KR20180092545A - Removal of Nutrients and Heavy Metals from Swine Wastewater by Microalgae, Ankistrodesmus bibraianus - Google Patents

Abstract

Provided is a method for removing heavy metals and nutritive salts in wastewater from pig farms using microalgae. By using the microalgae Ankistrodesmus bibraianus according to the present invention, it is possible to efficiently remove contaminants such as nutritive salts and phosphorus or copper in livestock wastewater, thereby being useful as a technology capable of purifying livestock wastewater in an eco-friendly way.

Description

{Removal of Nutrients and Heavy Metals from Swine Wastewater by Microalgae, Ankistrodesmus bibraianus}

The present invention provides a method for removing nutrients and heavy metals in swine wastewater using microalgae.

Environmental pollution caused by livestock wastewater containing a large amount of high concentration, poorly decomposable water pollutants generated as the livestock industry becomes an enterprise becomes increasingly problematic.

The amount of livestock wastewater generated is only 1% of the total amount of waste water and wastewater, but it contains higher concentrations of organic substances and nutrients than other wastewater, causing water pollution such as lake eutrophication and green algae. In terms of pollutant load, it accounts for 26% of the total wastewater and is a major factor in the water pollution source. Livestock wastewater contains high concentrations of phosphorus and nitrogen as well as heavy metals such as copper and zinc, which are injected into feeds of livestock as additives. Soil and water pollution due to heavy metals in compost and livestock are highly probable in the present situation where domestic livestock manure management policy which recommends using compost and livestock using livestock wastewater is applied.

Recently, heavy metals in livestock wastewater have been continuously detected, and heavy metals are toxic substances that are highly degradable and accumulative due to their physical and chemical properties. Most of the treatment of livestock wastewater is carried out by recycling the wastewater. The biological treatment method is applied to the purification treatment after the physical and chemical treatment method is applied to the pretreatment and the post treatment is the activated sludge method. However, this method has poor technological and economical difficulties in operation of the self-purification treatment facility of medium-sized or less livestock farms because the processing efficiency is low compared to the high maintenance cost, such as poor sedimentation of sludge and frequent expansion of sludge. I do not. Therefore, there is a need for an environmentally friendly biological treatment method which is economical and easy to maintain and applicable to a small scale livestock farming self-purification facility, and has high treatment efficiency of nitrogen, phosphorus and heavy metals. In order to solve these limitations and problems, research on the purification of water using microalgae has recently been attracting attention.

Thus, the present inventors have found that the microorganisms belonging to the genus Oocystaceae and the green alga, Ankistrodesmus (Cu) and zinc (Zn), which are eutrophication limiting factors of bibraianus , were investigated , and it was confirmed that the efficacy of water purification is excellent when they are mixed with single or two species. The present invention has been completed.

Korea Registered Patent (0001) KR 10-1631591

The present invention relates to a water treatment purification method using micro-algae Ankistrodesmus bibraianus , and provides a method for effectively removing nutrients and heavy metals in livestock wastewater using environmentally-friendly biological resources.

In order to achieve the above object, the present invention relates to a microalgae for the treatment of livestock wastewater, which comprises Ankistrodesmus bibraianus (KCTC AG10324).

In one embodiment of the present invention, the anchidostomes vibranis may be grown at a temperature of 25 to 35 DEG C and a pH of 5 to 10.

The present invention also provides a method for removing nutrients and heavy metals in livestock wastewater using Ankistrodesmus bibraianus (KCTC AG10324).

In one embodiment of the invention the salts are selected from the group consisting of sodium chloride (NaCl), magnesium chloride (MgCl2), magnesium sulfate (MgSO4), calcium sulfate (CaSO4), potassium sulfate (K2SO4), calcium carbonate (CaCO3), magnesium bromide MgBr2), and combinations thereof.

In one embodiment of the present invention, the heavy metal may be copper (Cu) or zinc (Zn).

The present invention also provides a method for treating animal wastewater comprising the step of inoculating and culturing the anchid rosemus vibranias for livestock wastewater treatment according to claim 1 in a culture medium containing livestock wastewater.

The use of the microalgae Ankistrodesmus bibraianus of the present invention effectively removes pollutants such as phosphorus and copper in the livestock wastewater and thus is useful as a technology capable of purifying the livestock wastewater environmentally friendly Can be used to make.

1 is a photomicrograph of a microalgae used for the removal of nutrients and heavy metals in swine wastewater according to the present invention: (a) Chlorella vulgaris , (b) Scenedesmus obliquus , (c) Ankistrodesmus bibraianus, scale bar: 20μm.
FIG. 2 is a graph showing changes in temperature vulgaris (A) , Scenedesmus Obliquus (B) and Ankistrodesmus bibraianus (C).
Figure 3 is a graph showing the effect of pH on Chlorella vulgaris (A) , Scenedesmus Obliquus (B) and Ankistrodesmus bibraianus (C).
FIG. 4 is a graph showing the distribution of chlorella vulgaris (A) , Scenedesmus Obliquus (B) and Ankistrodesmus bibraianus (C).
5 is Chlorella vulgaris , Scenedesmus Obliquus and Ankistrodesmus bibraianus (the cultivation conditions were 28 ℃, pH 7 and 14:10 h light: dark cycle).

Hereinafter, the present invention will be described in detail.

The present invention is not a keystroke in algae belonging to the family of algae mousse Oocystaceae Death Viv rayiah Augustine (Ankistrodesmus bibraianus) (KCTC AG10324) by eutrophication limiting factors of nitrogen and phosphorus, and heavy metals which were to confirm the removal of the effect of copper (Cu) and zinc (Zn), temperature and pH, controlling the input concentration of Guangzhou group contaminants Ankistrodesmus bibraianus The present invention provides a method for efficiently removing nutrients and heavy metals in livestock wastewater by establishing optimal growth conditions.

The present invention provides a method for removing nutrients and heavy metals in livestock wastewater using Ankistrodesmus bibraianus (KCTC AG10324) of claim 1.

The " Ankistrodesmus " bibraianus " , Chlorophyceae River, Chlorococcales Neck, Oocystaceae It is a kind of green alga belonging to the genus. It is an algae that usually appears in lakes and reservoirs from spring to autumn. The cells are thin, long, needle-like, half-moon-shaped, and rumen-like. The color is green, and it forms a colony of four to sixteen cells, although it is a single species. Ankistrodesmus bibraianus cells are crescent-shaped, and cells are arranged in a cross shape. The length of the cell is 16-40 μm and the width is 2.5-8 μm. Generally, it grows in floating in the middle pumping station.

The term " microalgae " of the present invention means a single-celled organism capable of carrying out photosynthesis including a photosynthetic dye in a wide range, and refers to a microalga inhabited in aquatic environment, performing photosynthesis, Refers to a eukaryote that can grow as a single cell or form a single cell aggregate. It may be classified into freshwater algae living in fresh water and algae living in seawater depending on the environment in which they live. For the purpose of the present invention, the microalgae may be interpreted to mean birds belonging to the genus Chlorella, preferably Ankistrodesmus, which can normally multiply in animal wastewater containing high concentrations of salts, can be interpreted as microalgae of bibraianus , but are not particularly limited thereto.

The term " livestock wastewater " in the present invention means wastewater containing various wastes generated while raising livestock in a wide range, and narrow range includes wastewater mixed with water cleaning livestock manure and livestock wastewater discharge facility It is also called "livestock drainage (livestock drainage)" and includes not only various organic matter, nitrogen, phosphorus but also salts of high concentration. The BOD concentration is typically in the range of 28,500 to 65,000 ppm. Since the pollutant load is larger than the amount of wastewater generated, if it is discharged to public water bodies without proper treatment, the water quality and eutrophication of the lake will be deteriorated. It causes damage and causes serious environmental pollution. For the purpose of the present invention, the livestock wastewater is used as a subject to be treated or purified by a biological treatment method. In the present invention, the concentration of pollutants in livestock wastewater is the highest, But it is not particularly limited thereto.

The term " heavy metals " in the present invention refers to a metal element having a specific gravity of about 4 or more and includes antimony, lead, mercury, zinc, cadmium, chromium, arsenic and nickel. Among heavy metals, copper, zinc, nickel, cobalt, etc. are essential elements in living organisms, and they act as poisonous substances that are toxic to organisms when they are exposed to heavy metals at high concentrations. These heavy metals are easily adsorbed on the soil particles, causing heavy metal accumulation in the soil as well as secondary pollution such as water pollution and vegetation destruction. Unlike other organic contamination sources, heavy metals are not decomposed into toxic substances or converted into stable compounds, but remain in the ecosystem for a long time and pollute soil and water quality (Kumino et al., 2001). In recent years, heavy metals have been treated by ion exchange, activated carbon adsorption, and biological treatment (2002, Sastre et al., 2002).

The heavy metals detected in livestock wastewater are copper and zinc. Copper and zinc are essential nutrients for the growth of plants and animals, but they are known to cause toxicity when accumulated too much. Therefore, when the livestock wastewater containing a large amount of heavy metals is not purified and discharged into the river, or when it is used as a compost or livestock in the soil, it threatens the drinking water by polluting the river and the ground water and the farming harvested in heavy- Can cause indirect damage to animals and people who consume food

Copper (Cu) is a reddish and soluble metal. The risk of chronic poisoning is low due to the accumulation of sweat and urine in the urine when adults ingest 2 to 5 mg. However, excessive intake (lethal dose: 5 to 15 g) , It affects stomach upset, abdominal pain, liver, kidney trouble and so on. The average daily intake per person is 1.2 to 1.4 mg.

Zinc (Zn) is a bluish white metal. It is produced by ZnS, ZnO, ZnCO ₃ in nature and does not exist in natural water. However, zinc exists in the case of ground water because it is well soluble in water with a lot of carbon dioxide. Adult lethal dose is 3 to 5 g for ZnSO ₄ and 1 to 10 g for ZnCl ₂ and does not cause chronic poisoning but affects dermatitis, vomiting, diarrhea, loss of appetite, systemic toxicity and is mainly absorbed in the small intestine and duodenum And is excreted as feces.

The present invention also provides a method for treating animal wastewater comprising the step of inoculating and cultivating an anchidrosidemus vivrianus for the treatment of animal wastewater into a culture medium containing livestock wastewater.

The term " cultivation " of the present invention means a series of activities in which microorganisms are grown under moderately artificially controlled environmental conditions. In the present invention, the microalgae can be cultured using a method well known in the art. Specifically, the culturing can be carried out continuously in a batch process or in an injection batch or a repeated batch batch process (but not limited thereto).

The medium used for the culture should meet the requirements of the specific strain in a suitable manner while controlling the temperature, pH and the like under aerobic conditions in a conventional medium containing a suitable carbon source, nitrogen source, amino acid, vitamin, and the like. The carbon sources that can be used include glucose and xylose mixed sugar as main carbon sources, and sugar and carbohydrates such as sucrose, lactose, fructose, maltose, starch and cellulose, soybean oil, sunflower oil, castor oil, Oils and fats such as oils and the like, fatty acids such as palmitic acid, stearic acid and linoleic acid, alcohols such as glycerol and ethanol, and organic acids such as acetic acid. These materials may be used individually or as a mixture. Nitrogen sources that may be used include inorganic sources such as ammonia, ammonium sulfate, ammonium chloride, ammonium acetate, ammonium phosphate, ammonium carbonate, and ammonium nitrate; Amino acids such as glutamic acid, methionine and glutamine, and organic nitrogen sources such as peptone, NZ-amine, meat extract, yeast extract, malt extract, corn steep liquor, casein hydrolyzate, fish or their decomposition products, defatted soybean cake or decomposition products thereof . These nitrogen sources may be used alone or in combination. The medium may include potassium phosphate, potassium phosphate and the corresponding sodium-containing salts as a source. Potassium which may be used include potassium dihydrogen phosphate or dipotassium hydrogen phosphate or the corresponding sodium-containing salts. As the inorganic compound, sodium chloride, calcium chloride, iron chloride, magnesium sulfate, iron sulfate, manganese sulfate and calcium carbonate may be used. Finally, essential growth materials such as amino acids and vitamins can be used in addition to the above materials. In the present invention, BG-11 (BlueGreen) medium, which is widely used for microalgae growth, was used.

According to one embodiment of the present invention, the present inventors have found that, in order to treat livestock wastewater using microalgae, Ankistrodesmus bibraianus (KCTC AG10324) Chlorella vulgaris (KCTC AG10052) and Scenedesmus (TN and TP) and two nutrients (TN and TP) were mixed and treated with three microalgae (Fig. 5), and the optimum growth conditions of three microalgae of obliquus (KCTC AG20448) results confirmed the removal rate when Ankistrodesmus was bibraianus is confirmed that the greatest clearance (Table 4 and Table 5), a single heavy metals (Cu and Zn) and the two kinds of heavy metals (Cu and Zn) when hayeoteul blending Ankistrodesmus bibraianus that the removal rate is high (Table 6 to Table 8). Therefore Ankistrodesmus bibraianus Nutrients and heavy metals in livestock wastewater.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

< Example  1> Experimental material

<1-1> Microalgae Ankistrodesmus bibraianus )

Among the microalgae , Ankistrodesmus bibraianus (KCTC AG10324 ), a green alga belonging to Oocystaceae , was purchased from KCTC (Korea Research Institute of Bioscience and Biotechnology) (Fig. 1).

< Comparative Example > Microalgae Chlorella vulgaris , Scenedesmus obliquus )

Among the microalgae , Chlorella vulgaris (KCTC AG10052), Scenedesmus , a green alga belonging to Scenedesmus Obliquus (KCTC AG20448) was purchased from KCTC (Korea Research Institute of Bioscience and Biotechnology) (Fig. 1).

<1-2> Artificial wastewater

As artificial wastewater, BG-11 (BlueGreen) medium, which is widely used for microalgae growth, was used and the composition of the medium is shown in Table 1. The artificial wastewater was autoclaved at 121 ° C for 15 minutes to kill bacteria contained in the medium.

For a single TN processing included in BG-11 nitrogen source (NaNO ₃₎ to separate, remove using NaNO ₃ and NH ₄ Cl in the form of reagent at different concentrations of a single treatment of nitrogen (500, 1 000, 5 000, 10 000 mg / L).

For the single TN treatment, phosphorus (K ₂ HPO ₄ · 3H ₂ O) contained in BG-11 was removed and the K ₂ HPO ₄ form was observed to confirm the growth and removal rate of microalgae according to the concentration of nitrogen and phosphorus in the artificial medium (500, 1000, 5000, 10000 mg / L) using the reagent.

(NaNO ₃ ) and phosphorus (K ₂ HPO ₄ · 3H ₂ O) contained in BG-11 were removed as well as NaNO ₃ and NH ₄ Cl was used to adjust the total nitrogen concentration and the total phosphorus concentration was adjusted using K ₂ HPO 4 (500, 1 000, 5 000, 10 000 mg / L).

The single heavy metal treatment was performed after removal of EDTA contained in the composition of artificial wastewater because it causes heavy metal to be offset, and it was removed so as not to be affected by Cu and Zn contained in Trace metal A5. All of the heavy metal standard solutions and the reagents treated in the experiments were standard solutions made of Cu ^{2 +} and Zn ²⁺ available from KANTO CHEMICAL CO., Japan. The standard solutions prepared using reagents were treated so that Cu and Zn could be contained in the medium at concentrations of 10, 30 and 50 mg / L, respectively.

Heavy metals treated with 2 heavy metals were treated with the same reagents as the reagents used in the single heavy metals. The treatment concentrations of Cu were 10, 30 and 50 mg / L, and Zn (Zn) The concentrations of the compounds were 10, 30 and 50 mg / L, respectively.

BG-11 (BlueGreen) medium composition Component Amount in 1 L of distilled water NaNo ₃ 1.5 g K ₂ HPO ₄ 0.04 g MgSO _4. 7H ₂ O 0.075 g CaCl ₂ . 2H ₂ O 0.036 g Citric acid 0.006 g Ferric ammonium citrate 0.006 g EDTA 0.001 g Na ₂ CO ₃ 0.02 g Trace metal mix A5 1.0 mL Trace metal mix A5
(Amount in 1 L of distilled water)



MnCl ₂ .4H ₂ O 1.81 mL ZnSO ₄ .7H ₂ O 0.222 g Na ₂ MoO ₄ .2H ₂ O 0.39 g CuSO ₄ · 5H ₂ O 0.079 g Co (NO ₃ ) ₂ .6H ₂ O 0.049 g H ₃ BO ₃ 2.86 g

<1-3> Swine wastewater

The swine wastewater A used in the experiment was supplied from a large - scale livestock farm in Chungbuk, and B and C collected sterilized wastewater from a small - scale livestock farm facility in a sail. 3 Swine wastewater from farms (A, B, and C) was collected at a distance of 10 m from the water discharge from the housing facility. The samples were stored in a low temperature room at 4 ℃ for subsequent experiments. The components of the swine wastewater used in the experiment are shown in Table 2. The swine wastewater was removed by filtration after sedimentation.

Swine wastewater samples sampled from livestock farms Samples
pH
T-N T-P Cu Zn mg / L Wastewatera 5.8 6952 867 15.1 59.7 Wastewater B 6.3 5418 990 34.8 74.7 Wastewater C 5.6 6617 491 25.4 40.8

<1-4> Method of culturing microalgae

BG-11 (BlueGreen) medium (Table 1), which is conventionally used, was used as an artificial medium for subculture of microalgae. The amount of the medium in the microalgae reactor was 1 L, and 10% (v / v) pre-cultured microalgae were inoculated and subcultured at intervals of 2 weeks. The temperature was maintained at 28 ℃ and the culture medium was adjusted to pH 7. The photoperiod was tested under conditions of 14 hours of light source supply and 10 hours of light (dark cycle = 14: 10 h). The light source for cultivation was a daylight fluorescent lamp (FL20SGP) for plant cultivation and the light intensity was fixed at about 150 μmol / ㎡ / sec. Carbon dioxide was not supplied separately. But it was stirred by hand for three minutes for one minute. Because the period of microalgae takes 2 weeks to ingest and adapt nutrients in the artificial medium, the microalgae were cultivated for about 2 weeks and microalgae were collected and used during the experiment.

< Example  2> Analysis of microalgae growth according to environmental conditions

<2-1> Measurement of microalgae growth by temperature

In a 250-mL culture flask, 200 mL of BG-11 medium was added, and three pre-cultured microalgae were inoculated 0.5% (w / v) and cultured for 2 weeks. The light intensity was fixed at 150 μmol / ㎡ / sec and the temperature was changed at 15, 25, 28, 35 ℃.

<2-2> Measurement of microalgae growth by pH

In a 250-mL culture flask, add 200 mL of BG-11 medium and pre-culture Three microalgae were inoculated with 0.5% (w / v) and cultured for 2 weeks. Light intensity was fixed at 150 μmol / ㎡ / sec and cultured at pH 3, 5, 7, and 10, respectively.

<2-3> Measurement of microalgae growth by light period

In a 250-mL culture flask, 200 mL of BG-11 medium was added, and three pre-cultured microalgae were inoculated 0.5% (w / v) and cultured for 2 weeks. The light intensity was fixed at 150 μmol / ㎡ / sec and the light (dark) cycle was incubated at 10:14 h, 12:12 h, and 14:10 h.

<2-4> Measurement of microalgae growth

The amount of chlorophyll-a was measured to confirm the growth of three species of microalgae. Chlorophyll-a is a green pigment present in all birds, which accounts for 1-2% of the organic matter dry weight and is used as a potent indicator for evaluating the biomass of birds. The analysis was in accordance with ES 04312.1a for water pollution process test standard. 10 mL of the sample was filtered with a glass fiber filter paper (GF / C, 45 mm), and then the filter paper was put in a tissue grinder, and acetone and distilled water (9 + 1) were added thereto. The crushed samples were placed in a centrifuge tube, sealed, left in a dark place at 4 ° C for one day, and centrifuged (500 g, 20 minutes) to collect the supernatant and collect the volume. The separated supernatant was measured at wavelengths of 663 nm, 645 nm, 630 nm and 750 nm using a spectrophotometer (Model UV Mini 1240, Shimadzu, Kyoto, Japan) and the amount of chlorophyll-a was measured by the following equation.

[Mathematical Expression]

Chlorophyll-a (mg / m³) =

Y = 11.64 X 1 - 2.16 X 2 - 0.10 X 3

X 1 = O.D 663 O.D 750

X2 = O.D 645 O.D 750

X3 = O.D 630 O.D 750

O.D: Optical density

V ₁ = amount of supernatant (mL)

V ₂ = amount of filtered sample (L)

<2-5> Total nitrogen  (T-N) and total phosphorus (T-P) measurements

The total nitrogen (T-N) and total phosphorus (T-P) removal rates were analyzed to confirm changes in nitrogen and phosphorus in microalgae cultures. Total nitrogen and total phosphorus were analyzed according to the Water Pollution Process Test Standard Act.

Total nitrogen analysis was carried out by the oxidation method in the ultraviolet / visible spectroscopy. All nitrogen compounds in the samples were decomposed with organic matter at 120 ℃ using alkaline potassium persulfate, oxidized with nitric acid, and absorbance was measured at 220 nm in an acidic state. The calibration curve was set at 0, 0.5, 1, 1.5, and 2 mg / L. The standard curve of the calibration curves was prepared by adding 0, 2.5, 5, 7.5, and 10 mL of each standard solution to a 250 mL flask using a standard solution (20 mg / L) prepared in advance and distilled water to a total volume of 100 mL Respectively.

Total phosphorus analysis was performed by oxidizing and decomposing phosphorus in the form of an organic compound by ultraviolet / visible spectroscopy to convert all phosphorus compounds into phosphate (PO ₄ ^3- ) form and then reacting the ammonium molybdate produced by ammonium molybdate with ascorbic acid The absorbance of the molybdic acid produced by reduction was measured at 880 nm to quantitate the amount of total phosphorus. The calibration curves were set at 0, 0.25, 0.5, 0.75, and 1 mg / L, respectively. The standard curve of the calibration curve is prepared by adding 0, 5, 10, 15, and 20 mL to each 250 mL flask using a pre-prepared standard solution (5 mg / L) and gradually adding 100 mL of distilled water. Respectively.

<2-6> Analysis of heavy metals

Sampling for the analysis of heavy metals in artificial wastewater was done by collecting 10 mL every other day and filtering with a Whatman 0.45 um PP syringe filter. For the analysis of heavy metal removal rate in pig wastewater, it was analyzed by pretreatment method using nitric acid - sulfuric acid by water pollution process test standard method. Acid decomposition using nitric acid and sulfuric acid, and then analyzed with an inductively coupled plasma emission spectrometer (ICP-OES, Perkinelmer). The analytical conditions were set at analytical standards of standard reagents Cu ^{2 +} 1000 mg / L and Zn ^{2 +} 1000 mg / L, and high purity Ar (argon) was used as the carrier gas. The wavelength ranges of the heavy metals used are Cu ^{2 +} (327.393 nm) and Zn ²⁺ (206.200 nm), and the analysis conditions are shown in Table 3.

Analysis conditions of inductively coupled plasma luminescence photometer Item Analysis conditions RF power 1300 KW Nebulizer SeaSpray Plasma flow 15 L / min Auxiliary flow 0.2 L / min Nebulizer flow 0.65 L / min

< Example  3> Microalgae growth according to environmental conditions

<3-1> Growth Characteristics of Microalgae by Temperature

C hlorella The growth rate of vulgari s increased from 6 to 8 days after the lag phase was maintained until 6 days at all temperature treatments. The growth rate slowed down after 8 days. Showed the highest growth rate at 28 ℃, and the lowest growth rate at 15 ℃. Scenedesmus In the case of obliquus, the growth rate was slightly increased by temperature after the induction period was progressed from day 2 to day 2. The growth rate was explosively increased from the 6th day, and the stationary phase was started exactly from the 8th day at all temperature treatments. Scenedesmus obliquus also showed the lowest growth at 15 ℃ and the highest growth at 28 ℃. In the case of Ankistrodesmus bibraianus , the induction period was 6 days in all treatments and the growth rate started to increase after 6 days. Ankistrodesmus Unlike the other two species of microalgae, bibraianus grew until 10th day. At 15 ℃ and 35 ℃, the stationary phase started from the 10th day, but the growth continued at 12 ℃ at 25 ℃ and 28 ℃.

Therefore, all three species of microalgae were found to grow normally at 15, 25, 28, and 35 ℃, although the growth rate was different. The highest growth rate of all three species of microalgae was 28 ℃ and the growth rate was about 2-3 times higher than that of 15 ℃ (Fig. 2).

<3-2> Growth Characteristics of Microalgae by pH

Chlorella Vulgaris showed no growth under pH 3 and low growth under pH 10 basic condition. The growth rate of Chlorella vulgaris at pH 5 and 10 was slightly higher than that at pH 10, but showed similar growth rates without significant difference. It was confirmed that the growth was best at pH 7. Scenedesmus In the case of obliquus , Chlorella As in the case of vulgaris , growth was not achieved at pH 3. Similar growth rates were observed at pH 5 and 10. From 6th day, growth at pH 7 explosively increased. From 8th day, stationary phase was started in all treatments except pH 3. In the case of Ankistrodesmus bibraianus, as in the case of two kinds of microalgae, the induction period was 6 days, and the growth rate was increased from 6 days. Ankistrodesmus Bibraianus showed a slightly different growth rate than the other two kinds of microalgae but showed a high growth rate without any difference according to the conditions of pH 5, 7 and 10 except pH 3. Among them, the growth rate of Ankistrodesmus bibraianus at pH 7 was the highest. The stationary phase of Chlorella vulgaris and Scenedesmus obliquus started from 8th day, but the growth rate of Ankistrodesmus bibraianus was increased to 12 days in all treatments except pH 3.

All three microalgae showed the highest growth at pH 7, and the growth rate was about twice that of pH 3, which had the lowest growth rate (Fig. 3).

<3-3> Growth Characteristics of Microalgae by Light Period

As another factor affecting microalgae growth, photoperiod is also considered. Therefore, the light (dark cycle) condition was changed to 10:14 h (L: D cycle), 12:12 h (L: D cycle), and 14:10 h And the intensity of light was fixed at 150 μmol / m ² / sec.

Chlorella Vulgaris showed the lowest growth at 10:14 h (L: D cycle), and the induction period lasted until 8 days. Growth rates were increased at 12:12 h (L: D cycle) and 14:10 h (L: D cycle), and the difference between the two conditions was not significant. Growth progressed smoothly as photoperiod increased. Scenedesmus In the case of obliquus , the highest growth rate was observed at 14:10 h (L: D), and the growth was increased with increasing photoperiod. Ankistrodesmus In the case of bibraianus, the growth rate was similar at the early stage of the photoperiod of all conditions and the highest at 14:10 h (L: D). However, unlike the other two species of microalgae, the growth rate increased from day 6 to day 12 and continued until day 12.

All three microalgae showed the highest growth at L: D = 14: 10 h. Growth rate of L: D = 12:12 h and L: D = 14:10 h showed similar growth rates with almost no difference, but the growth rate was about 3 times higher than L: D = 10:14 h (Fig. 4).

Based on the above results, the optimal conditions for the microalgae were established. The microalgae culture conditions were maintained at 28 ℃, the medium was adjusted to pH 7, and the light (dark) cycle was 14: 10 h (FIG. 5).

< Example  4> Growth and nutrient removal rate of microalgae in artificial wastewater

<4-1> Single nutrient treatment (T-N and T-P) treatment

Treat.

Ankistrodesmus bibraianus Initial conc. After biotreatment RE (%) (mg / L)  (mg / L) single T-N treatment (mg / L) 500 500 ± 2.08 80 ± 0.87 84.0 1000 1000 ± 1.00 250 ± 1.53 75.0 5000 5051 ± 1.53 3853 ± 1.00 23.7 10000 10010 ± 2.08 7942 ± 0.49 20.7 single T-P treatment (mg / L) 500 500 ± 1.73 250 ± 1.00 50.0 1000 1000 ± 1.00 800 ± 2.08 20.0 5000 5000 ± 0.66 4100 + - 0.58 18 10000 10707 ± 0.19 8807 ± 0.77 17.7 Treat.

Chlorella vulgaris Initial conc. After biotreatment RE (%)
(mg / L) (mg / L) single T-N treatment (mg / L) 500 500 ± 2.08 100 ± 1.53 80.0 1000 1000 ± 1.00 290 ± 1.00 71.0 5000 5051 ± 1.53 3914 ± 3.21 22.5 10000 10010 ± 2.08 8059 ± 0.32 19.5 single T-P treatment (mg / L) 500 500 ± 1.73 250 ± 1.53 50.0 1000 1000 ± 1.00 771 ± 1.53 22.9 5000 5000 ± 0.66 4101 + - 0.46 18.0 10000 10707 ± 0.19 8826 ± 0.50 17.6 Treat.

Scenedesmus obliquus Initial conc. After biotreatment RE (%)
(mg / L) (mg / L) single T-N treatment (mg / L) 500 500 ± 2.08 150 ± 0.61 70.0 1000 1000 ± 1.00 400 ± 2.08 60.0 5000 5051 ± 1.53 4008 ± 1.00 20.6 10000 10010 ± 2.08 8245 ± 0.38 17.6 single T-P treatment (mg / L) 500 500 ± 1.73 330 ± 1.00 34.0 1000 1000 ± 1.00 907 ± 1.89 9.3 5000 5000 ± 0.66 4550 + - 1.01 9 10000 10707 ± 0.19 9806 ± 0.58 8.4

* RE means the removal efficiency.

The removal rates of microalgae treated with TN at concentrations of 500, 1000, 5000, and 10,000 mg / L, respectively, , 70%, 60%, 21% and 18% of Scenedesmus obliquus , and 84%, 75%, 24% and 21% of Ankistrodesmus bibraianus were found to be vulgaris , 71%, 23% It was confirmed that nitrogen removal ability was the best at a concentration of 500 mg / L. Among three microalgae , Ankistrodesmus It was confirmed that nitrogen concentration was decreased first immediately after the growth of bibraianus , and the highest removal rate was observed at all concentrations.

Therefore, the growth rate and removal rate of single nitrogen treatment in artificial wastewater were higher than those of Ankistrodesmus bibraianus > Chlorella vulgaris > Scenedesmus obliquus Respectively. The removal rate was higher in the lower concentration treatments, and no change in concentration was observed above the absolute amount removed at the higher concentration (Table 4).

<4-2> Mixed treatment of two kinds of nutrients (T-N and T-P)

Treat.
Ankistrodesmus bibraianus Initial conc.
(mg / L) After biotreatment
(mg / L) * RE (%) T-N (500 mg / L) + T-P (500 mg / L) T-N 500 ± 2.65 175 ± 1.36 65 T-P 501 ± 0.45 239 ± 0.25 52.3 T-N (1000 mg / L) + T-P (1000 mg / L) T-N 1005 ± 0.53 685 ± 1.00 31.8 T-P 1001 ± 1.02 810 + - 0.58 19.1 T-N (5000 mg / L) + T-P (5000 mg / L) T-N 5000 ± 1.53 3850 ± 1.53 23 T-P 5000 ± 3.06 4400 + - 2.61 12 T-N (10000 mg / L) + T-P (10000 mg / L) T-N 10000 ± 0.58 8200 ± 2.01 18 T-P 10000 + - 1.04 9200 ± 1.49 8 Treat.

Chlorella vulgaris Initial conc.
(mg / L) After biotreatment
(mg / L) * RE (%)
T-N (500 mg / L) + T-P (500 mg / L) T-N 500 ± 2.65 162 ± 2.08 67.6 T-P 501 ± 0.45 250 ± 0.18 50.1 T-N (1000 mg / L) + T-P (1000 mg / L) T-N 1005 ± 0.53 700 ± 2.08 30.3 T-P 1001 ± 1.02 856 ± 1.00 14.5 T-N (5000 mg / L) + T-P (5000 mg / L) T-N 5000 ± 1.53 4000 ± 1.85 20 T-P 5000 ± 3.06 4600 ± 1.00 8 T-N (10000 mg / L) + T-P (10000 mg / L) T-N 10000 ± 0.58 8500 ± 1.15 15 T-P 10000 + - 1.04 9600 ± 1.11 4 Treat.

Scenedesmus obliquus Initial conc.
(mg / L) After biotreatment
(mg / L) * RE (%)
T-N (500 mg / L) + T-P (500 mg / L) T-N 500 ± 2.65 210 ± 1.02 58 T-P 501 ± 0.45 299 ± 0.72 40.3 T-N (1000 mg / L) + T-P (1000 mg / L) T-N 1005 ± 0.53 790 + 1.53 21.4 T-P 1001 ± 1.02 884 ± 1.50 11.7 T-N (5000 mg / L) + T-P (5000 mg / L) T-N 5000 ± 1.53 4150 ± 2.08 17 T-P 5000 ± 3.06 4700 + - 0.74 6 T-N (10000 mg / L) + T-P (10000 mg / L) T-N 10000 ± 0.58 8800 ± 2.08 12 T-P 10000 + - 1.04 9700 ± 2.08 3

* RE means the removal efficiency.

The growth and removal rates of microalgae were compared between single and mixed treatment of TN and TP. The growth of each microalgae showed the highest growth at 500 mg / L and 1 000 mg / L when treated with nutrients. The growth of microalgae was slightly higher than that of single treatments, but no significant difference was observed. Also, as with single treatments, the growth of all three species of microalgae did not show a significant increase even after increasing concentrations of nutrients. However, it was confirmed that the time to reach the induction stage where the activity of microalgae increased sharply was delayed rather than the single treatment, and the removal rate for the mixed treatment of each microalgae was 500 mg / L, It looked. The microalgae growth and TN removal rates of the mixed treatment groups (500, 1000, 5000, 10,000 mg / L) were determined as Ankistrodesmus bibraianus (65%, 32%, 23%, 18%) > Chlorella vulgaris (68%, 30%, 20%, 15%) > Scenedesmus obliquus (58%, 21%, 17%, 12%). TP removal rate was higher in Ankistrodesmus bibraianus > Chlorella vulgaris > Scenedesmus obliquus (Table 5).

< Example  5> Analysis of microalgae growth and removal of heavy metals in artificial wastewater

<5-1> Treatment of single heavy metals (Cu and Zn)

Treat.

Ankistrodesmus bibraianus Initial conc. After biotreatment RE (%)
(mg / L) (mg / L) single Cu treatment (mg / L) 10 10 ± 1.05 1 ± 0.50 86.3 30 30 ± 0.20 20 ± 0.50 33.3 50 51 ± 0.58 39 ± 0.50 23.5 single Zn treatment (mg / L) 10 10 ± 1.50 6 ± 0.50 40.0 30 30 ± 1.34 25 ± 0.50 16.7 50 50 ± 1.35 43 ± 2.04 14.0 Treat.

Chlorella vulgaris Initial conc. After biotreatment RE (%)
(mg / L) (mg / L) single Cu treatment (mg / L) 10 10 ± 1.05 4 ± 0.08 62.7 30 30 ± 0.20 23 ± 0.63 23.3 50 51 ± 0.58 43 ± 0.70 15.7 single Zn treatment (mg / L) 10 10 ± 1.50 5 ± 0.49 50.0 30 30 ± 1.3 24 ± 0.17 20.0 50 50 ± 1.35 42 ± 0.92 16.0 Scenedesmus obliquus Treat.
Initial conc. After biotreatment RE (%)
(mg / L) (mg / L) single Cu treatment (mg / L) 10 10 ± 1.05 6 ± 0.12 40.3 30 30 ± 0.20 24 ± 0.20 20.0 50 51 ± 0.58 44 ± 0.15 13.7 single Zn treatment (mg / L) 10 10 ± 1.50 7 ± 0.19 30.0 30 30 ± 1.34 27 ± 0.30 10.0 50 50 ± 1.35 45 ± 0.95 10.0

* RE means the removal efficiency.

All of the microalgae showed inhibition of growth immediately after the injection into the treatment area, and the growth of microalgae was more rapidly inhibited as the concentration of treated heavy metals increased. The concentration of heavy metals in the treatments showed a tendency to decrease even during the period of inhibition of microalgae growth, but there was no change in concentration after the stop of microalgae growth. The removal efficiencies of microalgae in the Cu treatment (10, 30, and 50 mg / L) according to the overall growth and concentration of the microalgae were Anistrodesmus bibraianus (86% 33%, 24%) > Chlorella vulgaris (63%, 23%, 16%) > Scenedesmus obliquus (40%, 20%, 14%) (Table 6).

<5-2> Mixing of two heavy metals (Cu and Zn)

Treat.

Ankistrodesmus bibraianus Initial conc.
(mg / L) After biotreatment
(mg / L) RE (%)
Cu (10 mg / L) + Zn (10 mg / L) Cu 10 ± 0.58 2 ± 0.14 80.0 Zn 10 ± 0.40 6 ± 0.50 40.0 Cu (30 mg / L) + Zn (30 mg / L) Cu 30 ± 1.00 21 ± 0.40 30.0 Zn 30 ± 0.93 25 ± 1.15 30.0 Cu (50 mg / L) + Zn (50 mg / L) Cu 50 ± 0.58 38 ± 0.35 24.0 Zn 50 ± 0.07 45 ± 0.15 10.0 Treat.

Chlorella vulgaris Initial conc.
(mg / L) After biotreatment
(mg / L) RE (%)
Cu (10 mg / L) + Zn (10 mg / L) Cu 10 ± 0.58 2 ± 0.14 80.0 Zn 10 ± 0.40 3 ± 0.03 70.0 Cu (30 mg / L) + Zn (30 mg / L) Cu 30 ± 1.00 23 ± 0.15 23.3 Zn 30 ± 0.93 24 ± 0.25 20.0 Cu (50 mg / L) + Zn (50 mg / L) Cu 50 ± 0.58 41 ± 0.15 18.0 Zn 50 ± 0.07 42 ± 0.55 16.0 Treat.

Scenedesmus obliquus Initial conc.
(mg / L) After biotreatment
(mg / L) RE (%)
Cu (10 mg / L) + Zn (10 mg / L) Cu 10 ± 0.58 6 ± 0.34 40.0 Zn 10 ± 0.40 8 ± 0.27 20.0 Cu (30 mg / L) + Zn (30 mg / L) Cu 30 ± 1.00 23 ± 0.10 23.3 Zn 30 ± 0.93 26 ± 0.05 13.3 Cu (50 mg / L) + Zn (50 mg / L) Cu 50 ± 0.58 42 ± 0.15 16.0 Zn 50 ± 0.07 44 ± 0.35 12.0

* RE means the removal efficiency.

All three microalgae were more sensitive to Zn than Cu. The removal efficiencies of heavy metals in the microalgae of the mixed treated heavy metals Cu and Zn at 10 mg /Chlorella vulgarisend 80%, 23%, 18%Scenedesmus obliquusend 40%, 23%, 16%Ankistrodesmus bibraianusend 80%, 30% and 24% respectively. The removal rate of Cu isAnkistrodesmus bibraianusend The highest. In the case of Zn,Chlorella vulgaris70%, 20%, 16%Scenedesmus obliquusend 20%, 13%, 12%Ankistrodesmus bibraianusend 40%, 30%, 10%Chlorella vulgarisWas the highest. The most sensitive response to the toxicity of heavy metalsScenedesmus obliquus(Table 7).

< Example  6> Analysis of Nutrients and Heavy Metal Removal Rate in Swine Wastewater

Treat.

Ankistrodesmus bibraianus Initial conc.
(mg / L) After biotreatment
(mg / L) RE (%)
Waste water T-N 6952 ± 1.80 5353 ± 2.65 23.0 T-P 868 ± 1.05 763 ± 1.53 12.1 Cu 15 ± 0.26 6 ± 0.42 60.0 Zn 59 ± 0.68 51 ± 1.14 13.6 Waste water B T-N 5418 ± 1.06 4172 ± 1.53 23.0 T-P 991 + - 0.87 871 ± 0.58 12.1 Cu 35 ± 2.05 27 ± 0.58 22.9 Zn 75 ± 1.47 65 ± 0.68 13.3 Waste water C T-N 6617 ± 1.95 5096 + - 1.28 23.0 T-P 492 ± 3.53 432 ± 0.1 12.2 Cu 25 ± 1.50 18 ± 0.78 28.0 Zn 41 ± 1.45 33 ± 1.09 19.5 Treat.

Chlorella vulgaris Initial conc.
(mg / L) After biotreatment
(mg / L) RE (%)
Waste water T-N 6952 ± 1.80 5562 ± 1.53 20.0 T-P 868 ± 1.05 798 ± 2.52 8.1 Cu 15 ± 0.26 6 ± 0.58 60.0 Zn 59 ± 0.68 50 ± 0.80 15.3 Waste water B T-N 5418 ± 1.06 4334 ± 1.53 20.0 T-P 991 + - 0.87 911 ± 0.58 8.1 Cu 35 ± 2.05 27 ± 1.15 22.9 Zn 75 ± 1.47 65 ± 0.67 13.3 Waste water C T-N 6617 ± 1.95 5294 + - 0.97 20.0 T-P 492 ± 3.53 453 + - 0.81 7.9 Cu 25 ± 1.50 18 ± 0.65 28.0 Zn 41 ± 1.45 35 ± 0.76 14.6 Treat.
Scenedesmus obliquus Initial conc.
(mg / L) After biotreatment
(mg / L) RE (%) Waste water T-N 6952 ± 1.80 5570 + - 2.08 19.9 T-P 868 ± 1.05 815 ± 1.98 6.1 Cu 15 ± 0.26 8 ± 0.92 46.7 Zn 59 ± 0.68 52 ± 0.95 11.9 Waste water B T-N 5418 ± 1.06 4497 + 1.53 17.0 T-P 991 + - 0.87 931 + - 0.70 6.1 Cu 35 ± 2.05 28 ± 0.85 20.0 Zn 75 ± 1.47 69 ± 0.58 8.0 Waste water C T-N 6617 ± 1.95 5492 ± 0.94 17.0 T-P 492 ± 3.53 462 ± 1.04 6.1 Cu 25 ± 1.50 20 ± 0.67 20.0 Zn 41 ± 1.45 35 ± 0.50 14.6

* RE means the removal efficiency.

Experiments were conducted to investigate the feasibility and removal characteristics of pig wastewater based on the experimental results of growth and removal rates of three species of microalgae in artificial wastewater. The swine wastewater used in the experiments was supplied directly from three farm households in Chungbuk province. The pollutants in the swine wastewater were wastewater containing nutrients (T-N, T-P) and heavy metals (Cu, Zn). Three kinds of microalgae were treated with the same method as artificial wastewater for 14 days in this kind of swine wastewater.

The growth characteristics of the three microalgae in swine wastewater A, B and C were longer than that of the artificial wastewater treated with nutrients, and the growth of microalgae was inhibited after a certain period of time in artificial wastewater treated with heavy metals But the microalgae were continuously growing. Three kinds of microalgae in swine wastewater were treated and the removal rate was confirmed by measuring the initial concentration and final concentration of wastewater.

The growth characteristics of three kinds of microalgae in the swine wastewater of the A farmhouse were confirmed that the growth rate was increased from 8 days after the induction period was continued until 8th. The initial concentrations of pollutants in the farm wastewater were measured as TN 6952 mg / L, TP 868 mg / L, Cu 15 mg / L and Zn 59 mg / L, respectively. The removal rates of three microalgae against pollutants were 20%, 8%, 60% and 15% in Chlorella vulgaris , and Scenedesmus obliquus 20%, 6%, 47%, and 12%, respectively, while Ankistrodesmus bibraianus was identified as 23%, 12%, 60% and 14%.

In addition, the growth characteristics of three microalgae in pig farm wastewater of farm B were not significantly different from those of farming wastewater A, and the initial concentrations of TN 5418 mg / L and TP 991 mg / L , Cu 35 mg / L and Zn 75 mg / L. The removal rates of three microalgae against pollutants were 20%, 8%, 23% and 13% in Chlorella vulgaris , and Scenedesmus obliquus 17%, 6%, 20% and 8%, respectively, and Ankistrodesmus bibraianus was found to be 23%, 12%, 23% and 13%.

In addition, the growth characteristics of three microalgae in pig farm wastewater of farmhouse C were not significant, but the growth of microalgae in swine wastewater of farms A and B was not significant , The growth of three species of microalgae in the pig farm wastewater of the C farm was stopped on the 12th day. The initial concentrations of pollutants were measured as TN 6617 mg / L, TP 492 mg / L, Cu 25 mg / L and Zn 41 mg / L, respectively. The removal rates of three microalgae against pollutants were 20%, 8%, 28% and 15% in Chlorella vulgaris and Scenedesmus obliquus 17%, 6%, 20%, and 15%, respectively, while Ankistrodesmus bibraianus was identified as 23%, 12%, 28% and 20%.

The growth and removal rates of nutrients and heavy metals in three kinds of microalgae in swine wastewater were similar to those of artificial wastewater. As in the experiment using artificial wastewater, the lower the initial concentrations of nutrients and heavy metals in farm wastewater by farmers, the better the removal rate of three microalgae to swine wastewater.

Thus, Ankistrodesmus bibraianus showed the highest growth rate in the livestock wastewater, and the removal rate of nutrients and heavy metals showed the highest tendency. The growth and removal rates of Chlorella vulgaris were good, and Scenedesmus obliquus showed similar growth rates compared with the other two microalgae, but the lowest removal rates of nutrients and heavy metals were found (Table 8).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. Accordingly, the actual scope of the invention is defined by the appended claims and their equivalents.

Claims (6)

Micro-algae for the treatment of animal wastewater Ankistrodesmus bibraianus (KCTC AG10324). 3. The method according to claim 1, wherein the anchidostomus bibrianus (KCTC AG10324) is grown under the conditions of a temperature of 25 to 35 DEG C and a pH of 5 to 10, . A method for removing nutrients and heavy metals in livestock wastewater using Ankistrodesmus bibraianus (KCTC AG10324) of claim 1. The method according to claim 3, wherein the salts are selected from the group consisting of sodium chloride (NaCl), magnesium chloride (MgCl2), magnesium sulfate (MgSO4), calcium sulfate (CaSO4), potassium sulfate (K2SO4), calcium carbonate (CaCO3), magnesium bromide (MgBr2) And combinations thereof . The method for removing nutrients and heavy metals in livestock wastewater . The method of claim 3, wherein the heavy metal is copper (Cu) or zinc (Zn) . A method for treating livestock wastewater comprising the step of culturing anchovy rode desmus vibranias for livestock wastewater treatment according to claim 1 in a culture medium containing livestock wastewater.

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