxidation or denaturation of hydrocarbons together with the heat of reaction generated in the dehydration reaction of sulfuric acid. This creates a porosity inside the activated carbon powder, the surface is destroyed or expanded.

(S20) first drying.

Solid materials (powder activated carbon, SiO 2, alumina oxide (Al 2 O 3), etc., hereinafter referred to as adsorbents) and impregnated aqueous solution (water content of purified sludge) % Before and after), the metal salt-based adhesion reagent is mixed to form an impregnated aqueous solution.

Drying conditions of the adsorbent may be between 100 and 150 degrees Celsius. The drying temperature is a condition for evaporating the water contained in the adsorbent. At this drying temperature, the water evaporates, but the metal salt-impregnated reagent does not evaporate. As such, when water is evaporated from the adsorbent, it helps to activate the metal salt-based impregnated reagent, and the metal salt-impregnated reagent is uniformly and stably attached, and the concentration of the metal salt-impregnated reagent to the adsorbent can be increased.

(S30) crushed.

The adsorbent produced through the process up to now is pulverized to 10 mesh or less. The grinding of the adsorbent is for increasing the porosity and the specific surface area between the adsorbents, and the particle size of the adsorbent is not limited to 10 mesh or less.

(S40) water glass coating.

(S30) The process of producing the adsorbent is completed by passing through the grinding process. The adsorbent will be used after being exposed to air or moisture, and in this case, the ammonia may be deteriorated not only by adsorption of gas, but also by foreign matters, and to prevent this, water glass may be applied (coated by spray, etc.) to form a protective film. do.

(S40) secondary drying.

After forming a protective film made of water glass, the adsorbent is secondarily dried. Since water glass contains water, it is dried for 1 hour 30 minutes to 2 hours 30 minutes between 100 and 120 degrees Celsius.

(S50) packing.

After secondary drying, the adsorbent is cooled to room temperature (packaging is facilitated and moisture-proof packaging, so if the temperature is high, deformation of vinyl may be concerned).

Through the above steps, the adsorbent can be produced from the purified sludge. For example, the chemical composition of the adsorbent prepared with phosphoric acid as a metal salt-impregnated reagent is shown in Table 3 below.

<Table 3> Chemical Composition of Adsorbents

Analytical Ingredients F Na ₂ O MgO Al ₂ O ₃ SiO ₂ P ₂ O ₅ SO ₃ Cl K ₂ O CaO Fe ₂ O ₃ Result (%) 0.8 0.2 0.4 33.6 18.7 35.8 1.4 0.1 1.8 0.8 5.9

As can be seen from the comparison between the chemical composition of the adsorbent of Table 3 and the chemical composition of the purified sludge of Table 1, the amount of phosphorus pentoxide (P ₂ O ₅ ) capable of adsorbing ammonia is much larger than that of the purified sludge. Able to know.

<Example>

1. Sample: purified water sludge 10Kg (Seoul Guui water purification plant), phosphoric acid 1Kg

2. Manufacturing Process

end. By mixing 10 Kg of purified sludge and 1 Kg of phosphoric acid, phosphoric acid, which is a metal salt-impregnated reagent, was mixed with water in purified sludge to form an aqueous phosphate solution, and solids (activated carbon, alumina oxide, etc.) of purified sludge were immersed.

I. The mixture of the purified sludge and the metal salt-based impregnated reagent was immersed at 25 ° C. to 30 ° C. for 20 hours so that phosphoric acid, which is a metal salt-impregnated reagent, was attached to the solid of the purified sludge. As a result, an adsorbent and an aqueous phosphate solution, which are solids to which the metal salt-based impregnation reagent is attached, are produced.

All. Phosphoric acid-adsorbed adsorbent was dried at 150 degrees Celsius for 20 hours in an electrothermal dryer, and pulverized to 10 mesh through a pulverizer. The surface of the adsorbent was coated by spraying 300 g of an aqueous glass solution.

la. The water glass-coated adsorbent was secondarily dried at 120 degrees Celsius for 2 hours.

hemp. The adsorbent was commissioned by the Korea Chemical Testing Institute for ammonia gas adsorption test. As a result of analyzing the adsorption capacity of ammonia gas, the adsorbent was adsorbed more than 99% after 30 minutes, which proved to be a very good adsorbent (see Fig. 1 test report).

The chemical reaction of phosphoric acid and ammonia can be assumed as follows.

H3PO4 → H + H2PO4

NH3 + H + H2PO4 → (NH3) H2PO4

<Comparison>

Comparing the embodiment of the present invention described above with the conventional (example without using the adsorbent) is as follows.

Table 4 below is an example of the present invention and the conventional test results table.

Table 4 Ammonia Removal Test Results

Test Test subject unit Initial concentration 0.5 hours 1 hours 2 hours 4 hours 6 hours ammonia Conventional ppm 100 100 100 100 97 97 Example 100 1 or less 1 or less 1 or less 1 or less 1 or less

As can be seen from Table 4 and FIG. 2 (Sample in FIG. 2 is an embodiment of the present invention, and Blank is a conventional one), both the embodiment of the present invention and the prior art are not able to remove ammonia gas at an initial stage. As the elapse of this time, the conventional ammonia gas is not removed. However, in the exemplary embodiment of the present invention, most of the ammonia gas is removed after 0.5 hours.

1 is a test report of the adsorbent according to the present invention.

Figure 2 is a conventional graph of the adsorbent according to the present invention.

Claims (5)

delete 5 to 20 parts by weight of any one of metal salt-based deposition reagents selected from the group containing phosphoric acid and sulfuric acid with respect to 100 parts by weight of purified sludge are mixed and immersed for 18 to 22 hours at 25 to 30 degrees Celsius. A first step of allowing the drug to adhere to the purified sludge; A second step of first drying the solid adsorbent and the impregnated aqueous solution produced by the first step for 18 to 22 hours at 100 to 150 degrees Celsius; A third step of coating a protective film through water glass on the surface of the adsorbent first dried through the second step; Odor gas adsorbent using a purified water sludge, characterized in that it comprises a fourth step of secondary drying the protective film coated adsorbent through the third step for 1 hour 30 minutes to 2 hours 30 minutes at 100 degrees to 120 degrees Celsius Manufacturing method. The method of claim 2, wherein the first dried adsorbent through the second step is pulverized to 10 mesh or less. 5. delete Odor gas adsorbent using purified sludge, which is prepared according to claim 3.

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