KR101605096B1 - Methode of Acid Mine Drainage Treatment using Eggshell and Microalgae Hybrid System - Google Patents

Abstract

Provided is a treatment method of acid mine drainage. The present invention relates to a process of effectively treating acid mine drainage discharged from an abandoned mine and a dormant mine. The treatment method of the present invention firstly injects waste eggshells in a powder form and neutralizes strong acid content in acid mine drainage while removing heavy metals in acid mine drainage by adsorption. When acid mine drainage is primarily neutralized, heavy metals existing in acid mine drainage is secondarily removed by a biological method while obtaining biomass at the same time. Therefore, treatment method of acid mine drainage in the present invention is performed as a hybrid-type method. In addition, the treatment method of the present invention uses domestic wastes without using chemical substances and thus is environment-friendly while having low costs.

Description

Technical Field [0001] The present invention relates to an acidic mine drainage treatment method using an egg shell and microalgae,

The present invention relates to a method of treating acidic mine drainage using waste egg shells and microalgae, and more particularly, to a method for treating acid mine drainage using waste egg shells and microalgae discharged from households, The present invention relates to a method of treating a hybrid type acidic mine drainage which is capable of efficiently removing heavy metals present in the soil and simultaneously obtaining biomass.

In Korea, the development of mines has been active in order to expand the energy demand due to the modernization of the 60s and 70s in the past. However, since the mid 1980s, the consumption pattern of energy has changed and since the 1989 rationalization project of the coal industry, Is abandoned.

Environmental pollution in these abandoned mines is a subject that is frequently being addressed. Environmental pollution problems from abandoned mines arise mainly from mine waste rock, tailing and acid mine drainage (AMD) associated with them.

AMD in the abandoned mine area refers to low-effluent water generated by the oxidation of sulfide and iron (Fe) in the wastewater and mine wastes. This is because pyrite (FeS ₂ ) and petroleum (FeS) Are formed by reacting with water and oxygen under aerobic conditions. It is known that hydrogen ions are generated during the reaction to produce AMD having a low pH value.

AMD in abandoned mines contains heavy metal ions such as aluminum, cations such as aluminum, iron, manganese, cadmium, arsenic, and high concentrations of sulphate, and because the pH is very low, these AMD contaminate the soil and groundwater in nearby areas Crops will be adversely affected. In addition, AMD flows into rivers and forms reddish brown deposits on the bottom of the stream, which has a negative impact on the ecological environment.

Today, AMD's processing methods can be roughly classified into two categories: first, preventing AMD formation; and second, inhibiting the activity of microorganisms.

The AMD formation prevention method is a method of preventing the formation of AMD by blocking the supply of oxygen to a specific region. This method is intended to prevent the oxidation of pyrite by oxygen by putting synthetic materials on the soil of abandoned mines or abandoned mines, or by blocking the supply of oxygen by blocking the mines of abandoned mines. However, such a method has a problem in that it is impossible to shut off a perfect oxygen supply, and thus the groundwater contamination area can be further diffused.

The method of inhibiting activity of the microorganisms is a method of inhibiting the oxidation of pyrite by sterilizing a microorganism (for example, Thiobacillus ferrooxidans) which determines the oxidation rate of pyrite. In order to sterilize the oxidizing microorganism of the pyrite, an additional microorganism sterilant should be administered. As such sterilant, sodium lauryl sulfate or sodium benzoate is mainly used. In West Virginia and Dawmont in the United States, this method was used to reduce the leakage of AMD. However, this method is not suitable for the acidification of mine drainage due to the fact that the sterilizing agent may cause further water pollution, maintain the continuous application of the sterilant, and the effective sterilant supply depends on the structural and hydraulic geology characteristics. There is a problem with the method of preventing.

On the other hand, since abandoned mines in Korea are mainly concentrated in mountainous areas, especially in Gangwon area, there is a problem that it is difficult to secure a site for a natural purification facility for AMD having a very high pollution load, And management of mine waste and the establishment and operation of facilities that can prevent pollution from mining areas are being neglected.

Although this problem is not limited to Gangwon area but it is a common phenomenon in the area where abandoned mines exist, there are very few researches and techniques to solve such problems.

Korean Patent No. 10-527336 "Method for Purifying and Purifying Acid Mine Drainage Using Sulfate Reducing Bacteria" (2005. 11. 2); Korean Patent No. 10-427774 "Method and apparatus for purifying abandoned mine drainage" (2004. 4. 7.); Korean Patent No. 10-667095 "Mine drainage treatment apparatus and mine drainage treatment method using same" (2007. 4. 4.); Korean Patent No. 10-649729 "Purification apparatus and purification method of acid wastewater" (Nov. 17, 2006); Korean Utility Model Registration No. 20-357173 "High Concentration Transfer Device for Acid Wastewater" (2004. 14. 14).

Disclosure of Invention Technical Problem [7] The present invention has been made to solve the above problems of the prior art, and it is an object of the present invention to physically neutralize acid mine drainage discharged from abandoned mines or mines by using a waste egg shell, It is an object of the present invention to provide a method for treating acid mine drainage which proceeds in a hybrid manner by biologically removing heavy metals present in the secondary neutralized mine drainage and simultaneously obtaining biomass .

In order to accomplish the above object, the present invention provides a method of treating a mine drainage wastewater, comprising: a pre-treatment step of collecting acidic mine wastewater discharged from abandoned mines or fugitive mines, removing suspended matters and contaminants from the mines; The dried egg shell powder is added to the pretreated mine wastewater at a rate of 20 g / L to 30 g / L and is kneaded for 20 to 60 minutes to neutralize the mine drainage and to adsorb some heavy metals in the mine drainage A neutralization treatment step of mine drainage; The selected microalgae are cultivated at a constant temperature and culture conditions and grown for 7 days to 12 days. The neutralized mine drainage and the culture of the microalgae are then mixed at a ratio of 10: 0.5-3 volume (v / v) and kneaded for 1 day to 6 days at room temperature while supplying air from the outside. In the course of the mixing, the micro-algae for drinking water feeds the nutrients in the mine drainage to the mine drainage A photobiological treatment step with microalgae removing heavy metal contaminants; A finishing treatment step of discharging the treated water through the biological treatment step with the microalgae and separately obtaining microalgae grown by absorbing heavy metal contaminants in the previous stage; .

The present invention primarily neutralizes acidic mine drainage using pulpy egg shell powder and partially removes heavy metals in mine drainage, thereby effectively removing the final heavy metal material.

In addition, since the present invention treats AMD by using pulpy egg shell powder and microalgae, it can utilize municipal waste, and is environmentally friendly and economical because it does not use chemicals as in the prior art.

Further, since the present invention can remove heavy metals in mineral wastewater and additionally obtain biomass due to microalgae, it can be used for other purposes such as biodiesel using biomass, and thus it is an allotment.

1 is a schematic block diagram of a method for treating mine drainage according to the present invention,
2 is a conceptual diagram of a treatment apparatus suitable for carrying out a method of treating mine drainage according to the present invention,
FIG. 3A is a pulpy egg shell powder used in the present invention,
FIG. 3B is an SEM photograph of the lung egg shell powder,
FIG. 4 is a graph showing the neutralization process of mine drainage by time zone,
FIG. 5 is a graph showing the removal rates of heavy metal contaminants after the entire process of the present invention,
Figure 6 is a chart showing the amount of biomass obtained after the entire process of the present invention,
FIG. 7 is a graph showing the comparison of heavy metal removal efficiencies of AMD with respect to each of the case of using the pulpy egg shell powder and the case of traveling in the hybrid system.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of describing the technical idea of the present invention in more detail and that the technical idea of the present invention is not limited thereto and that various modifications are possible. In the description of the present invention, the same reference numerals are used for the same parts, and parts that can be easily created by those having ordinary skill in the art are omitted in the description of the present invention .

In the present invention, the term "mine drainage" means drainage water or mine waste water flowing out from abandoned mines or mines. The mine drainage is usually acidic due to oxidation of sulfide and iron derived from waste wastes or mine waste and includes heavy metal ions such as aluminum, iron, manganese, cadmium and arsenic .

1 is a schematic block diagram of a method for treating mine drainage according to the present invention,

2 is a conceptual diagram of a treatment apparatus suitable for carrying out a method of treating mine drainage according to the present invention.

The present invention includes a pretreatment step (S 210) for removing suspended matters and contaminants from mine drainage.

The preprocessing step (S 210) collects the mine drainage generated in the mine or abandoned mine, and removes impurities such as float, soil, and fine dirt from them. The manner of removing the suspended matters and the contaminants in the mine drainage can be carried out by conventional methods and conventional means.

In the pre-treatment step (S 210), if the floating matters and the contaminants are removed in the mine drainage, it is preferable that the pre-treatment step (S 210) is put into a predetermined storage vessel and allowed to stand for a predetermined period. The waste water is supplied to the storage vessel to stabilize the pre-treated mine drainage, and to smoothly proceed to the next step. The storage vessel includes a commonly used flow rate regulator, and the screening operation may be performed thereafter or simultaneously.

The present invention includes a neutralization treatment step (S 220) of neutralizing the pre-treated mine drainage by a neutralizing adsorbent of the pulpy egg shell powder and removing a part of heavy metals in the mine drainage.

The present invention proceeds to the neutralization treatment step (S 210) of the mine drainage in two steps. First, in order to neutralize the pre-treated mine drainage, a neutralization adsorbent of the crushed egg shell powder is prepared, and then a neutralization adsorbent of the crushed egg shell powder is injected into the mine drainage to perform the neutralization process.

In order to neutralize mine wastewater, the present invention utilizes a waste egg shell that is discarded as food waste in daily life, and uses the waste egg shell as a neutralized adsorbent by appropriately processing the waste egg shell.

The lung egg shell collects egg shells (lung egg shells) that are discarded as food waste in daily life. Although the egg shell (lung egg shell) is classified as general food waste, it is not allowed to be discarded together with general food, and there is a limit to separate it. The present invention utilizes egg shells (lung egg shells) in this troublesome food waste, which is based on the fact that egg shells (lung egg shells) are composed mainly of calcium carbonate (CaCO ₃ ).

The pulmonary egg shell is prepared by removing the membrane portion composed of protein components, washing it cleanly, drying and finely pulverizing the pulmonary egg shell, or pulverizing the pulmonary egg shell to form pulmonary egg shell powder, It is preferably used as a neutralized adsorbent. When finely pulverized, the surface area can be further enlarged, which is advantageous in reacting with acidic drainage. More preferably, the waste egg shell is cleanly washed, dried at 90 to 120 ° C. for 7 to 12 hours, and finely pulverized to a size of approximately 300 to 600 mesh.

FIG. 3A shows the 325 mesh lung egg shell used in the embodiment of the present invention, and FIG. 3B shows the SEM photograph of the lung egg shell powder.

On the other hand, when the waste egg shell powder is used in the form of powder, it is disturbed in the mine drainage. Therefore, it is more preferable that the waste egg shell powder is mixed with a predetermined binder component and formed into a predetermined fixed shape. The predetermined fixed shape is not particularly limited, but a dongle dongle shape is preferable. As a method of immobilizing, the mixture is first mixed with a predetermined binder and immobilized in a predetermined form, and then the immobilized lung egg shell assembly is dried at 90 ° C to 120 ° C for 7 hours to 12 hours, , It is recommended to use this as a neutralization adsorbent of mine drainage.

In the present invention, the neutralizing adsorbent of the pulpy egg shell powder is introduced into the pretreatment mine drainage as described above, and the neutralizing adsorbent of the pulpy egg shell powder is added at a rate of 20 g to 30 g per 1 liter of the mine drainage, And the mine drainage is neutralized and at the same time, some heavy metals in the mine drainage are adsorbed. When the neutralization adsorbent of the lung egg shell powder is added to the mineral wastewater at 20 g / L or less, it takes a long time to neutralize the mine drainage and it is difficult to obtain an appropriate level of neutralization effect. On the other hand, , It is found that the increase of the synergistic effect due to the excessive introduction of the neutralizing adsorbent is not large.

When the neutralized adsorbent of the pulpy egg shell powder is added to the mineral wastewater and continuously kneaded, the ionic substances present in the mineral wastewater are partially adsorbed on the neutralized adsorbent of the pulmonary egg shell powder, Calcium carbonate (CaCO ₃ ), which is the main component of the mine drainage, combines with acidic ions in the mine drainage and tends to neutralize.

As a result, the main component of the pulpy egg shell powder is combined with acid ions in the mine drainage to neutralize the mine drainage, while the fine pore structure of the pulpy egg shell powder adsorbs harmful heavy metal components in the mine drainage .

The present invention includes a photo-biological treatment step (S 230) by selecting a micro-algae for microbial algae and removing microbial contaminants from the neutralized mine drainage using the microalgae.

The photobiological treatment step (S 230) by the microalgae comprises a first step of selecting microalgae for fermentation and culturing and propagating, and a step of adding a culture of the microalgae to the neutralized mine drainage, And then proceeds to the second step of removing heavy metal contaminants in the waste water.

In order to treat mine drainage, it is preferable to select micro-algae for the treatment of mine drainage, cultivate selected microalgae at a constant temperature and culture condition, grow for 7 days to 12 days, and then introduce the microalgae into the photobioreactor.

In the present invention, micro-algae are selected and used from various microalgae. Unlike microalgae for seawater, microalgae are able to survive well in a water containing no salt, To the micro-algae. Since the micro-algae are neutralized at the stage of strong acidity in the mine drainage, the photobioreaction can proceed much more easily. Examples of the micro-algae containing the above-mentioned microcavity include Chlorella vulgaris , Scenemus sp., Botryococcus braunii , Eudorina unicocca , Microcystis sp., Navicula sp., Nannochloris sp. And the like may be exemplarily shown, but the present invention is not limited thereto.

Preferably, the microcavity is cultured in a JM medium (Jaworski's Medium, Thompson et al., 1988) and cultured for 7 to 12 days at a constant temperature of 22 ° C ± 2 ° C. Specific components of the JM medium are introduced in the following examples. It is preferable that the culture and propagation conditions of the microorganism containing the above-mentioned buffer solution are maintained at a pH (7.2 ± 0.3) and the period of the day (8 hours) and the night (16 hours).

The above-mentioned microorganism of the present invention can be used as it is after completion of the above-mentioned culture and propagation, but it is more preferable to use the microalgae by refining them. To this end, the cultured microalgae of the dipping microalgae are separated by a centrifuge into a supernatant and a culture, and then the supernatant is discarded by about 50% to 70% of the initial culture, and the remaining concentrated, It is advisable to use the microalgae culture as a 'purified microalgae culture for the water.'

In the present invention, the neutralized mine drainage and the culture of the microalgae are mixed at a volume ratio of 10: 0.5 to 3 (v / v) and kneaded at room temperature for 1 to 6 days while supplying air from the outside. In this process, the micro-algae-bearing microalgae are used as a feed for the heavy metal component in the mine drainage, and the heavy metal contaminants in the mine drainage are naturally removed.

In the present invention, 0.5 liters to 3 liters of the above-mentioned culture medium for microcavities for drinking water is added to 10 liters of the mine drainage inside the processing vessel and mixed. When the culture medium for microbial algae containing 10 liters of the mine drainage is fed at a rate of 0.5 liters or less, a long biological treatment period is required, which lowers pollutant removal efficiency of mine drainage, However, when the culture of the microalgae containing the above-mentioned microalgae is fed at a rate of 3.0 liters or more, the biological treatment period can be shortened. However, since the microalgae are required to bear an excessive cost for culturing the microalgae, Can not do it.

The present invention is characterized in that the mineral wastewater and the culture medium for microbial algae are slowly mixed in the processing vessel at room temperature for about 1 to 6 days, It feeds the material as a nutrient and induces it to grow. Such photobioreaction seems to be sufficient for about one to four days at room temperature. Typically, the room temperature may range from about 15 ° C to 30 ° C in summer, and from about 10 ° C to 25 ° C in winter, although there may be slight differences between summer and winter. In general, longer periods of incubation are required at lower temperatures, and higher nutrient removal efficiencies can be achieved even at shorter periods of incubation at higher temperatures.

Preferably, the photobioreaction introduces air and light from the outside into the inside of the processing vessel into which the microbes are introduced. The air serves as a means for supplying CO ₂ gas, and the light is used as an energy source for the micro-algae for photosynthetic action. When the air is supplied to the inside of the container, CO ₂ gas in the air is dissolved in the mine drainage, and the micro-algae are used for CO ₂ gas and light energy to perform a photosynthetic action. In addition, when air is supplied from the outside, the air bubbles up inside the processing vessel to rise upward, and the mineral wastewater is kneaded naturally in the process. In this kneading process, the micro-algae are continuously brought into contact with various contaminants in the mine drainage.

It is preferable that the photobioreaction utilizes a light supply medium that uniformly supplies light from the outside. The light supply medium can uniformly supply light generated from the outside to the mine drainage inside the container, thereby contributing greatly to the micro-algae present in the mine drainage performing the photosynthesis action together with the CO ₂ gas It is because. As such a light supply medium, a light guide plate (OP: Optical Panel) can be exemplified. The light guide plate may utilize those conventionally used in photobioreaction. Preferably, the light is provided through a light source, illuminated for 8 hours during the day, and blocked for 16 hours at night. (See Fig. 2).

The micro-algae are further grown in the inside of the container by using various kinds of salts remaining in the mine drainage as a nutrient source. Accordingly, the micro-algae can be proliferated exponentially in the mine drainage, thereby establishing a basis for biomass utilization. This means that when the heavy metal contaminants in the mine drainage are grown as a prey and the heavy metal components in the mine drainage are removed, the effect of the net gain is obtained.

In addition, since the micro-algae are grown by feeding various nutrients present in large quantities in general wastewater or industrial wastewater, even when these nutrients are simultaneously contained in the mine drainage, they can be effectively used as a removal means . Representative examples of such nutrients include dissolved inorganic nitrogen (N), dissolved inorganic phosphorus (P), ammonia, nitrite, nitrate, organic nitrogen compound, inorganic phosphate, organic phosphate, silicate and the like.

In the present invention, a finishing treatment step (S 240) for removing microbial algae grown by absorbing heavy metal contaminants after the photobiological treatment step (S 230) by the microalgae and discharging the treated water from which heavy metal contaminants have been removed, .

The present invention collects the microalgae grown from the heavy metal pollutants as a food in the processing vessel through the photobiological treatment step (S 230) by the microalgae. The collection method of the microalgae is not particularly limited. Iron oxide or the like which is commonly used in the interior of the treatment vessel is injected so that the microalgae are precipitated to the bottom and then the microalgae can be obtained through an outlet provided at the lower end of the treatment vessel. The microalgae have an advantage that they can be utilized as biological resources of new biomass.

In the present invention, the micro-algae are collected and then the treated water remaining in the treatment vessel is discharged to the outside while the heavy metal contaminants and the micro-algae are removed.

Hereinafter, the present invention will be described as a more specific example.

<< Example 1: Neutralization of AMD by neutralizing adsorbent of pulpy egg shell powder >>

The experiment was conducted by collecting AMD from Y mine in Kangwon province. As a result of the measurement of the mine drainage of the Y mine in Kangwondo, a large amount of heavy metal components were detected and are shown in Table 1 below.

     Mine drainage (AMD) composition and measurement results of Y mine    The detected component        Measured value    pH     2.41 (2.28-2.50)    DO [mg / L]     4.35 (3.10-4.88)    Water Temp. [° C]     12.10 (10.80-14.7)    Eh [mV] (redox potential)     322.28 (305.1-351.40)    EC [uS / cm] (electrical conductivity)     2295.00 (2070-2570)    Cu     22.78 (20.11-26.78)    Fe     137.48 (140.83-225.80)    Zn     19.77 (17.39-23.57)    As     0.45 (0.16-0.67)    CD     0.27 (0.15-0.36)    Mn     10.35 (9.23-11.95)

(ISTEK, EC-40N), DO (ISTEK, pH-20N), water temperature and EC were measured using the EC / TDS / Salinity meter Was measured using a DO / O ₂ / air meter (ISTEK, DO-30N) and acidity using a pH meter (SevenGO pro, Mettler Toledo). Fe, Cu, Zn, Mn, As, and Cd in the mine drainage were analyzed using an inductively coupled plasma atomic emission spectrometer (Perkin-Elmer, Optima 3300XL). The concentration of heavy metal ion in the AMD was in the order of Fe>Cu>Zn>Mn>As> Cd, and the Fe content was the highest.

The AMD of the Y mine was dried at 105 ° C for 12 hours and then pulverized into 325 mesh pulverized egg shell powder adsorbent. In order to confirm the proper composition ratio, 0-150 g / L of pulpy egg shell powder adsorbent After mixing, the mixture was stirred at 150 rpm for 0 to 180 minutes and precipitated for 1 hour. The supernatant was then obtained and the pH change of the supernatant was observed. The initial acidity of AMD of the Y mine was 2.41 ± 0.11.

FIG. 4 is a graph showing the neutralization process of the mine drainage by time zone.

As a result of agitation of the egg shell powder with AMD, the pH was gradually increased at 2.41 ± 0.11 and 6.75 ± 0.26 after 30 minutes agitation, indicating that the pH of the AMD was neutralized. After 90 minutes of stirring, the pH was 7.75, especially after 120 minutes of stirring, the pH was 7.92 ± 0.31, but there was no change in pH thereafter. Therefore, when the agitation time is increased, the tendency of neutralization is remarkably increased, but it is judged that it is preferable to perform about 20 minutes to 60 minutes, and most preferably about 30 minutes.

The pH of AMD was varied from 20 g / L to 6.8 ± 0.17 at 30 g / L and 7.01 ± 0.22 at 30 g / L. Therefore, the difference of 20 g / L and 30 g / L . The pH increased to 7.83 up to 90 g / L depending on the amount of lung egg shell, but the pH did not increase any more than 100 g / L regardless of the amount of lung egg shell. Calcium carbonate (CaCO ₃ ), which is most abundant in the lung egg shell, has a general pH of 9.3 to 9.8. In this experiment, the maximum pH that can be shown by reacting the lung egg with AMD was 7.92 ~ 7.93. To neutralize the AMD using lung egg shell, the concentration of 20g / L ~ 30g / L Was found to be optimal.

<< Example 2: Absorption of heavy metals by AMD by pulmonary egg shell neutralizing adsorbent >>

The experimental conditions according to Example 1 were put into a 30 mg / L pulmonary egg shell and stirred for 30 minutes, and the total reaction contact time was 180 minutes. After that, the components of each heavy metal were measured to measure the adsorption performance of the pulpy egg shell powder. The results are shown in Table 2 below.

  Removal rate of heavy metal adsorption in Y mine drainage     Fe     Cu     Zn     Mn    CD Initial concentration
[mg / L]
137.48
22.78
19.77
10.35
0.27 End concentration
[mg / L]
54.99
8.88
7.31
5.80
0.10 Removal
[%]
60.00
61.02
63.02
43.96
62.96

The experimental results show that 60.00% of Fe, 61.02% of Cu, 63.02% of Zn, 43.96% of Mn and 62.96% of Cd were removed as shown in Table 2 above.

Fe, Cu, Zn and Cd showed more than 60% removal rate, but Mn had 44% removal rate and relatively lower removal rate than other heavy metals. CaCO ₃ is a hexagonal bonding structure, which is larger than other compounds. In such a structure, Substituted or structurally spaced and adsorbed. Therefore, the removal ability of heavy metals is considered to be very good.

<< Example 3: Cultivation and proliferation of microalgae >>

The present invention selected spherical chlorella ( Chlorella vulgaris ) having a size of 3 to 8 μm as microalgae . The Chlorella vulgaris was cultivated in JM medium (Jaworski's Medium, Thompson et al., 1988), which was purchased from Korean Marine Microalgae Bank (KMMCC, Kores). Culturing conditions were proliferated for 7 days in a thermostat (23 ° C ± 1 ° C) with a cycle of pH (7.2 ± 0.3), day (8h) and night (16h).

The constituents of the JM medium were 4.0 g Ca (NO ₃ ) ₂ .H ₂ O, 2.48 g KH ₂ PO ₄ , 10.0 g MgSO ₄ .H ₂ O, 3.18 g NaHCO ₃ , 0.45 g _{EDTAFeNa, 0.45 g EDTANa 2, 0.496} g H 3 BO 3, 0.278 g MnCl 2 and _{H 2 O, 0.20 g (NH} 4) 6 Mo 7 O 24 and _{H 2 O, 0.008 g cyanocobalamin,} 0.008 g thiamine HCl, 0.008 g biotin, was 16.0 g NaNO ₃ and Na ₂ HPO ₄ and g 2H 7.2 O _2.

&Lt; Example 4: Treatment with microalgae of neutralized mine drainage &gt; >

The microbial cultures cultured and propagated according to Example 3 were mixed with the neutralized mine wastewater according to Example 2 to conduct the photobioreaction. For the 37 L of the mine drainage in the Y mine in Gangneung City, 3.7 L of the cultured Chlorella vulgaris culture for 7 days was added and the volume ratio of mine drainage and microalgae was adjusted to 10: 1. The initial concentration of Chlorella vulgaris was 1.12 ± 0.6 g / L.

A treatment apparatus as shown in FIG. 2 was used to treat the waste water solution mixed with the mine drainage of the Y mine and the Chlorella vulgaris culture.

The capacity of the processing vessel was 45 L [450 mm (width) * 300 mm (length) * 330 mm (height)]. The initial microalgae concentration was 1.12 ± 0.6 g / L and the neutral pH (7.2 ± 0.3) was maintained. The treatment temperature was 25 ℃ ± 2 ℃ and the period of day (8 hours) and night Respectively. A light guide plate (OP) was placed inside the processing container, and light was uniformly supplied using an LEDs lamp. At that time, the wavelength of the light was 430 to 670 nm and proceeded for 6 days. Since the light distribution inside the processing vessel was measured at a depth of 305 mm at 94%, it was found that at least 90% of light was uniformly diffused into the inside of the processing vessel. In addition, the treatment vessel was charged with 0.5 L of air per minute, and the amount of CO ₂ contained in the air was 0.02 vvm.

The processing vessel is connected to a plurality of measurement sensors connected to a computer to measure concentrations of heavy metal pollutants in the mine drainage, and circulation of mine drainage is continuously conducted through a circulation pump.

<< Example 5: Removal Efficiency of Heavy Metal Contaminants in Mineral Drainage >>

During the experiment according to Example 4, the concentration of heavy metal contaminants in the mine drainage of the Y mine was measured through a plurality of measuring sensors connected to a computer, and the following heavy metal pollutant removal phenomenon was confirmed .

As a result of photobiological reaction using the Chlorella vulgaris , the removal rates of heavy metals were 97.31% for Fe, 99.76% for Cu, 99.6% for Zn, 99.41% for Mn, Cd was found to be about 99.6% .

FIG. 5 is a graph showing the removal rate of heavy metal contaminants as a result of photobiological reaction using Chlorella vulgaris after neutralizing the mine drainage.

The growth of plants requires 15 elements: inorganic nutrients (C, H, O, N, P, K, S, Ca, Mg, Fe, Mn, Cu, Zn, B and Mo) The removal rate of Fe, Cu, Zn, and Mn was about 8 to 10% higher than that of Cd in Example 5, because Fe, Cu, Zn, and Mn required a small amount It is presumed that the removal rate is higher than that of Cd because it is an element. Therefore, it can be seen that the trace elements (Co, Mo, Ca, Mg, Cu, Zn, Cr, Pb and Se) harmful to human body can be removed by using microalgae for removing heavy metals from mine drainage.

&Lt; Example 6: Amount of biomass obtained when treating mine drainage &gt; >

During the experiment according to Example 4, the growth of Chlorella vulgaris was examined at the same time every day. Biomass yield was 2.82 g / L at the initial concentration of 1.12 g / L on day 3, which was 2.52 times higher than the initial concentration. Chlorella vulgaris continued to increase production until day 3, but slowed down from day 4 and remained unchanged at day 5 and 6.

FIG. 6 is a graph showing the production amount of biomass obtained in the experiment according to the sixth embodiment.

Meanwhile, FIG. 7 is a graph showing the heavy metal removal efficiency of AMD using the lung egg shell powder neutralizing adsorbent and the heavy metal removal efficiency of AMD when the microorganism is hybridized.

As shown in FIG. 7, it can be seen that the heavy metal component of AMD can be adsorbed and removed at a very high rate by utilizing the waste egg shell that is thrown away into household food waste, and the photobiological reaction by microorganisms Can be removed almost completely by removing the heavy metal component of AMD.

While the present invention has been particularly shown and described with reference to the preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, The range is determined and limited by the range.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (5)

A pretreatment step (S 210) of collecting acidic mine drainage discharged from an abandoned mine or a mine site, removing floating matters and contaminants from the mine drainage, and allowing the mine drainage to stay for a predetermined time before moving to the next step;
Dried at 90 ° C to 120 ° C for 7 hours to 12 hours and finely pulverized to a size of 300 to 600 mesh to prepare a neutralized adsorbent of a hollow egg shell powder for mine drainage,
The neutralized adsorbent of the pulpy egg shell powder is added to the pretreated mineral wastewater at a rate of 20 g to 30 g per liter of mineral wastewater and kneaded for 20 to 60 minutes to neutralize the mineral wastewater, A neutralization treatment step (S 220) of mine drainage which adsorbs and removes a part of heavy metals in the drainage;
The selected microalgae are cultivated under normal temperature and culture conditions and grown for 7 days to 12 days, and then the neutralized mine drainage and the microalgae culture are cultivated in a ratio of 10: 0.5 to 3: (V / v) and kneaded for 1 day to 6 days at room temperature while supplying air from the outside. In the course of the mixing, the micro-algae for drinking water feeds the nutrients in the mine drainage, A step (S 230) of photobiological treatment by microalgae to remove heavy metal contaminants in the sample; To
Wherein the mineral wastewater treatment method is a hybrid wastewater treatment method.
delete delete The method according to claim 1,
The photobiological treatment step (S 230) may be carried out in a JM medium under a constant temperature condition of 22 ° C ± 2 ° C, at pH (7.2 ± 0.3), at a period of day (8h) After culturing and growing for 12 days, the neutralized mine drainage and the culture of the microcavity were mixed at a volume ratio (v / v) of 10: 0.5-3 volume (v / v) Wherein the micro-algae are mixed with the nutrients in the mine drainage to remove heavy metal contaminants in the mine drainage.
5. The method of claim 4,
A finishing treatment step of discharging the treated water through the photobiological treatment step (S 230) and separately absorbing the heavy metal contaminants in the previous step to obtain the grown microalgae; Further comprising the steps of: (a) extracting the mineral wastewater from the waste water;

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