KR102539015B1 - A method for preparing organic adsorbent based on coffee wastes and steel making slag for selective recovery or removal of phosphorus, a organic adsorbent therefrom, and use of the same - Google Patents

Abstract

In the present invention, a) washing biomass with distilled water for 0.5 to 3 hours, repeating sedimentation for 20 minutes, filtering, and b) drying the washed biomass in an oven at 60 to 105 ° C. for 12 to 36 hours and c) mixing the dried biomass with industrial by-products at a ratio of 1:0.01 to 1:3, d) putting the mixture into an electric furnace and heating it at 3 to 20° C./min under 0.2 to 3 L nitrogen gas/min at 300° C./min. After raising the temperature to ~ 900 ℃, maintaining at 300 ~ 900 ℃ for 0.5 ~ 4 hours and cooling, e) repeating washing the mixture that has gone through the process d) with distilled water for 0.5 ~ 3 hours, followed by filtration, f) drying the washed and filtered in an oven at 60 to 105 ° C. for 12 to 36 hours, and g) screening only those that have passed 80 to 625 mesh through a 80 to 625 mesh sieve- A method for preparing an organic adsorbent based on industrial by-products is provided.

Description

A method for preparing organic adsorbent based on coffee wastes and steel making slag for selective recovery or removal of phosphorus, a organic adsorbent therefrom , and use of the same}

The present invention relates to a method for preparing an organic adsorbent based on coffee grounds-steelmaking slag for selective phosphorus recovery, the organic adsorbent and its use.

Slag, which accounts for the largest proportion among steelworks by-products, is largely divided into blast furnace slag generated in the process of manufacturing molten iron in a blast furnace and steelmaking slag generated in the refining process of removing impurities from molten iron. However, since blast furnace slag is currently used mainly for construction materials such as admixtures and substitutes for cement and crushed aggregate for roadbed materials, its recycling is not on the rise.

However, steelmaking slag is crushed after cooling and partially recycled as a raw material for the steelmaking process by magnetic separation. Most of the steelmaking slag is mainly recycled as a raw material for cement or aggregate for road/port civil engineering works, but some of it is not utilized and is dumped for disposal. am. The cause of the low recycling rate of steelmaking slag is that due to its high weight and weathering and expansibility, the processing and recycling costs are relatively high, so it is difficult to effectively recycle it.

On the other hand, most of the sewage treatment facilities in Korea do not treat phosphorus (P) properly, so eutrophication of lakes and rivers and occurrence of green and red tides are repeated. In particular, sewage generated from apartment complexes contains flush toilet manure and has a high phosphorus (4-6mg/L) concentration. Phosphorus in wastewater can be removed using anaerobic and aerobic conditions in a biological phosphorus removal process. That is, phosphorus is released under anaerobic conditions, and excess phosphorus is ingested by microorganisms under aerobic conditions in the latter stage. Thereafter, phosphorus is removed by discarding the microorganisms (sludge) that have ingested excess phosphorus in the reactor. As such, the biological phosphorus removal process is very complex to apply in a real-scale treatment plant, and phosphorus release under anaerobic conditions or excess phosphorus intake under aerobic conditions is easily suppressed by external conditions. In addition, since the biological phosphorus removal process removes phosphorus by discarding the sludge, a large amount of sludge is generated compared to other processes, resulting in high sludge treatment costs.

Phosphorus is one of the essential nutrients for the generation of DNA and RNA of human and aquatic microorganisms and the transfer of electrons in the body.

However, it is known that phosphate ore will be exhausted within about 100 years due to the continuous increase in the use of phosphorus due to the fertilizer industry, chemical industry, and feed industry. Therefore, the export volume of phosphate ore is decreasing, and the price thereof is increasing. On the other hand, since phosphorus can cause eutrophication in water systems, its concentration is regulated internationally. In order to solve these problems, it is necessary to develop a technology capable of effectively recovering phosphorus from an aqueous system.

Currently, among various phosphorus recovery methods, the adsorption process is widely applied due to its simple operation and high phosphorus recovery rate.

Since the phosphorus recovery rate is mainly influenced by mineral components such as calcium and magnesium present in the adsorbent, methods of reforming through chemicals (eg, CaCl ₂ , MgCl ₂ ) are applied to increase these mineral components.

However, since the improvement in the phosphorus recovery rate is achieved by increasing the amount of chemicals used, the overall cost of producing the adsorbent increases, which can be a problem.

Steelmaking slag is a major by-product generated during iron manufacturing, and its global production (as of 2014) is about 250,000 tons. The recycling of steelmaking slag accounts for less than 30% of the total amount generated, and the recycling field is mainly limited to cement production and road construction.

In addition, phosphorus in wastewater is usually removed in the form of waste together with solids in the process of removing solids using a coagulant, so it is difficult to recycle as a resource.

[Prior Patent Literature]

Korean Patent Publication No. 1020130116955

The present invention was made in response to the above needs, and an object of the present invention is to provide a coffee ground-steel slag-based organic adsorbent manufacturing method that is harmless to humans and the natural environment and can economically and effectively achieve phosphorus recovery through an easy method. is to do

Another object of the present invention is to provide a coffee ground-steel slag-based organic adsorbent that is harmless to humans and the natural environment and can economically and effectively achieve phosphorus recovery through an easy method.

Another object of the present invention is to provide a method for recovering phosphorus from steelmaking slag through an easy method that is harmless to humans and the natural environment.

In order to achieve the above object, the present invention a) washing the biomass with distilled water for 0.5 to 3 hours, repeating the precipitation for 20 minutes, filtering,

b) drying the washed biomass in an oven at 60 to 105 ° C. for 12 to 36 hours;

c) The reason for mixing the dried biomass with industrial by-products at a ratio of 1:0.01 to 1:3 is that if the industrial by-products are lower than the lower limit of the mixing ratio, the effect is less, and if it is out of the upper limit, the amount of industrial by-products is higher than the amount of coffee grounds. Since the amount is large, harmful metal components can leak out, so the dried biomass is mixed with industrial by-products at a ratio of 1:0.01 to 1:3,

d) Put the mixture in an electric furnace and raise the temperature to 300 to 900 ° C at 3 to 20 ° C / min under 0.2 to 3 L nitrogen gas / min, hold at 300 to 900 ° C for 0.5 to 4 hours, and cool, where the carbonization temperature is If the temperature exceeds 900 ℃, the economic feasibility deteriorates, so this temperature range was adopted.

e) repeating washing the mixture that has gone through step d) with distilled water for 0.5 to 3 hours, followed by filtration;

f) drying the washed and filtered in an oven at 60 to 105 ° C. for 12 to 36 hours;

g) If it is less than 80 mesh, it is not easy to pass through, and if a sieve larger than 625 mesh is applied, the economy is reduced in the process of grinding the particles, so only those that have passed 80 to 625 mesh through the 80 to 625 mesh sieve A biomass-industrial by-product-based organic adsorbent manufacturing method comprising screening is provided.

In one embodiment of the present invention,

The biomass is preferably selected from the group consisting of walnut shells, rice straw, sawdust, coffee waste, rice bran, red pepper stems, organic sludge, fruit shells, forestry by-products, and forest by-products, but is not limited thereto.

In one embodiment of the present invention,

The biomass is preferably coffee waste, but is not limited thereto.

In another embodiment of the present invention,

The industrial by-product is preferably steelmaking slag or coal ash, but is not limited thereto.

In one embodiment of the present invention,

The industrial by-product is preferably steelmaking slag, but is not limited thereto.

In addition, the present invention provides a biomass-industrial by-product based organic adsorbent prepared by the production method of the present invention.

In one embodiment of the present invention,

The biomass is preferably selected from the group consisting of walnut shells, rice straw, sawdust, coffee waste, rice bran, red pepper stems, organic sludge, fruit shells, forestry by-products, and forest by-products, but is not limited thereto.

In one embodiment of the present invention,

The biomass is preferably coffee waste, but is not limited thereto.

In another embodiment of the present invention,

The industrial by-product is preferably steelmaking slag or coal ash, but is not limited thereto.

In one embodiment of the present invention,

The industrial by-product is preferably steelmaking slag, but is not limited thereto.

In addition, the present invention provides a method for recovering or removing phosphorus from waste by treating waste containing phosphorus with the organic adsorbent based on biomass-industrial by-product of the present invention.

In one embodiment of the present invention,

In the above method, the adsorbent input amount is 0.001 to 50 g/L, which is less effective below the lower limit of this range, and when it exceeds the upper limit, the economical efficiency is poor. Not limited.

In another embodiment of the present invention,

The waste is preferably livestock manure and wastewater, but is not limited thereto.

In addition, the present invention provides a composition for recovering phosphorus from waste containing phosphorus containing the biomass-industrial by-product based organic adsorbent of the present invention as an active ingredient.

The present invention will be described below.

The present invention a) biomass (e.g., walnut shells, rice straw, sawdust, coffee waste, rice bran, red pepper stalks, organic sludge, fruit shells, forestry by-products, forest by-products, etc.) and industrial by-products (e.g., steelmaking slag, coal ash, etc.) mixing; b) a method for preparing an organic adsorbent including carbonizing the mixture, an organic adsorbent prepared by the method, and a phosphorus recovery method using the same.

The coffee waste-steelmaking slag-based organic adsorbent prepared by the method of the present invention can simply produce an organic adsorbent through a carbonization process after simply mixing two types of waste. In addition, the main component of steelmaking slag is mainly mineral oxides (e.g., FeO, MgO, CaO, etc.) and has a high reactivity with phosphate, so it has the advantage of being able to selectively recover phosphorus in the water system.

1 is a view showing a coffee waste-steelmaking slag-based organic adsorbent manufacturing process of the present invention;
2 is a diagram explaining a phosphorus recovery method through an organic adsorbent based on coffee waste-steelmaking slag prepared by the method of the present invention;
3 is an experimental result showing that the phosphorus recovery efficiency is increased through the coffee waste-steelmaking slag-based organic adsorbent prepared by the method of the present invention.
In FIG. 3, SCGB _P : means an adsorbent produced by thermally decomposing coffee waste at 700 degrees for 1.5 hours by raising the temperature by 5 degrees per minute under nitrogen conditions of 0.25 L / min,
SCGB _SS : A mixture of coffee waste and steelmaking slag in a weight ratio of 1 to 1, which is heated at a rate of 5 degrees per minute under a nitrogen condition of 0.25 L/min and thermally decomposed at 700 degrees for 1.5 hours.
Q _e (mg/g) represents the amount of phosphate adsorption when phosphate ions and other anions exist together.
As can be seen from FIG. 3, SCGB _P exhibits a low phosphorus recovery rate in the presence of other anions, but SCGB _SS exhibits a high phosphorus recovery rate even in the presence of other anions. Therefore, it can be seen that when the steelmaking slag and the coffee grounds are recycled, the waste treatment cost can be reduced and phosphorus can be effectively recovered.

Hereinafter, the present invention will be described in more detail through non-limiting examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not to be construed as being limited by the following examples.

Example 1: Preparation of organic adsorbent based on coffee waste-steelmaking slag

In the present invention, various biomass including coffee waste (e.g., walnut shells, rice straw, sawdust, coffee waste, rice bran, red pepper stalks, organic sludge, fruit shells, forestry by-products, forest by-products, etc.) can be used as raw materials. As an embodiment of the present invention, a method using coffee waste as a raw material is described.

The coffee waste was washed with distilled water for 0.5 to 3 hours, and after 20 minutes of precipitation was repeated 3 to 6 times, filtering was performed.

The washed coffee waste was dried in an oven at 60 to 105 ° C. for 12 to 36 hours.

The dried coffee waste was mixed with steelmaking slag at a ratio of 1:0.01 to 1:3.

The mixture was put into an electric furnace and heated to 300 to 900 ° C at 3 to 20 ° C / min under 0.2 to 3 L nitrogen gas / min, maintained at 300 to 900 ° C for 0.5 to 4 hours, and allowed to cool.

Washing the mixture subjected to the carbonization process with distilled water for 0.5 to 3 hours was repeated 3 to 6 times, and then filtered.

The washed and filtered was dried in an oven at 60 to 105° C. for 12 to 36 hours.

Coffee waste-steel slag-based organic adsorbent was prepared by screening only those that passed 80-625 mesh through a 80-625 mesh sieve.

Example 2: Phosphorus Recovery Method Using the Skin-Steelmaking Slag-Based Organic Adsorbent of the Present Invention

The amount of the adsorbent prepared in Example 1 was 0.001 to 50 g/L,

The pH of the solution to be treated was 3 to 11,

The temperature of the treatment solution is 5 ~ 45 ℃;

The adsorbent treatment time ranged from 0.001 to 144 hours.

The concentration of the strip to the adsorbent was < 10 g/L;

Agitation RPM was 50 to 300.

3 is a graph showing the results of performing phosphorus recovery through an organic adsorbent based on coffee waste-steelmaking slag through experiments.

In FIG. 3, SCGB _P : an adsorbent produced by thermally decomposing coffee waste at 700 degrees for 1.5 hours by raising the temperature by 5 degrees per minute under nitrogen conditions of 0.25 L/min,

SCGB _SS : A mixture of coffee waste and steelmaking slag in a weight ratio of 1 to 1, which is heated at a rate of 5 degrees per minute under a nitrogen condition of 0.25 L/min and thermally decomposed at 700 degrees for 1.5 hours.

Q _e (mg/g) represents the amount of phosphate adsorption when phosphate ions and other anions exist together.

As can be seen from FIG. 3, SCGB _P exhibits a low phosphorus recovery rate in the presence of other anions, but SCGB _SS exhibits a high phosphorus recovery rate even in the presence of other anions. Therefore, it can be seen that when steelmaking slag and coffee grounds are recycled, phosphorus can be effectively recovered while reducing waste disposal costs.

In the experimental conditions of FIG. 3, the adsorbent capacity is 0.5 g/L,

solution pH = 7,

solution temperature = 25 °C,

Stirring speed = 150 rpm,

Initial concentration of anion coexisting with phosphate ions = 20 mg/L,

Contact time = 24 h.

In this experiment, first, ICP-OES was applied to obtain the concentration of phosphorus.

The adsorption amount (Q _e ) applies the formula of (initial concentration of phosphorus, mg/L - final concentration of phosphorus, mg/L)*V(volume of reference solution, L)/M(amount of recovery agent used, g) and saved.

If phosphorus cannot be selectively recovered, it can be determined that the Q _e value decreases when other anions are present. Therefore, since the Q _e value of SCGB _SS does not change significantly even in the presence of other anions, it can be seen that SCGB _SS can selectively recover phosphorus.

The anions free histogram in FIG. 3 is the phosphorus recovery amount when no other anions exist.

Claims (12)

delete A mixture of coffee waste and steelmaking slag in a weight ratio of 1:1 was heated at a rate of 5 degrees Celsius per ^minute under a nitrogen condition of 0.25 L/min and pyrolyzed at 700 degrees Celsius for _1.5 ^hours . composed of ₄ ^2- and CO ₃ ^2- A method for recovering dissolved phosphate in the presence of one or more anions among the anions. delete delete delete delete delete delete delete delete delete delete

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