KR20100124143A - Media for immobilizing heavymetal and method for treating water using the same - Google Patents

Abstract

PURPOSE: A carrier for immobilizing heavy metal and a method for treating water using the same are provided to simultaneously use an immobilizing technique and an absorbing technique, thereby immobilizing heavy metal with high efficiency. CONSTITUTION: An organic matter is removed from an animal bone. The animal bone is dried at 100~120°C. The animal bone is crushed into powder of 0.21~0.425mm. A foreign material is removed from peat. The peat is dried at 100~120°C. The peat is crushed into powder of 0.21~0.425mm. A carrier is manufactured by mixing the crushed animal bond with the crushed peat. The animal bone and the peat are mixed at the mass ratio of 1:1.5~3:0.5.

Description

Heavy metal stabilization carrier and water treatment method using the same {MEDIA FOR IMMOBILIZING HEAVYMETAL AND METHOD FOR TREATING WATER USING THE SAME}

The present invention relates to a carrier for stabilizing heavy metals and a water treatment method using the same. More specifically, the present invention relates to a carrier for stabilizing heavy metals having excellent efficiency, economical and environment-friendly, and a water treatment method using the same.

Research and development of heavy metal removal techniques in groundwater began in developed countries in Europe, and now various researches are being conducted in the US, and dozens of materials and applied technologies have already been established through systematic environmental policy and capital investment in developed countries. This situation is being developed.

Conventional treatment methods mainly used to remove heavy metals in water include chemical flocculation precipitation, ion exchange, liquid membrane, adsorption, and solidification.

Chemical precipitation is currently the most used heavy metal treatment technology and is economical for the treatment of high concentration heavy metal containing waste. Although chemical precipitation is relatively simple and economical, it is difficult to recover due to the lack of selectivity for heavy metals. In one example of chemical precipitation, a large amount of alkali, such as ammonia water and slaked lime, is added to the water and the pH of the solution is raised to 10 or higher, forming hydroxides of heavy metal ions. At this time, the solubility is affected by the concentration of metal ions in the wastewater, pH, and the like, and is easily precipitated in the order of Fe> Al> Cu> Zn> Ni> Pb> Cd> Mn according to the type of metal. The law is not suitable for the removal of Pb, Cd, which is a major problem in wastewater treatment. Therefore, the wastewater treated by the sedimentation method can often lower the heavy metal concentration below the regulatory value only by reprocessing such as adsorption, membrane separation, and ion exchange.

Ion exchange is a well known technique and is widely used for water softening and purification. Ion exchange has proven to be a very efficient technique for heavy metal removal. The ion exchange method is used for tertiary treatment or final treatment prior to discharge or recovery of valuable metals such as silver and chromium. However, the ion exchange resin has a disadvantage in that it is not sufficiently selective for metal ions. In addition, when industrial water is produced from tap water or groundwater, a large amount of calcium ions or magnesium ions are ion-exchanged by ion-exchange resins, which is inefficient considering the economics of ion-exchange resins.

The liquid film method has attracted attention as a new heavy metal removal and recovery technique due to the increase in selectivity to metal ions and an increase in separation rate. Separation by liquid membranes is characterized by very high selectivity and concentration for ions. This is a fast extraction speed, extraction and back extraction can be carried out simultaneously by a single process, solutes can be selectively separated and concentrated in high concentration, the support of the membrane is not necessary, and the membrane itself can be regenerated or reused. Have. However, the liquid film method has a disadvantage in that swelling and fracture of the liquid film occur.

Compared to liquid membranes, solid polymer membranes have much higher stability and easy separation process, but have a slower permeation rate of ions and insufficient ability to selectively separate and transport only specific substances by identifying permeable substances such as liquid membranes. In order to obtain a solid polymer membrane having a selective separation function of heavy metal ions, the polymer membrane itself must have a selectivity, and for this purpose, a polymer having a selective interaction with a permeable material must be introduced into the membrane.

In addition, as a heavy metal stabilization technology, there is a technology that greatly reduces the mobility of heavy metals by injecting various phosphates to form a very stable insoluble compound with heavy metals. Minerals produced by reacting with lime change solubility greatly in the environment such as pH, but minerals produced by reacting with phosphorus have very low solubility without being affected by environmental changes such as pH. Due to these advantages, the technology for restoring the ground and groundwater contaminated with heavy metals using phosphorus (P, phosphorus) has attracted much attention. Phosphorus is present in the form of various phosphates (Ca, K, Na), phytate, or apatite, by replacing the heavy metals with these metal ions to form new pyromorphite strains with very low solubility. The heavy metal is fixed. However, when only phosphate is used without addition of other components, the heavy metal treatment efficiency is 80-85%, and it is difficult to lower the heavy metal concentration below the regulation level when treating groundwater or wastewater having a high content of heavy metals.

There is a continuing need in the art for the development of technologies that can process heavy metals in an efficient, economical and easy way.

In order to solve the above problems of the prior art, an object of the present invention is to provide a carrier for stabilizing heavy metals and a method for producing the same, which is excellent in efficiency, economical and environmentally friendly. In addition, an object of the present invention is to provide a water treatment method using the carrier for stabilizing heavy metals.

The present invention provides a carrier for stabilizing heavy metals including animal bones and peat.

The present invention also provides a method for preparing a carrier for stabilizing heavy metals, comprising the steps of crushing animal bone, crushing peat, and preparing a carrier by mixing crushed animal bone and crushed peat.

The present invention also provides a water treatment method using a carrier for stabilizing heavy metals according to the present invention.

The heavy metal stabilization carrier according to the present invention can stabilize the heavy metal with a very high efficiency by using the stabilization technology and the adsorption technology at the same time, it is possible to treat the heavy metal in a short time. Therefore, it can be used as a method for restoring groundwater, tunnel wastewater, landfill leachate, metal mine acid drainage, etc., contaminated with high-performance heavy metals. In addition, the process is easy and no additional components are required for the preparation. In addition, animal bone can be used in the slaughter process or food production process, and peat can be used in the natural state, it is environmentally harmless. In short, the heavy metal stabilization carrier according to the present invention is a water treatment technology that is very suitable for the domestic reality in a most economical and environmentally harmless method in time and efficiency.

Hereinafter, the present invention will be described in detail.

Heavy metal stabilizing carrier according to the present invention is characterized in that it comprises animal bones and peat.

As described above, the stabilization technology of heavy metals using phosphate has an advantage of forming a heavy metal complex having a very low solubility without being affected by environmental changes such as pH. However, the method using only phosphate does not have sufficient efficiency for treating heavy metals, and therefore, when treating water with a high concentration of heavy metals such as groundwater, the concentration of heavy metals cannot be lowered below the regulation value.

However, the present invention has found that by using animal bone and peat together, it is possible to stabilize and adsorb heavy metals at a significantly higher efficiency than the technique using phosphate and peat respectively. In other words, the present invention can achieve the effect of stabilization technology of heavy metals using phosphate by using animal bone containing natural phosphate, and at the same time by using animal bone and peat containing phosphate together without using phosphate alone. The synergistic effect can maximize the stabilization and adsorption efficiency of heavy metals.

Specifically, using the carrier for stabilizing heavy metals according to the present invention, the adsorption of peat and heavy metals that can be obtained in a natural state while at the same time the chemical precipitation of PO ₄ ^3- and or apatite and heavy metal ions of the animal bone occurs Or a complexation is formed. That is, according to the present invention, a technique of forming a very stable insoluble compound of heavy metals using phosphate eluted from animal bone and a technique of adsorbing heavy metals using peat having excellent adsorption capacity can be used at the same time. Can produce synergistic effects. Therefore, according to the present invention, the reaction occurs in a faster time than the removal of heavy metals only with the existing phosphate and the removal rate is increased.

Therefore, when the carrier according to the present invention is treated with water having a high concentration of heavy metals such as groundwater, metal mine drainage, tunnel wastewater, and leachate, the concentration of heavy metals can be treated within a very short period.

In addition, in the present invention, animal bones generated during the slaughter process or the food manufacturing process can be used through pre-treatment if necessary, and peat can also be used in the natural state, so that the environment is prepared even during the preparation of the material or after the water treatment. Harmless to In addition, the use of animal bones makes it easy to form carriers with peat without additional components. If additional components are added in addition to the active ingredients necessary for stabilizing heavy metals to form the carrier, not only is the manufacturing process uneconomical, but there is also a risk of further contamination by the additional components in the water treatment. Therefore, the heavy metal stabilization carrier according to the present invention is environmentally harmless, and can be said to be a treatment technology suitable for domestic reality as the most economical method in terms of time and efficiency.

Porcine bone, tuna bone, etc. may also be used as the animal bone, but it has been found that the bovine bone is particularly useful in the present invention. Specifically, the bovine bone has the highest total phosphorus concentration compared to the bones of other animals, and is superior to the bones of other animals in terms of phosphate dissolution rate and dissolution rate relative to the amount used. The present inventors measured total phosphorus (TP), apatite phosphorus (AP), non apatite inorganic phosphorus (NAIP), organic phosphorus (IP), and organic phosphorus (OP) on available animal bones. Shown in

Classification Bovine bone Pork bone Tuna Bone TP (Total phosphorus) 1190.6 925.1 873.0 Apatite phosphorus 962.7 775.8 546.5 Non apatite inorganic phosphorus (NAIP) 61.3 62.5 34.3 Inorganic phosphorus 1072.2 856.5 689.2 OP (Organic phosphorus) 83.3 55.8 153.8

In the present invention, the animal bone is preferably crushed and added to the particle size of 0.21mm to 0.425mm. The smaller the particle size of the animal bone, the higher the dissolution rate and dissolution rate of the phosphate from the animal bone. However, in the case of a certain size or less, the difference in dissolution rate and dissolution amount is not large and the cost of crushing increases. Particle size ranges are preferred.

The animal bone is preferably a state in which organic matter and water are removed. Preferably, the animal bone has a water content of 5% or less.

In the present invention, peat collected at K point can be used. Peat is also preferably crushed to a particle size of 0.21mm to 0.425mm. By preparing peat in the particle size in the above range, the animal bone and peat can be uniformly mixed in the carrier.

The content of animal bone and peat in the carrier according to the present invention is preferably in a mass ratio of 1: 1.5 to 3: 0.5, more preferably in a mass ratio of 1: 0.5.

The shape and size of the carrier for stabilizing heavy metals according to the present invention are not particularly limited and can be determined by those skilled in the art according to the intended water treatment application. For example, it may be in powder or pellet form, and the size may be 0.2-0.825 mm in particle size, but is not limited thereto.

The method for preparing a heavy metal stabilizing carrier according to the present invention includes the steps of crushing animal bone, crushing peat, and mixing the crushed animal bone and crushed peat to prepare a carrier.

Animal bones such as cattle bones can be collected and used at restaurants and slaughterhouses. Animal bone is preferably broken into powder having a particle size of 0.21 mm to 0.425 mm. Peat can be collected from point K. Peat is also preferably crushed to a particle size of 0.21mm to 0.425mm. The shredding method may use a method known in the art.

Animal bone and peat is preferably contained in the carrier by mixing in a ratio of 1: 1.5-3: 0.5, more preferably in a carrier by mixing in a ratio of 1: 0.5 by mass.

The method for producing a heavy metal stabilizing carrier according to the present invention preferably further comprises the step of removing the organic matter from the animal bone, and drying the animal bone before crushing the animal bone.

Removing the organics from the animal bone is to increase the purity of the components required for stabilization of heavy metals, and to prevent further contamination of water by the residual organics during water treatment.

The animal bone is preferably dried at 100 ° C to 120 ° C, more preferably at about 105 ° C. Moisture can be removed by drying at 100 ° C or higher. In addition, drying at high temperatures in excess of 120 ° C may lead to a change in the apatite form of phosphorus in the bones of animals, which may affect the phosphate elution amount and rate.

The method for preparing a heavy metal stabilizing carrier according to the present invention may further include removing foreign matter from peat and drying the peat before crushing the peat.

In the step of removing foreign matter from peat, a method known in the art may be used, such as washing with a liquid such as water. By removing the foreign matter in this way, it is possible to increase the purity of the components required for adsorption of heavy metals, and to prevent further contamination of water by the foreign matter during water treatment.

The peat is preferably dried at 100 ° C to 120 ° C, more preferably at about 105 ° C. Moisture can be removed by drying at 100 ° C or higher. In addition, when drying at a high temperature of more than 120 ℃ may cause a change in the humic acid and organic matter in peat may lead to a decrease in the adsorption capacity of heavy metals.

The present invention also provides a water treatment method using a carrier for stabilizing heavy metals according to the present invention. According to the water treatment method according to the present invention, it can be carried out by administering the above-described heavy metal stabilizing carrier to the water to remove the heavy metal, but is not limited thereto, it is possible to use a method known in the art. In addition, the throughput can also be determined by one skilled in the art depending on the nature of the water to be treated or the concentration of heavy metals. As a method of water treatment using the carrier according to the present invention, for example, a column reactor, a CSTR reactor can be used, and the reactor can be selected according to the daily treatment capacity.

When treating water with a heavy metal concentration of 50 mg / L or less, when using a column reactor, the daily treatment capacity is 1,000 m ³ / day or less, and the column reactor EBCT is 2-4 hours; If the CSTR reactor is used, the daily treatment capacity is more than 1,000 m ³ / day and the CSTR reactor HRT is 3-6 hours. When using the carrier according to the invention the heavy metal removal efficiency is 95% or more can satisfy the groundwater and river effluent standards.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are intended to illustrate the present invention, and are not intended to limit the scope of the present invention by these.

Example 1

The experiment was carried out by mixing a 200 mL Pb solution with a carrier of 1.33 g of bovine bone and 0.67 g of peat (2 g in total, mixing ratio of bovine bone and peat 1: 0.5 by weight). At this time, the bone was prepared by removing the organic matter and dried at 105 ℃ and crushed to a particle size of 0.21mm to 0.425mm. The peat was prepared by drying at 105 ° C. collected at K point and crushing to a particle size of 0.21 mm to 0.425 mm. The removal efficiency of Pb was used in the column reactor shown in FIG.

Comparative Example 1

The experiment was conducted in the same manner as in Example 1, except that 2g peat was used instead of a mixture of 1.33g bovine bone and 0.67g peat (2g total).

Comparative Example 2

The experiment was carried out in the same manner as in Example 1 except that 2g bovine bone was used instead of a mixture of 1.33g bovine bone and 0.67g peat (2g total).

Experimental results of Example 1, Comparative Example 1 and Comparative Example 2 are as shown in FIG.

According to FIG. 3, Example 1, Comparative Example 1 and Comparative Example 2 showed a significant difference in Pb removal efficiency even though the same amount (2 g) of stabilizer was used. In other words, when bone or peat is used alone, the effect of the present invention cannot be achieved even if the amount of use is increased. From the experimental results, it can be seen that in the present invention, by using the bone and peat together, the heavy metals can be removed with very high efficiency in a very short time due to the synergistic effect of their interaction.

Example 2

The experiment was carried out in the same manner as in Example 1, except that a carrier having a mixing ratio of bovine bone and peat was 0.5: 1 in weight ratio.

Example 3

The experiment was carried out in the same manner as in Example 1, except that a carrier having a mixing ratio of bovine bone and peat was used in a weight ratio of 1: 1.

Experimental results of Examples 1 to 3 are shown in FIG. 4. According to the mixing ratio of animal bone and peat, the concentration of heavy metal Pb was the smallest when the mixing ratio (weight ratio) of bovine bone and peat was 1: 0.5.

1 is a cross-sectional photograph of a support for stabilizing heavy metals according to an embodiment of the present invention.

2 is a schematic view of a column reactor used to evaluate the water treatment effect of the support for stabilizing heavy metals in Examples and Comparative Examples.

3 is a graph showing the heavy metal removal efficiency according to Example 1, Comparative Example 1 and Comparative Example 2.

Figure 4 is a graph comparing the Pb concentration change according to the mixing ratio of the bone and peat of the animal according to Examples 1 to 3.

Claims (16)

Carrier for stabilizing heavy metals including animal bones and peat. The support for stabilizing heavy metals according to claim 1, wherein the animal bone is bovine bone. The support for stabilizing heavy metals according to claim 1, wherein the animal bone is added by being crushed to a particle size of 0.21 mm to 0.425 mm. The method of claim 1, wherein the animal bone is a carrier for stabilizing heavy metals that organic matter and water is removed. The support for stabilizing heavy metals according to claim 1, wherein the peat is added by being crushed into a particle size of 0.21 mm to 0.425 mm. The method of claim 1, wherein the animal bone and the content ratio of the peat is a heavy metal stabilizer of the mass ratio 1: 1.5 to 3: 0.5. Crushing animal bones, Crushing peat, and Preparing a carrier by mixing the crushed animal bone and the crushed peat Method for producing a heavy metal stabilization carrier comprising a. The method of claim 7, wherein the step of crushing the animal bone is a method of producing a carrier for stabilizing heavy metal stabilizing the animal bone to a particle size of 0.21mm to 0.425mm. The method of claim 7, wherein the pulverizing the peat is a method for producing a heavy metal stabilization carrier to crush the peat to a particle size of 0.21mm to 0.425mm. The method of claim 7, further comprising removing organic matter from the animal bone, and drying the animal bone before crushing the animal bone. The method of claim 10, wherein the drying of the animal bone is performed at 100 ° C. to 120 ° C. 12. The method of claim 7, further comprising drying the peat prior to crushing the peat. The method of claim 12, wherein the drying of the peat is carried out at 55 ℃ to 70 ℃ manufacturing method for a heavy metal stabilization carrier. The method of claim 7, wherein the animal bone and the peat are mixed in a mass ratio of 1: 1.5 to 3: 0.5. Water treatment method using a carrier for stabilizing heavy metals according to any one of claims 1 to 6. The water treatment method according to claim 15, wherein the concentration of heavy metal in water is 50 mg / L or less.

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