KR101317574B1 - Method for manufacturing absorbent using sludge generated in total phosphorus processing facility and absorbent manufactured by the method - Google Patents

Abstract

PURPOSE: A method for manufacturing an absorbent using total phosphorus sludge and an absorbent manufactured by the same method are provided to prevent secondary pollution induced by the treatment of sludge and create economic benefit generated by the use of waste by recycling sludge generated in a facility for processing total phosphorus after purification. CONSTITUTION: A method for manufacturing an absorbent comprises the steps of: eluting aluminum and silicon by controlling a pH in the range between 2 and 3 in the process of adding acid including 100 parts by weight of total phosphorus sludge generated in a total phosphorus processing facility, 50 to 100 parts by weight of water, sulfuric acid and hydrochloric acid; mixing 1 to 5 parts by weight of both or either of phosphoric acid and a phosphate compound with 100 parts by weight of the total phosphorus sludge from which aluminum and silicon has been eluted; generating a zeolite reactant by inducing a hydrothermal reaction in the process of evaporating the moisture of the compound; producing a powdery absorbent by dehydrating and drying the reactant; making the powdery absorbent into a granular absorbent; making a dough by mixing and kneading the powdery absorbent with 0.1 to 10 parts by weight of a solidifying agent; and producing a granular absorbent by molding the dough into a granular form. [Reference numerals] (AA) NH_3 concentration (ppm); (BB) Specimen concentration; (CC) Deodorization rate; (DD) Deodorization rate (%); (EE) Elapsed time (min)

Description

METHOD FOR MANUFACTURING ABSORBENT USING SLUDGE GENERATED IN TOTAL PHOSPHORUS PROCESSING FACILITY AND ABSORBENT MANUFACTURED BY THE METHOD}

The present invention relates to an adsorbent using gross sludge, and more particularly, purifies gross phosphorus contaminating four rivers and recycles gross sludge generated from gross phosphorus treatment facilities to prevent secondary pollution due to sludge treatment and waste. The present invention relates to a method for preparing an adsorbent using total sludge generated at a total phosphorus treatment plant that can generate economic benefits from the use of and an adsorbent prepared by the method.

Recently, as the research on the recycling of sewage sludge has been actively conducted, many commercialized technologies have been developed. The recycling methods of such sludge include carbonization, composting, and solidification methods. It is one of the useful treatment methods that can be utilized, and considering the domestic reality that it is difficult to secure landfill and stable soil for narrow land, the development and practical use of substitute cover material to replace soil will extend the life and environment of existing landfill. It is very important in terms of pollution prevention and economics. In addition, if the prerequisites for the ideal sludge recycling, which should not affect the human body and the environment, are met, recycling of the sludge is very important in terms of economic and environmental aspects.

Recently, various technologies have been proposed to recycle sewage sludge solids by covering various solidifying agents by adding various solidifying agents to sewage sludge. Among them, Korean Patent Publication No. 2000-25028 has been proposed. Discloses a technique of mixing gypsum, quicklime, cement and the like as sewage sludge with heating to below 500 ° C. and then cooling it in the air as landfill. However, in the existing method using cement and quicklime as a solidifying agent as above, exothermic reaction occurs during the mixing, curing and drying of sewage sludge and additives. There is a problem such as is generated.

On the other hand, the source of odors in livestock farms can be caused by manure excreted by livestock and livestock, and the quality of feed used by livestock farmers when raising livestock, by the excretion habits of livestock or by the collection, separation and collection of manure Odor may vary depending on the back, but its main source is the decay of livestock manure. Odor generation is affected by temperature, humidity, wind, etc. Especially at low pressures, the atmosphere spreads low on the ground, so many complaints occur due to the diffusion of odors in the surrounding area, and in winter, the ventilation is blocked for heating in the barn. It is known that the concentration of odor-causing substances, especially ammonia, in the barn is quite high. Odor generation in livestock farms is mainly caused by ammonia gas from the decay of livestock manure, and this ammonia gas is very sensitive to body tissues, especially mucosal tissues. Not only does it adversely affect the health of farmers and farm officials working in farmhouses, but it also adversely affects the health of the animals actually being raised, especially the pigs of pig farms. In pigs, especially those with sensitive and fragile young piglets, those with weak bronchial and lung tissues that act directly on lung tissue and have a detrimental effect on tracheal epithelial and lung tissues can cause pathogens such as other bacteria, viruses, and fungi. Are likely to be exposed to

There is a problem that the economic damage of the farmhouse is increased.

In addition, there is a problem that an indirect economic loss is increased due to civil complaints in the surrounding area due to the odor in the industrial complex. In order to reduce air odor by various methods such as activated carbon, cleaning, and biofilters, there are many problems in operating and operating them at the origin of origin due to economic burden and difficulty of technology.

Recently, the Ministry of Environment recommends reducing the concentration of phosphorus in the discharged water from the four river basins to less than 0.5 mg / l and gradually applying it to all sewage and wastewater treatment plants nationwide. It is planned.

Phosphorus is a eutrophication that is several orders of magnitude higher than nitrogen, and removal of phosphorus is a very important way to protect rivers. Phosphorus removal concentration by conventional microorganisms is difficult to remove less than 0.5 mg / ℓ has been proposed to solve this problem, among which the chemical treatment method using an organic alum-based flocculant is presented as the first priority

have.

Patent Publication No. 10-2012-0097278 Patent Registration No. 10-0702602

The present invention is to solve the problems described above, to purify the total phosphorus polluting the four rivers, and to recycle the sludge generated in the total phosphorus treatment facility after purification to prevent secondary pollution due to sludge treatment and to utilize the waste It is an object of the present invention to provide a method for preparing an adsorbent using total sludge generated in a total phosphorus treatment plant that can generate economic benefits, and an adsorbent prepared by the method.

In the method for preparing an adsorbent using total phosphorus sludge generated in the total phosphorus treatment plant according to the present invention, 100 to 100 parts by weight of total phosphorus sludge is 50 to 100 parts by weight of water and sulfuric acid, hydrochloric acid, and other commonly used strong or weak acids. Adjusting to 2 to 3 to elute aluminum (Al) and silica sand (Si) to the maximum; A second step of preparing a mixture by mixing 1 to 5 parts by weight of at least one of phosphoric acid and a phosphoric acid compound with respect to 100 parts by weight of the total sludge from which aluminum and silica are eluted through the first step; A third step of generating a zeolite reactant (alcohol and sandpaper zeolite and a reactant of vercite and silica gel in an amorphous state) by evaporating water of the mixture mixed by the second step to induce hydrothermal synthesis; Dehydration and drying of the reactants reacted by the third step to prepare a powdered adsorbent in the fourth step, 5 to prepare a granular (pellet) adsorbent by using the binder in the powdered adsorbent prepared in the fourth step Dehydration of the reactants reacted by the step, and also three steps, characterized in that it comprises the preparation of a granular (pellet) adsorbent immediately.

According to the method of preparing an adsorbent using total phosphorus sludge generated in the phosphorus treatment plant according to the present invention and the adsorbent prepared by the method, sludge generated in the phosphorus treatment plant after purification is purified by purifying phosphorus contaminating four rivers. As a waste sludge, it is difficult to dispose of it by composting, carbonization, fueling after drying, etc., so that the landfill can be recycled, thereby preventing secondary pollution due to sludge treatment and generating economic benefits from the utilization of waste. .

1 is a graph showing the adsorption performance of ammonia according to an embodiment of the present invention.
2 is a graph showing the adsorption performance of formaldehyde according to an embodiment of the present invention.
3 and 4 are graphs showing the concentration changes of ammonia and trimethylamine according to the examples and comparative examples of the present invention, respectively.

A method for preparing an adsorbent using total sludge generated in a total phosphorus treatment plant according to the present invention is as follows.

1. Sludge pretreatment.

The sludge generated from the total phosphorus treatment facility is chemically treated with organic alum flocculant to remove residual phosphorus to prevent eutrophication of the effluents discharged from the existing sewage treatment plant, for example, to preserve the water quality of four rivers. Sludge generated through flocculation and dehydration is prepared.

In accordance with the government's policy on water management and revitalization of the four rivers, we will establish a tertiary treatment facility to remove pollutants such as TP, BOD, and SS. Fine particles, suspended solids and trivalent phosphate ions are aggregated using an inorganic flocculant to form flocs and the trivalent metal ions react with trivalent phosphate ions causing total phosphorus to produce poorly water-soluble phosphates.

Therefore, it is possible to directly check (observation) of chemical injection and flocculation state for floc formation by chemical coagulation reaction. Maximize coagulation efficiency through time.

The flocculant is slightly expensive, but the floc formation rate is fast and the performance is about 3 to 4 times that of alumina, and basic aluminum chloride (PAC, Al (OH) mCl 6-n) that does not deteriorate at low temperature is used.

The water content of the dewatered sludge varies widely depending on the type of dehydrator, but it is generally maintained in the 75 ~ 85% range.

On the other hand, the total sludge generated in the total phosphorus facility contains aluminum (Al) and silica sand (Si) to improve the function of the adsorbent, and the sludge is agglomerated and dehydrated, water and pH regulators (renewed sulfuric acid or industrial sulfuric acid, Hydrochloric acid, strong acid such as nitric acid, weak acid type) is added to adjust the pH to 2-3 and stirred for 1 to 3 hours to elute aluminum (Al) and silica sand (Si). Water is mixed 50 ~ 100 parts by weight, preferably 80 parts by weight with respect to 100 parts by weight of sludge, if less than 50 parts by weight is not smoothly stirred during hydrothermal synthesis, the synthetic effect is insufficient, if more than 100 parts by weight of pre-treatment It takes a long time, adversely affecting energy costs.

In addition, the temperature is maintained at about 60 ℃ while the stirring degree is maintained at about 100 ~ 150rpm, the reason for adjusting the pH to 2-3 is the optimum elution pH, the temperature is higher than room temperature to shorten the elution time and increase the reaction degree Keep it. The degree of agitation allows the aluminum and silica sand to be eluted best and optimally in the sludge through the general rapid stirring method.

2. Total Sludge Pretreatment Manufacturing.

The adsorbent of the present invention is a starting material for the total sludge generated in the total phosphorus facility, and the total insludge generated from the total phosphorus treatment facility (sludge in which pH is adjusted and the aluminum and silica are eluted), phosphoric acid (H3PO4) (or phosphoric acid compound). ) As the material.

Phosphoric acid is mixed in an amount of 1 to 5 parts by weight, preferably 3 parts by weight, based on 100 parts by weight of the sludge generated in the total phosphorus treatment plant. If it is less than 1 part by weight, the effect of the adsorbent is insufficient. Since no molar ratio formation of PO4 ions is achieved, the effect is insignificant in terms of odor control and the material cost is increased. The reason for using the waste phosphoric acid is to hydrothermally react the phosphorus-containing sludge to have a zeolite structure and to dissociate the sludge mass and to further shorten the drying time in a subsequent process.

Thus, pretreatment total phosphorus sludge, phosphoric acid (or phosphate compound, etc.) is prepared, and the mixture is prepared in a stirrer at a ratio of 1 to 5 parts by weight of phosphoric acid based on 100 parts by weight of sludge.

3. Hydrothermal synthesis reaction.

The mixture prepared by the total sludge pretreatment process is stirred for 1 to 3 hours while maintaining a temperature of 100 ~ 120 ℃ through a heater so that the reaction by hydrothermal synthesis occurs. When reacting in a hydrothermal stirrer, air is fed into the lower part of the stirrer or on the side through an air compressor to increase the reaction speed and to improve the time and reaction conditions for the hydrothermal synthesis by making the sludge as a clay. It also aims to maintain the quality control in the production of products by reducing the odor of the total sludge itself. In addition, the air injection may be performed in the total sludge pretreatment process. Since the phosphoric acid constituting the mixture has a boiling point of about 160 ° C. and all of the phosphoric acid will evaporate if the boiling point temperature is higher than the boiling point temperature, it is preferably maintained at 150 ° C. or lower and 120 ° C. or lower. As a result, no water content control effect can be expected.

This hydrothermal synthesis reaction produces a honeycomb zeolite reactant which improves the adsorbent functions such as alpo- and sandpaper zeolites and vercite and silica gel in the amorphous state.

4. sorbent manufacture.

 Since the reactant (the honeycomb zeolite reactant) that has undergone the reaction process maintains a water content of about 85 to 90%, moisture may lower the deodorizing effect, and thus, the reactant is controlled by using a mechanical method such as a dehydrator.

Moisture control can be achieved by dehydration, which is a physical method, and drying, which is a chemical method. First, the moisture content of the reactants is adjusted to 50 to 60% using a physical dehydrator (various dehydrators such as pressurization can be used). It is dried at 12 degreeC or more (12-15 hours). As such, when the primary dehydration by the physical method and the secondary drying by the chemical method are combined, the cost of heating can be reduced and the water content control time can be shortened.

Through the above process, a powdered adsorbent is produced.

The powdered adsorbent prepared by the present invention may be used as a deodorant without processing, or may be prepared as a granular (pellet type) adsorbent and the manufacturing process of the granular adsorbent is as follows.

Kneading is prepared by mixing and kneading 0.1 to 10 parts by weight of the solid agent to 100 parts by weight of the powdered adsorbent. If the solid agent is mixed at less than 0.1 part by weight, the hardness of the granular form may be a problem. If the solid agent is mixed at more than 10 parts by weight, the workability may be degraded and the adsorption performance may be a problem.

The solid material may be either a natural polymer material or a synthetic polymer material. The natural polymer material may include starch, cellulose, agar, alginate, rubber, gelatin, glue and protein. In any one of the above, the synthetic polymer material is any one of known polymer resins synthesized by copolymerizing polyester, polyethylene, polypropylene, polystyrene alone or monomers thereof.

 The synthetic polymer resin may be weak in high temperature heat, so the strength and performance of the adsorbent may be reduced due to the high temperature exhaust gas flowing into the adsorbent, which is an air pollution prevention facility.

Therefore, in this invention, it is preferable to use starch as a solid agent.

Starch not only lowers the production cost, but also increases the strength of the adsorbent and the pore area of the adsorbent, which is the final product of the present invention, and shows very strong properties against acid and base resistance.

The starch used in the present invention may be any type of starch such as corn, potato, starch or sweet potato.

The present invention is used by mixing 0.1 to 10 parts by weight of the gelled starch to 100 parts by weight of the powdered adsorbent using the total sludge. More preferably, 1 to 5 parts by weight of the gelled starch is mixed with 100 parts by weight of the powder adsorbent to prepare the mixture.

The reason for mixing in the above weight parts is that it is difficult to maintain the critical strength of the pellets or the cyclic adsorbent when the content of the gelled starch is less than 0.1 parts by weight based on 100 parts by weight of the powdered adsorbent. Here, the critical strength of the adsorbent means the minimum strength to prevent abrasion and crushing in installing the adsorbent in the adsorption tower, an air pollution prevention facility. In addition, when the content of the gelled starch exceeds 10 parts by weight based on 100 parts by weight of the powdered adsorbent, there is a problem of long-term storage due to the excessive content of starch, that is, corruption, and it is not economical even in the production and manufacturing cost.

Gel starch means that 5 to 20 parts by weight of starch is mixed with 100 parts by weight of water and heated to 100 ° C. or more (100 to 120 ° C.) to boil until it becomes gel. Cooling the mixture of boiled water and starch still maintains the gelled starch.

The method of kneading the powdered adsorbent and the solid agent can be kneaded using a conventional kneader and kneaded sufficiently so that the adsorbent and the gelled starch can be evenly mixed. The mixture of the adsorbent and solid agent so kneaded is an adsorbent material.

The kneaded adsorbent material is preferably maintained at a water content of 20 to 40%. In this case, when the moisture content is less than 20%, there may be a problem such as shaping and shaping when forming the shape of the adsorbent to be described below, and when the water content exceeds 40%, it may be difficult to shape the shape at a high moisture content. .

According to the present invention, when the above-mentioned weight parts of adsorbents, solids, etc. are mixed, the maintenance of the moisture content can be easily achieved, and incidentally, moisture evaporation or moisture reinforcement can be maintained for the kneaded adsorbent material. Of course, you can add a device that can give.

The kneaded adsorbent material, which is a mixture of the kneaded adsorbent powder and the solid agent, is introduced into a molding machine to form a shape in pellet or ring form. In the present invention, the molding machine means a press-type extruder, a screw, or the like, and means a device or means capable of discharging by applying pressure to the kneaded adsorbent material. In the present invention, the size of the pellets can be varied, and preferably 4 to 5 mm in diameter and 4 to 5 mm in length can maximize the efficiency of deodorization. Also, the diameter of the annular shape is preferably 4 to 10 mm.

In the present invention, the molded pellets or the cyclic adsorbent are dried in a dryer. When drying in a dryer, it is preferable to dry at a temperature of 90 ~ 120 ℃ in order to prevent the destruction of pellets or cyclic adsorbent, and to dry the moisture content less than 3% (that is, to dry the moisture content at the above temperature It is not a numerical value of the drying time).

When the pellets or cyclic adsorbents formed in this way are used in the adsorption tower, an air pollution prevention facility, the odor-inducing substances such as ammonia gas, trimethylamine, etc., which have a polar smell, formaldehyde, TPH Removal rate is shown.

Meanwhile, the present invention may prepare a granular adsorbent using the honeycomb zeolite reactant directly without the powdering process based on the above-described method.

<Examples>

1. sorbent manufacture.

80 parts by weight of water and sulfuric acid were added (added until the pH of the total sludge reached 3) based on 100 parts by weight of total sludge to elute aluminum (Al) and silica sand (Si). A mixture of 5 parts by weight of the phosphate compound with 100 parts by weight of aluminum and silica sand eluted was stirred for 2 hours while maintaining a temperature of 110 ° C. through a heater to induce a hydrothermal synthesis reaction and supply air with a honeycomb type. The zeolite reactant was produced. The honeycomb zeolite reactant was dehydrated and dried at 110 ° C. for 13 hours to prepare a powdered adsorbent, and then the powdered adsorbent was prepared by using a known pellet machine.

2. Performance.

In order to apply typical alkaline odorous substances such as ammonia and trimethylamine as a filter for removing particulate sorbents, adsorption capacity of odorous substances was measured. Adsorption experiments were carried out using a fixed bed continuous test method where a certain concentration of adsorbate was passed through an adsorbent bed at the inlet of the column containing the adsorbent, and the concentration of adsorbate was measured at the outlet.

In this performance test, the adsorbent was used to form a powdered adsorbent sample into a pellet type of 5 mm in length and 3 to 5 mm in length and introduced into an acrylic column having a diameter of 50 mm and a depth of 30 mm.

At this time, the adsorbate passed about 150 ppm of ammonia gas and 50 ppm of trimethylamine gas at a rate of 2 L / min. At this time, the introduced ammonia gas and trimethylamine gas used a standard gas. Then, the gas concentration was measured for the air which passed the adsorbent using the gas detection tube. For comparison with the adsorbent according to the present invention, conventionally commonly used impregnated activated carbon was tested under the same adsorbate conditions. In addition, for comparison with the adsorbent according to the present invention, an adsorbent made by drying at 110 ° C. in an oven and heat-treated for 2 hours at different firing temperatures at 600 ° C. in an electric furnace was used.

The adsorption performance of ammonia gas (NH ₃ ) and formaldehyde (HCHO) according to the elapsed time was investigated to determine the deodorizing capacity of the granular adsorbent. After 120 minutes, it was found that 98% or more of ammonia gas (NH ₃ ) and formaldehyde (HCHO) were adsorbed (see FIGS. 1 and 2).

3 and 4 are graphs showing changes in concentrations of ammonia gas and trimethylamine gas according to the present experiment [heat treatment temperature change (110 ° C., 600 ° C.), concentration change graph at the outlet of commercial impregnated activated carbon with time]. As the heat treatment temperature was increased from 110 ° C to 600 ° C, the adsorption performance at the outlet increased slightly. The specific surface area of the adsorbent at 110 ° C (specific surface area 48.2m ² / g) and 600 ° C (specific surface area 123.4m ² / g) was about three times larger. In addition, the adsorption capacity is higher than that of commercially available impregnated activated carbon. The activated carbon is detected in about 60 minutes to about 2 ppm and gradually approaches an initial concentration of 150 ppm as time passes. On the other hand, although the adsorbent according to the present invention does not change significantly depending on the heat treatment state, it can be seen that it has an adsorption capacity of about 4 times or more than the impregnated activated carbon commercialized as it is detected at about 1 to 5 ppm at about 240 minutes. Similar to ammonia gas, trimethylamine gas showed a similar tendency, and thus the adsorbent prepared showed higher removal efficiency than the impregnated activated carbon commercialized in alkali gas, that is, ammonia and trimethylamine odor.

Claims (6)

A first step of eluting aluminum (Al) and silica sand (Si) by adjusting the pH to 2 to 3 by adding 50 to 100 parts by weight of water and an acid including sulfuric acid and hydrochloric acid to 100 parts by weight of total sludge;
A second step of preparing a mixture by mixing 1 to 5 parts by weight of phosphoric acid and at least one phosphoric acid compound with respect to 100 parts by weight of the total sludge from which aluminum and silica are eluted through the first step;
A third step of generating a zeolite reactant by evaporating water of the mixture mixed by the second step to induce hydrothermal synthesis;
A fourth step of preparing a powdered adsorbent by dehydrating and drying the reactants reacted by the third step,
And a fifth step of preparing the powdered adsorbent prepared through the fourth step into a granular adsorbent.
The fifth step is a 5-1 step of preparing a dough by mixing and kneading 0.1 to 10 parts by weight of the solid agent to the powder-type adsorbent prepared in the fourth step; Method of manufacturing the adsorbent using the total insludge generated in the total phosphorus treatment facility comprising the step 5-2 to form a granular adsorbent by molding the dough kneaded through the step 5-1 into a granular form. . delete The method of claim 1, wherein in the fifth step, any one of a natural polymer material or a synthetic polymer material is used as the solid agent, wherein the natural polymer material is starch, cellulose, agar, alginic acid, rubber, gelatin, glue, The synthetic polymer material is any one of proteins, and the total polymer generated in the treatment plant is characterized in that any one of the known polymer resins synthesized by copolymerizing polyester, polyethylene, polypropylene, polystyrene alone or monomers thereof. Method for preparing adsorbent using sludge. The method according to claim 3, wherein the starch of the natural polymer material is heated to produce a gel state at 100 ~ 120 ℃ after mixing 5 to 20 parts by weight of starch with respect to 100 parts by weight of water in the total phosphorus treatment facility Method for producing adsorbent using the total sludge produced. The method according to claim 1, wherein the fourth step is dehydrated and dried at 110 ~ 140 ℃ for 12 to 15 hours the zeolite reactant reacted by the third step in the total phosphorus treatment facility, characterized in that for preparing a powdery adsorbent Method for producing adsorbent using the total sludge produced. An adsorbent using a total phosphorous sludge generated in a total phosphorous treatment plant, characterized in that produced by the adsorbent manufacturing method using a total phosphorous sludge generated in the total phosphorus treatment plant according to any one of claims 1 or 3 or 4.

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