KR20100067368A - Method for purification processing waste-water contaminated with heavy metals using natural biosorbents made of macrophyte - Google Patents

Abstract

PURPOSE: A filtration method of heavy metal contamination effluent using a natural adsorbent made with Macroalgae is provided to environment-friendly the effluent with organism, and to lower costs of operation of a wastewater disposal facility with cheap costs of the adsorbent. CONSTITUTION: A filtration method of heavy metal contamination effluent comprises the following steps: washing macroalgae with distilled water and hot-air drying in 50~100°C; making dried macroalgae to a powdered state of 30~70 mesh; throwing marine algae powder(52a) by a rate of 0.1~3 weight% compared to weight of the effluent in the effluent polluted by heavy metals including arsenic; separating effluent into sludge and water by using a filter device or a cyclone separation device; and discharging only the purified water to the outside. The macroalgae is Pachymeniopsis sp.

Description

Method for purification processing waste-water contaminated with heavy metals using natural biosorbents made of macrophyte}

The present invention relates to a method for the purification of heavy metal contaminated wastewater using a natural adsorbent made of seaweed, and in particular, to contaminate powders obtained by crushing seaweed, persimmon skin or mushroom waste medium, which are easily obtained in nature, with heavy metals such as arsenic. The present invention relates to a method for purifying and treating various heavy metal contaminated wastewater, such as mine wastewater and industrial wastewater, by effectively adsorbing and removing heavy metals such as arsenic by adding to the wastewater.

Currently, in Korea and around the world, soil pollution and water pollution caused by various harmful heavy metals have emerged as serious environmental problems. As a way to solve this problem, technology to purify heavy metal-contaminated soil by washing, etc. has been developed. In the case of polluted water, technology development for actively removing heavy metal components using various adsorbents or filter devices has been actively conducted.

In Korea, soil and rivers can be contaminated with harmful substances such as heavy metals. There are many causes.In most cases, industrial wastewater discharged from various chemical plants, steel mills, and power plants in heavy chemical industry areas, and arsenic, Much of the heavy metals such as lead and chromium are eluted by mine wastewater caused by polluting soil and rivers. Since not only soil but also rivers are contaminated near the place where heavy metal pollutants are released, it is necessary to develop technology to effectively clean the water contaminated with heavy metals in order to improve the environment by properly purifying soil and water. There is.

In terms of heavy metal pollution in Korea, there are about 2,500 large and small mines in Korea, including about 1,000 metal mines, 380 coal mines, and 1,200 non-metal mines. As these mines have been abandoned or abandoned, various wastes are left unattended without proper environmental restoration facilities, which seriously affects the surrounding environment.

In particular, in the waste metal mines, mine wastes (wastestone, tailings, ore minerals, mine wastewater, etc.) discharged from mining activities such as mining, beneficiation, and smelting processes are left in the vicinity of the mines. It is lost by the plant and acts as environmental pollution source of farmland and water system downstream of mine. Contaminated soil or river water can affect crops, drinking water, and groundwater, which can harm the health of people who consume it through the food chain.

Although the environmental pollution restoration projects have been carried out in some of the waste metal mine areas in Korea, the restoration effect is very uncertain as it is mainly covering cover, simple disposal, retaining wall installation and tailing technique around tailings field.

Restoration of contaminated soil in mining or industrial areas is mainly by washing the soil with washing liquid and removing heavy metal components from the washing liquid after washing. However, although many methods have been developed to remove heavy metals contained in industrial and mine wastewater, arsenic (As) has not been effectively removed. In the mountainous region of Korea, arsenic is contained largely because of the characteristics of mother rock, and large amounts of arsenic are detected in tailings, soils and waters near metal and coal mines. Arsenic, unlike other heavy metals (lead, chromium, cobalt, copper, cadmium, and mercury), is difficult to remove using existing adsorbents, and is difficult to remove due to no precipitation at elevated pH.

Therefore, there is a great need for the development of a technology capable of effectively purifying the contaminated wastewater after washing the contaminated wastewater in the mining and industrial areas or the soil of the contaminated area and in particular removing the arsenic component from the wastewater. In addition, it was necessary to develop a new material that is inexpensive and easily available in Korea as a material (adsorbent) used to remove arsenic.

The present invention develops biological materials such as seaweeds, which are readily available in the natural world, and are inexpensive, as new natural adsorbents, and applied to industrial wastewater and mine wastewater purification processes to effectively remove heavy metal contaminants including arsenic. It is an object of the present invention to provide a method for the purification of heavy metal contaminated wastewater using natural adsorbents.

A method for purifying heavy metal contaminated wastewater using a natural adsorbent made of seaweed according to the present invention includes: washing the seaweed with distilled water and drying the hot air at 50 to 100 ° C; A second step of making the dried seaweed into a powder state of 30 to 70 mesh; A third step of adsorbing the algae powder into the wastewater contaminated with heavy metals including arsenic at a ratio of 0.1 to 3% by weight relative to the weight of the wastewater and stirring for 3 to 72 hours at a temperature of 20 to 35 ° C. step; And a fourth step of separating the waste water from which the adsorption reaction of the third step is completed into sludge and water by using a filter device or a centrifugal separator so that only purified water is discharged to the outside.

The method for the purification of heavy metal contaminated wastewater using the natural adsorbent made of seaweed according to the present invention is to develop biological materials such as seaweed, which are readily available in nature and inexpensive, as a new natural adsorbent, and are used in the purification process of industrial wastewater and mine wastewater. By applying, it is possible to effectively remove the arsenic components that were difficult to remove by the existing wastewater treatment technology, and it has the advantage of lowering the operating cost of the wastewater treatment plant by significantly lowering the purchase cost of the used adsorbent.

In addition, the method for purifying heavy metal contaminated wastewater using natural adsorbents made of seaweed according to the present invention is environmentally friendly by not using any adsorbents made of chemicals, and by utilizing biological materials that are simply discarded in the natural world, resources can be recycled. There is an advantage.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and effect of the method for the purification of heavy metal contaminated wastewater using a natural adsorbent made of seaweed according to the present invention.

The present invention relates to a method for the purification of heavy metal contaminated wastewater, but in particular the removal of arsenic components in the contaminated wastewater, the present specification describes the characteristics of arsenic and the properties of the natural adsorbent adsorbing arsenic.

1 shows a pH-pe stabilization plot of arsenic present in nature. Arsenic is a nonmetallic element found in aquatic and soil environments and is commonly found in combination with other elements. Arsenic exists in the form of AsO ₂ ^-1 in the natural aquatic environment of nature. Minerals containing arsenic vary widely, and arsenic often forms compounds with metals such as lead, silver and tin and is present as a compound combined with iron, nickel and sulfur. Arsenic is often concentrated in Fe minerals and sulfur compounds such as FeAsS (Arsenopyrite or Mispickel), As ₄ S ₄ (Realgar) and As ₂ S ₃ (Orpiment).

Arsenic is divided into inorganic arsenic and organic arsenic. Organic arsenic means that arsenic is combined with carbon and hydrogen, mainly in the form of Cocodylic Acid (Dimethylarsenic Acid or DMA) in the soil and sometimes as a trace component of many foods. Inorganic arsenic has a greater adverse effect on human health, with the most common inorganic arsenic being trivalent arsenic (trivalent arsenic, Arsenite, arsenite) and pentavalent arsenic (Arsenate). It exists in form. In other words, arsenate is the main species in oxidized environmental conditions, and arsenite is the main form in reduced environmental conditions.

As shown in the pE-pH stabilization chart shown in Figure 1 can be predicted the species species of arsenic present in various pH conditions and redox conditions (Redox). In the pH range of most waters, H ₂ AsO ₃ ⁻ (pentavalent arsenic) forms are present in very small amounts, and the sum of H ₃ AsO ₃ and H ₂ AsO ₃ ⁻ is trivalent arsenic.

Fig. 2 shows the contents of each harmful heavy metal as a result of the topsoil analysis of the soil near the Dongmyung mine, and Fig. 3 shows the contents of each of the harmful heavy metals as a result of the soil analysis of the soil near the Dongmyeong mine. As a result of analysis of each soil depth, the presence of each harmful heavy metal is indicated.

Purification of heavy metal-contaminated wastewater using natural adsorbents such as algae according to the present invention by investigating the soil contamination level in the soil contaminated with heavy metals including arsenic, and performing the washing and removal of heavy metals from the wastewater The effectiveness of the treatment method can be verified. For this reason, the inventors of the present invention directly investigated the soil contamination of the Dongmyeong mine area located in Jeongseon-gun, Gangwon-do, and the results of the investigation are shown in FIGS.

Figure 2 is a result of analyzing the heavy metal content in the agricultural soil, tailings yard soil and waste-rock yard soil in the Dongmyeong mine area. Sampling density of soil samples was collected per 900㎡ of topsoil. A total of six samples from the topsoil samples in the mining area were analyzed, and as a result, arsenic (As) showed a concentration of 8.6 ~ 291.5 mg / kg, which is a concern standard (6 mg / kg) and measures standard (15 mg). / kg) up to 50 times more than it was confirmed that a serious contamination state. On the other hand, the concentration of zinc (Zn) ranged from 54.2 to 320.1 mg / kg, but only sample 4 exceeded the standard of concern, and was determined not to be serious. In the case of arsenic, the reason for the high concentration in the topsoil is that it is highly likely that contaminated soils in the subsoil were moved artificially to the topsoil.

The subsoil analysis results shown in FIG. 3 were taken at the same positions as when the topsoil was collected in FIG. 2, but were collected at depths of 0.3 m, 0.6 m, 1 m, 2 m, and 3 m, respectively. A total of six analyzes of subsoil samples in the Dongmyeong mine area were conducted. As a result, copper (Cu) showed a concentration of 1.7 to 60.2 mg / kg, resulting in sample 6 exceeding the standard of concern, and cadmium (Cd). The concentration of was in the range of 0.3 to 8.6 mg / kg, indicating that the concentration of sample 4 exceeded the standard of concern and countermeasure. In particular, arsenic (As) has a concentration of 0.6 ~ 193.3 mg / kg, up to 30 times more than the concern (6 mg / kg) and measures (15 mg / kg) (samples 4, 5, 6) It seemed to be in serious contamination condition.

Referring to the results of the contamination analysis by depth of the Dongmyeong mine shown in FIG. 4, the concentration of arsenic contamination exceeded the standards of concern and countermeasures up to 20 times or more. It was very serious and urgent cleansing measures were needed.

FIG. 5 is a process diagram of a contaminated soil washing and purification facility in which a method for purifying heavy metal contaminated wastewater using a natural adsorbent made of seaweed according to the present invention is realized, and FIG. 6 is a detailed configuration diagram of the wastewater treatment tank 10 of FIG. .

5, the soil cleaning and cleaning facility shown in FIG. 5 includes a primary transport means 1 for transporting soil 1a contaminated with harmful metal heavy components to the hopper 2, and a primary washing tank 3a. ) Washing water storage tank (4) for storing the input hopper (2), washing water (mainly using HCl solution) and supplying the washing water to the primary washing tank (3a) and secondary washing tank (3b) through the pump (4a) , Soil component purified by dewatering the contaminated water sludge (5) of the primary washing tank (3a) and the secondary washing tank (3b), the primary washing tank and the secondary washing tank (3a, 3b) to wash the contaminated soil with washing water (7a) and the drum screen (6) to be separated into the waste water, the secondary transport device (7) for transporting the purified soil (7a), wastewater storage to remove heavy metal components such as arsenic by using a natural adsorbent to the contaminated wastewater and It consists of a processing means 10.

The wastewater storage and treatment means 10 is composed of a facility such as a tank for treating wastewater. As a preferred example, as shown in Figs. 5 and 6, the wastewater storage tank 11, the adsorption reaction tank 12 And a purified water tank 13 is connected. Wastewater supplied from the drum screen 6 flows into the wastewater storage tank 11 and is stored therein, and the wastewater in the wastewater storage tank 11 moves to an adjacent adsorption reaction tank 12. In the adsorption reaction tank 12, an adsorbent 12a composed of a new biological material developed as a natural adsorbent in the present invention, such as persimmon bark, algae, mushroom waste medium, etc., is introduced into the adsorption reaction tank 12. 12a) Adsorb harmful metals such as arsenic and cadmium in this wastewater by physical and electrochemical adsorption reaction mechanism. The adsorption reaction tank 12 and the purified water tank 13 next to it are connected through the porous permeable walls 10a and 10b formed with small holes (perforations 10c and 10d), so as to adsorb the heavy metals and thus the particle size. The larger adsorbent 12a does not pass through the through holes 10c and 10d of the permeable walls 10a and 10b, and only the purified water component moves to the purified water tank 13. The water accumulated in the purified water tank 13 is discharged through the discharge port 13b, and the water may be discharged to the outside, and may be recycled back to the wash water storage tank 4 as shown in FIG.

On the other hand, if the adsorbent components in the adsorption reaction tank 12 are already adsorbed heavy metal and can no longer proceed with the adsorption reaction is discharged through the outlet (12b), the discharged heavy metal agglutination wastewater slurry is a separate dehydration device ( 14) is separated into water and heavy metal adsorption solids, and the solid component is fixed in a form that is not harmful to the environment through a solidification stabilization process. The water discharged from the dewatering device 14 is preferably returned to the wastewater storage tank 11 to undergo a water treatment process again.

5 and 6, reference numeral 11a is a wastewater inlet of the wastewater storage tank 11, and 12c is an adsorbent inlet 12c for introducing the adsorbent 12a into the adsorption reaction tank 12.

Using the contaminated soil washing and purification equipment shown in Fig. 5, the soil of the area contaminated with heavy metal harmful substances is washed out with heavy metal component particles using a washing liquid, and the heavy metal component present in the washed liquid is developed in the present invention. It can be filtered by flocculation and adsorption using one natural adsorbent. In particular, the natural adsorbents developed in the present invention are such as algae, persimmon shells and mushroom waste mediums naturally present in the ecosystem, and can be obtained at a low price, and above all, those that were previously discarded as trash can be recycled as adsorption materials. In terms of nature recycling and environmental protection is also a big advantage.

Figure 7 shows the experimental data on the removal effect of arsenic according to the washing operation time when the soil contaminated with arsenic. The concentration of arsenic was calculated by random sampling of contaminated soils in the Dongmyeong mine area, and the field experiment was conducted by performing two cycles of the soil washing process in the contaminated soil washing and purification facility according to FIG. As a result of the field experiments, the concentration of arsenic in the first sampled soil was 213.5 mg / kg, but as the result of the first soil washing process, the concentration of arsenic in the soil dropped to 62.6 mg / kg. The effect of reducing the concentration could be confirmed. However, this figure is also far exceeding the standard values of the soil pollution concern standards and countermeasures standards set by the Ministry of Environment, so it was necessary to perform the washing process once more. As a result of measuring the concentration of arsenic in the soil after two washing processes, the result was lowered to 5.04 mg / kg, and the results were satisfied with the soil pollution standards and measures. Compared with the initial arsenic contamination concentration value, the arsenic removal effect was about 97%. Therefore, the soil contaminated with arsenic can be effectively cleaned by introducing a washing process.

In order to effectively remove the harmful metals such as arsenic from the effluent of the contaminated soil or leachate of the mine, an adsorbent or a medium that can be easily reacted and extracted with heavy metals such as arsenic is required. There are various forms of organics and microorganisms in the environment we live in. In particular, organics exhibit various reaction patterns with pollutants such as heavy metals due to their inherent structural and chemical properties.

Adsorption reaction using biological material among organic materials can be called a biosorption mechanism in which metal ions are adsorbed by various functional groups present in the cell wall or constituent of the viscous layer of a specific organism. In this case, the cell wall or the viscous layer component acts as a kind of ion exchanger and reversibly binds to a specific metal component. Since the adsorption selectivity for metals varies from organism to organism, the search for species in Korea with specific adsorption capacity is very important in terms of the development of new biological materials. The inventors of the present invention conducted the adsorption reaction experiments on various species for the development of new biological materials, and as a result, the algae, persimmon bark and mushroom waste medium showed excellent adsorption reactions with heavy metal ions such as arsenic. Found. In particular, the present application describes a method of adsorption and removal of harmful heavy metal materials such as arsenic using a natural adsorbent made of seaweed.

FIG. 8 is a photograph of a state in which algae used in a method for purifying heavy metal-contaminated wastewater according to the present invention grows on a beach in the east coast, and FIG. 9 is a photograph of a state in which the alga of FIG. 8 is dried and crushed. FIG. 10 is a photograph of a pulverized state after drying persimmon peel (gampi) which can be used as another natural adsorbent in connection with the present invention.

8 shows a situation in which the seaweed 52 exists near the rock 51 in the sea 50 on the east coast beach. The algae 52 developed and used as a natural adsorbent in the present invention is one of the brown algae native to the east coast of Gangwon-do (collectively referred to as Pachymeniopsis sp.). Algae, such as Pakimenopsis, have the property of easily adsorbing reactions with metal ions in the form of MO ₂ ^-1 (where M is a metal atom). Adsorption with (AsO ₂ ^-1 ).

Seaweeds (Pakimenopsis) used in the experiments of the present invention were collected on the east coast near Gangneung and Gonghyeonjin, Gangwon-do, and was collected in the depth of 1.5 ~ 5m by scuba diving in mid-November. Ordinary algae are easily found in beach reefs until early July, when sea temperatures rise, but they are collected later in the experiment.

On the other hand, persimmon peel was used in the experiment by-products generated during the production of dried persimmon in the persimmon production area.

Seaweed used in the present invention is prepared in a state suitable for use as a natural adsorbent through the following process.

1) Collect algae, wash with sterile distilled water, and then hot air dry at 50 ~ 100 ℃.

2) The dried seaweed is made into a powder state of 30 ~ 70 mesh (see Figs. 9 and 10).

As a result of the present inventors experiment, the optimum effect was obtained when the temperature of the hot air was maintained at 50 ° C. in the drying process of 1) and the particles of the powder were maintained at 50 mesh in the process 2).

Alternatively, in order for the adsorption reaction to occur more easily, it is also preferable to bulk the seaweed powder obtained in the process of 2) by applying heat to so-called frying. Bulked particles can be adsorbed with more heavy metal molecules due to the formation of numerous pores in the particles, thus increasing their specific surface area.

After the natural adsorbent using seaweed was prepared through the above process, the natural adsorbent was added to the wastewater and stirred to cause an adsorption reaction. As more natural adsorbent is added to the waste water, the adsorption reaction itself is improved, and the effect of removing heavy metal particles is increased. However, since the burden of treating the adsorbent slurry itself is increased later, it is important to adjust the amount of adsorbent in an appropriate line.

According to the inventors' experiment, it was found that the adsorption reaction was preferably carried out by adding a natural adsorbent at a ratio of about 0.1 to 3% by weight to the wastewater and stirring for 3 to 72 hours at a temperature of 20 to 35 ° C. It became. For example, 20 mL of 10 ppm heavy metal solution was added to 0.1 g of seaweed powder, stirred at 25 ° C. for 72 hours, and then filtered to measure the concentration of heavy metal remaining in the filtrate. After analysis of the content of heavy metal components present in the filtrate was measured by the ICP (Inductively coupled plasma emission spectroscopy).

At this time, the adsorption rate of heavy metal using the natural adsorbent of the present invention is calculated by the following formula.

Where q: heavy metal adsorbed per gram (g) of sample (g H.M / g biopsorbent)

v: volume of heavy metal solution used in adsorption reaction (ml)

Ci: Initial concentration of heavy metal solution (mg H.M / L)

Cf: concentration of heavy metal solution after adsorption reaction (mg H.M / L)

M: dry weight of the sample used for adsorption (g)

In the experiment of the present invention, the natural adsorbent made of seaweed can obtain the desired heavy metal removal effect or arsenic adsorption effect when 0.01-0.5 g per 20 ml of solution (pH4.5) having a heavy metal concentration of 10-100 mg / L is added. In particular, 0.1 g of a natural adsorbent per 20 ml of a solution (pH4.5) having a heavy metal concentration of 10-100 mg / L resulted in the most desirable removal of heavy metals (including arsenic).

FIG. 11 illustrates adsorption isotherm curves of arsenic when the seaweeds shown in FIGS. 8 and 9 are used as natural adsorbents to purify contaminated wastewater containing arsenic, and FIG. 12 illustrates the use of seaweeds as natural adsorbents. Experimental data on the effect of arsenic removal in the wastewater is shown by time, and FIG. 13 shows the adsorption amount of each heavy metal in the contaminated wastewater by time when seaweed is used as a natural adsorbent.

The adsorption registration curve in Fig. 11 shows the adsorption rate q calculated by the above equation of the above adsorption rate on the y axis and the equilibrium concentration on the x axis. For other heavy metals, namely cadmium, 40 mg per 1 g of pachymenopsis identified in 72 hours was adsorbed, 34.8 g for lead and 34.4 g for copper (see Figure 13). Arsenic showed Langmuir type adsorption characteristics. The maximum adsorption amount (q _max ) calculated on the basis of this result was 198.4 mg at pH 4.2 and 25 ° C., indicating that the arsenic adsorption capacity of pachymenopsis was excellent (see FIG. 11).

Wastewater generated after the soil washing process of contaminated soils has a huge adverse effect on the ecosystem if released without any treatment because of the presence of dissolved arsenic in the form of hydrochloric acid and arsenic in the raw water. Therefore, among the various methods for treating such wastewater, the wastewater treatment process was carried out using Pachymeniopsis sp. In algae, which showed an excellent effect on the treatment of dissolved arsenic.

According to the experiment of the present invention, the amount of wastewater generated by washing the contaminated soil was 5,000 liters, and the concentration of arsenic was 24.03 mg / L, which was very high compared to the effluent water quality standard (0.05 mg / L), but pakimeni After treatment with Opsis as a natural adsorbent, the concentration sharply decreased after 30 minutes, and almost no concentration of arsenic was detected after 24 hours (see FIG. 12). And the enormous amount of arsenic-free washing water was judged to be sufficiently recyclable, and it was possible to recycle it without discharging it (see Fig. 5).

On the other hand, the change in the adsorption amount of other heavy metals (cadmium, lead, copper) when using seaweed is shown in FIG. Especially in the case of lead, the adsorption efficiency was found to be excellent.

FIG. 14 is a chart showing changes in the amount of heavy metal adsorption by time when wastewater is purified by using persimmon skin and seaweed as another natural adsorbent, respectively, in accordance with the present invention. Tannin is present in the persimmon peel, which is characterized by easily adsorbing reactions with heavy metal ions.

Referring to FIG. 14, when seaweeds were used as adsorbents rather than persimmons, the adsorption and removal efficiency of arsenic was about 2 times until 12 hours and at least 10 times after 72 hours.

12 and 13, it was shown that the natural adsorbent using seaweed (Pacchimenopsis) according to the present invention has an excellent effect in removing arsenic components in the wastewater.

After the adsorption reaction has occurred as described above, the purified water is discharged to the outside (see FIGS. 5 and 6), and the natural adsorbent combined with heavy metals by the adsorption reaction is separated from the water using a filter device or a centrifugal separator device. This separated adsorbent sludge is mixed with concrete to stabilize the solidification or mixed with concrete asphalt (ascon) to solidify. Since the adsorbent sludge remaining after purifying by the present invention contains a large amount of arsenic, it is more preferable to immobilize and stabilize it in an ascon form with a very low risk of eluting rather than making it into a concrete form in which arsenic may be eluted again. something to do.

Figure 15 shows the physicochemical characteristics of the mushroom waste medium that can be used as another natural adsorbent in connection with the present invention, Figure 16 shows the state of change of the heavy metal adsorption amount by time using the waste medium.

Referring to FIG. 16, as a result of adsorbing heavy metals using waste medium, the removal rate of cadmium (Cd), lead (Pb), and zinc (Zn) excluding arsenic (As) was 99% after 30 minutes of reaction. In the case of zinc, the removal rate was maintained after 1 hour. This effect is judged to be due to the organic components (see Fig. 15) contained in the waste medium, and although not carried out in this experiment, the high molecular weight organic matter (humic acid) and fulvic acid (fulvic acid) contained in the waste medium were not carried out in this experiment. ) Is considered to be influenced by -COOH, Phenoic -OH and -OH groups. In the case of arsenic, unlike other heavy metals, the adsorption effect remained at about 97.5% in the initial 30 minutes, and showed a removal efficiency of 99.0% like other heavy metals after 1 hour of reaction time (see FIG. 16).

As described above, the method for purifying heavy metal-contaminated wastewater using a natural adsorbent made of algae according to the present invention can be easily obtained in nature and inexpensive biological materials such as algae have been developed as new natural adsorbents for industrial wastewater and mines. As it is applied to the wastewater purification process, it is possible to effectively remove arsenic components that were difficult to remove by conventional wastewater treatment technology, and to lower the cost of the adsorbent, thereby lowering the operating cost of the wastewater treatment facility. have. In addition, there is a big advantage in that it is an environmentally friendly technology by using natural organisms without using chemical adsorbents at all, and recycling previously discarded biological materials.

1 shows a pH-pe stabilization plot of arsenic present in nature.

Figure 2 shows the content of each harmful heavy metal as a result of the topsoil analysis of the soil near the Dongmyeong mine.

Figure 3 shows the present content of each harmful heavy metal as a result of the soil analysis of the soil near the Dongmyeong mine.

Figure 4 shows the content of each harmful heavy metal as a result of the analysis of the depth of the soil near the Dongmyeong mine.

5 is a process diagram of a washing and purification equipment that realizes a method for purifying heavy metal contaminated wastewater using a natural adsorbent made of seaweed according to the present invention.

6 is a detailed configuration diagram of the wastewater treatment tank 10 of FIG.

Figure 7 shows the experimental data on the removal effect of arsenic according to the washing operation time when the soil contaminated with arsenic.

FIG. 8 is a photograph of a state in which algae used in a method for purifying heavy metal-contaminated wastewater according to the present invention grows on a beach in the east coast, and FIG. 9 is a photograph of a state in which the seaweed of FIG. 8 is dried and pulverized. .

FIG. 10 is a photograph of a pulverized state after drying persimmon peel (gampi) which can be used as a natural adsorbent for the purification of heavy metal contaminated wastewater in accordance with the present invention.

FIG. 11 shows adsorption isotherm curves of arsenic when the seaweeds shown in FIGS. 8 and 9 are used as natural adsorbents to purify contaminated wastewater containing arsenic, and FIG. 12 uses algae as natural adsorbents. Experimental data on the arsenic removal effect in the waste water is shown by time, and FIG. 13 shows the adsorption amount of each heavy metal in the contaminated waste water by time when seaweed is used as a natural adsorbent.

FIG. 14 is a chart showing changes in the amount of adsorption of heavy metals over time when wastewater is purified by using persimmon skin and seaweed as natural adsorbents, respectively.

FIG. 15 shows the physicochemical characteristics of mushroom waste medium, and FIG. 16 shows the state of change of heavy metal adsorption amount by time when the waste medium is used as a natural adsorbent.

* Description of symbols on main parts of the drawings *

1: primary transport device 1a: contaminated soil

2: Input Hopper 3a: Primary Wash Tank

3b: secondary wash tank 4: wash water reservoir

4a: pump 5: contaminated water

6: drum screen 7: secondary transport

7a: Purified Soil 8: Purified Soil

10: wastewater storage and treatment tank 10a, 10b: permeation wall

10c, 10d: Permeate 11: Wastewater Storage Tank

11a: wastewater inlet 12: adsorption reaction tank

12a: adsorbent 12b: outlet

12c: Inlet 13: Septic tank

13a: purified water 13b: outlet

14: dehydrator 50: sea

51: rock 52: algae

52a: seaweed powder 53: persimmon peel powder

60: sample container

Claims (3)

First step of washing the seaweed with distilled water and hot air drying at 50 ~ 100 ℃; A second step of making the dried seaweed into a powder state of 30 to 70 mesh; A third step of adsorbing the algae powder into the wastewater contaminated with heavy metals including arsenic at a ratio of 0.1 to 3% by weight relative to the weight of the wastewater and stirring for 3 to 72 hours at a temperature of 20 to 35 ° C. step; A fourth step of separating the waste water from which the adsorption reaction of the third step is completed into sludge and water by using a filter device or a centrifugal device to discharge only the purified water to the outside; Method of purification of heavy metal contaminated wastewater using adsorbent. According to claim 1, After the fourth step, the fifth step of solidifying and stabilizing the dried solid content in the form of asphalt concrete or concrete after extracting and dehydrating the algae sludge caught in the filter device or centrifuge A method of purifying heavy metal contaminated wastewater using a natural adsorbent made of algae, further comprising the step. The method of claim 1, wherein the algae is Pachymeniopsis sp. The method for purifying heavy metal-contaminated wastewater using natural adsorbents made of seaweeds.

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