KR100706764B1 - Remove column of heavy metal using a starfish treated by enzyme - Google Patents

Abstract

The present invention relates to a column for adsorbing heavy metal ions, and more specifically, to extracting porous calcium carbonate from starfish by proteolytic digestion, and to filling with calcium carbonate, heavy metal using enzyme-treated starfish extract The column for adsorption shall be a technical subject matter. Accordingly, it is excellent for the purification of heavy metals, and helps to clean up and preserve marine and river ecosystems, and contributes to the increase of income of farmed fishers, and to reduce heavy metal removal facilities and maintenance costs of factories that produce heavy metals. It is greatly helpful, and also after the heavy metal is adsorbed through a separate process to remove only the heavy metal adsorbed, there is an advantage that the cost can be reduced.

Enzyme Protein Starfish Extract Column Heavy Metal

Description

Remove column of heavy metal using a starfish treated by enzyme}

Figure 1a-SEM image of calcium carbonate, a starfish extract according to the present invention.

1b-SEM image of calcium carbonate, a starfish extract by conventional heat treatment.

Figure 2-XRD pattern of calcium carbonate, a starfish extract according to the present invention.

Figure 3a-Figure showing the adsorption removal rate for each heavy metal of calcium carbonate starfish extract according to the present invention.

Figure 3b-Figure showing the adsorption removal rate of heavy metals by concentration of calcium carbonate starfish extract according to the present invention.

Figure 4 is a diagram showing the adsorption removal rate of heavy metal ions with respect to the pH of the aqueous solution of heavy metal salt in calcium carbonate, which is a starfish extract according to the present invention.

Figure 5 is a diagram showing the adsorption removal rate of heavy metal ions with respect to the duration in the column packed with calcium carbonate starfish extract according to the present invention.

Figure 6 is a diagram showing the adsorption removal rate of heavy metal ions with respect to the temperature of calcium carbonate, which is a starfish extract according to the present invention.

Figure 7a-Figure showing the reprocessing efficiency according to the concentration of NaOH of calcium carbonate as a starfish extract according to the present invention, Figure 7b-Figure showing the reprocessing efficiency according to the concentration of HNO ₃ .

The present invention relates to a column for adsorption of heavy metal ions, and more particularly to a column for adsorption of heavy metals using an enzyme-treated starfish extract packed with calcium carbonate extracted from starfish using proteolytic enzymes.

Entering the 21st century, pollutants due to population growth, urbanization and industrialization are increasing. In particular, water pollution is increasing, and heavy metal contamination is the most serious condition, and urgent measures are required. Accordingly, more economical and efficient environmental preservation and pollution prevention measures are needed, and many studies have already been conducted to prevent damage to human body accumulation and bioconcentration of heavy metals.

Conventionally, the technology to remove the existing heavy metals by one step is enhanced to exist in waste resources such as volcanic stone, fly ash, zeolite, clay, loess, shellfish, humic acid, seaweed waste and waste paper cup or cheap and easily available nature. The use of materials to identify or eliminate contamination is being activated.

Recently, technology that removes heavy metals using starfish is economical and natural. Starfish that live in offshore waters are adversely affecting marine ecosystems, reducing farm yields, and are only a headache for fishermen and are looking for ways to use them as another resource. These starfish are currently dried and sprinkled on farmland to be used in part to increase the harvest or to be used in the manufacture of fertilizers of calcium carbonate.

However, the composition of the starfish is mainly a large amount of protein and calcium carbonate, but the use method is very low, and the heavy metal removal technology using the starfish is being studied.

As a technique for removing heavy metals using conventional starfish, Korean Patent Application Publication No. 2003-0035367 "Heavy Metal Removal Agent Using Starfish" is known. This is a starfish dried for about 1 to 3 hours in a dryer adjusted to 60 to 120 degrees Celsius, and then incinerated at 400 to 700 degrees Celsius, and then crushed to form a certain size, which is a heat treatment of the starfish The organic component is removed and the inorganic component is left. Heavy metal adsorption and removal performance is not so high.

The present invention has been made by the above necessity, by extracting the calcium carbonate component in the starfish by proteolytic enzymes to adsorb heavy metals, to provide a heavy metal adsorption column using an enzyme-treated starfish extract to remove heavy metals while preserving the ecosystem For that purpose.

In order to achieve the above object, the present invention, by extracting the porous calcium carbonate from the starfish by proteolytic enzyme decomposition, the column for adsorption of heavy metals using the enzyme-treated starfish extract, characterized in that the calcium carbonate packed in a fixed phase To be a technical point.

In addition, HNO ₃ after heavy metal adsorption of the column The solution is preferably added to remove only the heavy metal adsorbed from the calcium carbonate packed in the column, and the calcium carbonate may be reused.

As a result, it is excellent in the purification of heavy metals, not only helps to clean up and preserve marine and river ecosystems, but also contributes to the increase of income of farmed fishers, and greatly reduces the heavy metal removal facilities and maintenance costs of factories that generate heavy metals. Also, after the heavy metal is adsorbed, only the heavy metal adsorbed through the separate treatment process can be removed and reused, thereby reducing the cost.

In the present invention, an appropriate amount of starfish collected from the lotus root coast is put in a water bath, distilled water is poured, proteolytic enzymes are added, and soaked for a predetermined time in an electrostatic water bath at a predetermined temperature. This method is repeated at least five times to extract a large amount of components from the starfish.

As a result, a protein component, which is an organic component of the starfish, is formed at an upper portion of the tank, and a calcium carbonate (CaCO ₃ ) component having a specific gravity greater than that of water, which is an inorganic component of the starfish, is light yellow. It will sink.

The sunken material is collected, heated for a predetermined time, and dried sufficiently in the shade to obtain white calcium carbonate granules. As shown in FIG. 1A, when the SEM photograph (300 times and 1000 times magnification, respectively) of the starfish extract according to the present invention is examined, it can be seen that the pores are not uniformly destroyed and uniform.

However, as shown in FIG. 1B, the calcium carbonate extracted through carbonization and incineration at 500 ° C., which is a conventional method of heat treatment, has no porosity, and thus almost no porosity. Thereby, calcium carbonate, which is a starfish extract by enzymatic decomposition according to the present invention, is expected to have excellent adsorption capacity.

When the calcium carbonate granules are added to an appropriate amount of a column, a column for adsorption of heavy metals using the enzyme-treated starfish extract according to the present invention is completed, and when a heavy metal solution is poured into the column, the heavy metal component is adsorbed onto the calcium carbonate. Heavy metals can be removed.

In addition, HNO _{3 in the} calcium carbonate adsorbed heavy metal When the solution is mixed, only the heavy metal adsorbed from the calcium carbonate is removed by the ionic reaction, and the calcium carbonate can be reused, thereby reducing the cost of starfish processing.

Hereinafter will be described for the preferred embodiment of the present invention.

Example

Of calcium carbonate from starfish  extraction

The appropriate amount of starfish collected through Gijang-gun fishing village was placed in a 2L glass tank, 1,000 ml of distilled water was poured, 10 g of proteolytic enzyme was added (pH = 7), and then placed in an electrostatic bath and maintained at 45-50 ° C. This method was repeated five times to extract a large amount of components.

As a result, the protein component of the starfish is formed in the upper part of the tank, and the calcium carbonate component in the lower part has a specific gravity greater than that of water, so that it can be seen as a light yellow and settled material, which was collected and heated in boiling water for about 10 minutes. After heating, the mixture was sufficiently dried in the shade to obtain a white calcium carbonate.

Hydrolysis reaction by proteolytic enzyme is as follows. As this process changes to the form of amino acids, dipeptides, peptides, only the bone fragments in the starfish body is released, resulting in calcium carbonate.

In order to identify the components of the starfish, the results of the component analysis after combustion are shown in Table 1.

Table 1.

Composition Humidity Inorganic Mat. Organic Mat. Nitrogen Ester Carboxyl acids L.O.I 67.3 32.3 13.9 10.0 3.7 0.2 18.3

As shown in Table 1, it can be seen that except for the water is composed of a protein component and an inorganic material. The mineral content of minerals is about 30%, which translates into about 76% of calcium carbonate. can see.

Reagents and Instruments

The heavy metals used in the heavy metal adsorption experiment used in this example were copper (CuCl ₂ 2H ₂ O), lead (Pb (NO ₃ ) ₂ ), cadmium (Cd (NO ₃ ) ₂ ), and chromium (K ₂ Cr ₂ O ₇ ) and zinc (ZnCl ₂ ) were prepared by concentration. Heavy metal ionic solutions are CuCl ₂ 2H ₂ O, Cd (NO ₃ ) ₂ , Pb (NO ₃ ) ₂ , K ₂ Cr ₂ O ₇ , ZnCl ₂ The reagents are prepared, and mixed with distilled water using an electronic balance to prepare precisely at concentrations of 1 ppm, 3 ppm, 5 ppm, 10 ppm, and the like. A buffer solution was prepared and used to determine the ability of the filtration adsorption treatment according to pH.

In addition, the adsorption column was prepared by acryl cylinder tube of diameter 30mm length 500mm, attaching the coating network to the lower part, and then attached to the safety coke to be fixed, and the injection of heavy metal wastewater on the cylinder tube is well made.

The instrument used for analysis was ICP (Thermo Jarrell As, ICP-IRIS), SEM / EDX (HITACHI, S-4200), XRD (Rigaku, Rigaku Model D / Max-2400), Measurements were made using XRF (Philips PW 2400).

Heavy metal filtration and adsorption removal experiment using adsorption column

5 g of starfish calcium carbonate granules are weighed and placed in a filtration and adsorption column. The residual amount of heavy metal after filtration and adsorption according to the column residence time (ECBT) when 5 g of starfish calcium carbonate is used is measured by ICP.

By the number of times, the concentration of the heavy metal salt solution, the experiment temperature, pH to make a buffer solution according to the change of removal rate is measured.

Calcium Carbonate of Starfish characteristic

X-ray diffraction (XRD) analysis was performed to identify particles extracted from starfish using proteolytic enzymes, and is shown in FIG. 2. As shown in FIG. 2, it was identified as calcium carbonate in exact correspondence with calcium carbonate in the JCPDS card.

The mechanism of calcium carbonate to which heavy metal ions are adsorbed is as follows. Known structures of calcium carbonate are triangular structures of each CO ₃ ^{2 −} that form a layer and lie perpendicular to the central axis c-axis. Meanwhile Ca ^{2 +} layer is located above, CO ₃ ² of ^under-shared with the oxygen of the structure of the triangle, and has a structure because of the space to create a form octahedral maintain large shape compared to the other compounds. Mechanisms that are adsorbed in this structure is determined to a very high removal ability of the heavy metal to heavy metals or their ions Ca ^{2 +,} instead of ion-exchanged by the substituted or effect of adsorption on the structural space on.

Comparative example -Comparison of heavy metal removal rate of various substances

Five kinds of aqueous heavy metal ions were made into 3ppm of activated carbon, crab shell, sawdust, commercially available calcium carbonate, and calcium carbonate extracted from starfish. The results for heavy metal removal rate after adsorption are shown in Table 2.

Table 2.

Filter Matrials Cu ^{2 +} CD ^{2 +} Cr ^{6 +} Zn ^{2 +} Pb ^{2 +} Activated carbon Activated carbon ) 73.30 78.83 65.06 78.13 65.96 Crab shell Crab shell ) 86.87 93.77 74.20 82.53 71.56 Sawdust ( Sawdust ) 78.60 90.80 57.60 70.56 62.13 Calcium carbonate ( CaCO ₃ ) 63.33 43.20 33.27 34.33 29.60 Starfish-Calcium Carbonate ( Starfish Calcium carbonate) 86.23 94.97 82.10 86.53 77.60

5g of each of the above substances in the filtration and adsorption column was tested for the removal of heavy metals according to the conditions. The results showed that the starfish-calcium carbonate> crab shell> sawdust> activated carbon was superior to around 80%. This showed the best removal property overall.

In addition, in order to determine the volume change of calcium carbonate obtained from activated carbon, crab shell, sawdust, commercial calcium carbonate and starfish, each of 3 g was weighed and placed in a measuring cylinder and 5 ml of distilled water was tested. The largest volume change was sawdust, and the crab shell and activated charcoal tended to have a large change, but the volume change of calcium carbonate obtained from calcium carbonate and starfish was small.

Adsorption removal rate according to heavy metal type

After the filtration and adsorption column was made using the starfish calcium carbonate extract using an enzyme, an experiment was conducted in which a heavy metal ion solution was passed.

3a shows the filtration and adsorption removal rates of heavy metals and ions in a 3 ppm heavy metal ion solution by the number of passes of the filtration and adsorption column containing 5 g of starfish calcium carbonate granules at 20 ° C. The second pass was more than 90% except for Cr and Pb, and the third average was 95%.

Figure 3b shows the residual amount and removal rate after filtration and adsorption removal of aqueous heavy metal salt solution by concentration. The removal rate of heavy metals increases as the concentration increases in the order of 1ppm <3ppm <5ppm <10ppm, but there is no difference between 5ppm and 10ppm.

4 shows a buffer solution according to pH of a 3 ppm heavy metal salt aqueous solution in a filtration and adsorption column containing 5 g of starfish calcium carbonate granules at 20 ° C., followed by three passes through filtration and adsorption and removal of heavy metals and ions. Indicated. Residual amount and removal rate were shown after 3 passes.

In the same manner, Figure 5 summarizes the residual amount and removal rate after the filtration and adsorption removal of the aqueous solution of 5ppm heavy metal salt of pH = 7 at 20 ° C temperature condition. As a result of analyzing the removal rate, there was a large difference between 3 and 5 minutes, but there was no significant difference after 10 minutes, and after 20 minutes, the removal rate reached almost 100%.

In Figure 6, the aqueous solution of 3ppm heavy metal salt was placed in a filtration / adsorption column containing 5 g of starfish calcium carbonate granules, and the removal rate was shown after three passes for each temperature condition. Other heavy metals except Cu ions showed high adsorption rate at 40 ℃ but rapidly decreased at higher temperatures. It is thought that this decrease occurs because the activity of heavy metal ions increases with high temperature, so that the adsorption power is lowered.

Starfish Calcium Carbonate Reuse method after adsorption

How to re-usable calcium carbonate granules in a continuous starfish column adsorption experiment because they contain the acid ion in the composition in the acid solution using a lot of the reprocessing method of the activated carbon used in this case a lot of CO ₂ HCl As gas is generated, the calcium carbonate component is lost and some CaO is generated, but the overall dissolution occurs, and thus the recovery rate is very low.

The basic solution is M ^{n +} + n (OH) ^- → M (OH) n reaction to remove the adsorbed heavy metals and remove the calcium carbonate of the starfish. It is believed that the component can be restored to its original state.

Thus, granules left for 5 weeks at 5M mixed aqueous solution of 5 kinds of heavy metal salts were added to 1M, 3M, 5M, and 7M HNO ₃ solutions, respectively, in a Erlenmeyer flask, and washed well under running water after 24 hours. After drying, 3ppm of heavy metal aqueous solution was tested three times at 20 ° C. through a filtration and adsorption column, and the results are shown in FIG. 7. As a result, the reprocessing efficiency of each concentration in NaOH solution was less than 18%, and the reprocessing efficiency of HNO ₃ solution increased with increasing concentration. There was almost no difference between 5M and 7M.

Therefore, the calcium carbonate to which the heavy metal is adsorbed is most efficiently by HNO ₃ , so that the calcium carbonate can be utilized again, thereby reducing the cost of starfish processing.

The present invention by the above configuration is excellent in the purification of heavy metals, not only help in the purification and preservation of marine and river ecosystems, but also contribute to the increase of income of farmed fishers, heavy metal removal facilities and maintenance costs of factories that generate heavy metals There is a significant effect on savings.

In addition, after the heavy metal is adsorbed, it is possible to remove and reuse only the heavy metal adsorbed through a separate treatment process, thereby reducing the cost of starfish treatment.

Claims (2)

A column for heavy metal adsorption using an enzyme-treated starfish extract, characterized in that the porous calcium carbonate is extracted from the starfish by protein enzymatic digestion, and the calcium carbonate is filled therein. The enzyme-treated starfish extract according to claim 1, wherein the HNO ₃ solution is added after the heavy metal adsorption of the column is used to remove only the heavy metal adsorbed from the calcium carbonate packed in the column, and the calcium carbonate can be reused. Heavy metal adsorption column using.

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