A method for combined inhibition of Microcystis aeruginosa

Abstract

The present invention provides a method for combined inhibition of Microcystis aeruginosa. The specific steps are: the toxic and non-toxic Microcystis aeruginosa algae liquid is pumped through a copper mesh low-voltage electric field device using a peristaltic pump, and then different concentrations of lysine are added, the voltage is controlled to be 0.4-0.6V, and the lysine concentration is 5-10mg / L. After the combination of lysine and the copper mesh low-voltage electric field, the inhibition rate on the 7th day can be increased to 80% or more. Compared with traditional algae inhibition methods, the copper mesh low-voltage electrode releases a small amount of copper ions, which have a higher algae inhibition efficiency when combined with the allelopathic substance lysine. It is expected to be used in small fountain landscape water bodies, which can inhibit algae without affecting the ornamental value.

Description

Technical Field

[0001] The invention belongs to the field of water bloom control, and particularly relates to a method for combined inhibition of Microcystis aeruginosa. Background Art

[0002] In eutrophic water bodies, the large-scale explosive growth of microalgae can cause serious algal blooms. Microcystis aeruginosa is a typical algae in algal blooms. Excessive growth covers the surface of the water body, which can lead to a decrease in dissolved oxygen in the water, causing a large number of aquatic organisms to die. At the same time, the water body will emit a foul odor, affecting its ecological landscape. Some microcystis even release algae toxins, which can endanger human health through drinking water, recreational water, etc. Therefore, the control of algae blooms is still one of the main tasks of water pollution control.

[0003] At present, common algae inhibition methods mainly include physical salvage, ultraviolet irradiation, addition of chemical agents, planting of aquatic plants, etc., which often have problems such as high cost, easy to cause secondary pollution, and long treatment cycle.

[0004] Allelopathic substances released by plants have been widely concerned because of their low toxicity and easy degradation, but direct addition will reduce their treatment efficiency due to their easy degradation characteristics, thereby increasing the treatment cost. Low-voltage electric field-assisted in-situ copper ionization technology is a new type of algae inhibition technology, which uses low-voltage electric field to enhance the permeability of cell membranes, and then uses the released in-situ copper to achieve the inactivation of microalgae (Liu Peirui etc. Electric-field enhanced microalgaeinactivation using a flow-through copper ionization cell [J]. Journal of Hazardous Materials. 2020), but there is also the possibility of microalgae re-growth. Based on the problem that allelopathic substances are easily decomposed and microalgae re-grow after low-voltage electric field-assisted in-situ copper ionization treatment, the present invention cleverly combines these two treatment methods, opens the transmembrane channel of the cell membrane through a low-voltage electric field, and then uses in-situ copper ions and allelopathic substances to jointly inhibit the growth of microalgae, thereby achieving a higher algae inhibition effect, and has broad application prospects. Summary of the invention

[0005] The purpose of the present invention is to provide an efficient and safe combined treatment technology based on the problem of Microcystis aeruginosa bloom in the water environment. The combined technology can effectively inhibit the growth of Microcystis aeruginosa by using a smaller allelopathic substance concentration and a smaller electric field strength.

[0006] The purpose of the present invention can be achieved by the following scheme:

[0007] First, the copper mesh electrode is ultrasonically cleaned to remove impurities on its surface. The ultrasonic time is 20 to 30 minutes. The algae liquid is pumped through the copper mesh low-voltage electric field reaction device by a peristaltic pump. The flow rate is set to 10 mL / min and the voltage is controlled at 0.4 to 0.6 V. Then, 5 to 10 mg / L of the allelopathic substance lysine is added.

[0008] The Microcystis aeruginosa includes non-toxic Microcystis aeruginosa (FACHB-526) and toxic Microcystis aeruginosa (FACHB-905).

[0009] The copper mesh electrode is a common copper mesh available on the market with a mesh size of 60. The surface impurities are cleaned with methanol and acetone before use. The preferred copper mesh voltage is 0.5V.

[0010] The algae cell concentration is 1×10 6 ~1×10 7 / mL, lysine is commercially available analytically pure L-lysine, and the dosage of lysine is 5-10 mg / L.

[0011] Compared with the prior art, the present invention has the following advantages:

[0012] The present invention selects cheap and readily available copper mesh as the electrode material and environmentally friendly lysine as the allelopathic substance, and utilizes a small amount of in-situ copper ions (less than 80 μg / L) and lysine released by the low-voltage electric field of the copper mesh to effectively inhibit the growth of aeruginosa microcapsules, and the inhibition effect is better than the low-voltage electric field, lysine treatment alone, and the combined treatment effect of direct addition of copper ions and lysine, and has broad application prospects. The technology is applied to small fountain landscape water bodies, without the need for cumbersome procedures such as salvage, and a copper mesh electrode is installed at the front end of the fountain pipe, and lysine is added to the water body at the same time, which can effectively inhibit the growth of microalgae in the water body without affecting the ornamental value of the water body. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a graph showing the copper ion release from the effluent of non-toxic and toxic Microcystis aeruginosa after low-voltage electric field treatment of the copper mesh in Example 1.

[0014] Figure 2 This is a diagram showing the inhibitory effects of different doses of lysine and copper mesh low-voltage electric field on non-toxic Microcystis aeruginosa in Example 2.

[0015] Figure 3 This is a diagram showing the inhibitory effect of different doses of lysine and copper mesh low-voltage electric field on toxin-producing Microcystis aeruginosa in Example 2.

[0016] Figure 4 This is a diagram showing the inhibitory effects of different doses of lysine and copper ions on non-toxic Microcystis aeruginosa in Example 3.

[0017] Figure 5This is a diagram showing the inhibitory effects of different doses of lysine and copper ions on toxin-producing Microcystis aeruginosa in Example 3. DETAILED DESCRIPTION

[0018] The present invention provides the above-mentioned method for jointly treating non-toxic and toxic Microcystis aeruginosa, comprising the following steps:

[0019] (1) The copper mesh was cut into a size of about 1 cm × 1 cm and ultrasonically cleaned with methanol and acetone for 20 to 30 min respectively. Then, the Microcystis aeruginosa solution was pumped through the copper mesh electrode reaction device at a fixed flow rate of 10 mL / min by a peristaltic pump, and the voltage was set to 0.5 V.

[0020] Lysine was dissolved in ultrapure water to prepare a 1 g / L lysine stock solution, which was then added to the algae solution after electric field treatment to make the lysine concentrations 5 mg / L and 10 mg / L, respectively. The low-voltage electric field treatment group and the lysine treatment group were used as controls, and three parallel samples were set up for each group.

[0021] (2) 5 mL of the combined-treated algae solution was placed in a 10 mL centrifuge tube, acidified with 2% nitric acid, and then centrifuged to collect the supernatant. The copper ion concentration in the water was determined by atomic absorption spectrometry.

[0022] (3) Copper sulfate was dissolved in ultrapure water to prepare a 50 mg / L copper sulfate stock solution, and then an appropriate amount of stock solution was added to make the copper ion concentration close to the in situ copper concentration released by the low-voltage electric field. Then, an appropriate amount of lysine stock solution was added to make the lysine concentrations 5 mg / L and 10 mg / L, respectively. At the same time, a single copper ion treatment group and a single lysine treatment group were used as controls, and three parallel samples were set up for each group.

[0023] The present invention is described in detail below with reference to specific embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0024] Example 1

[0025] The copper mesh was ultrasonically cleaned with methanol and acetone for 20 minutes, and then rinsed with distilled water. The copper mesh electrode was then placed in an electrode holder with a conductive sheet. The two electrodes were separated by an insulating gasket to prevent short circuits. Vaseline was applied to each part of the electrode holder to ensure that the reactor was airtight. After the reactor was assembled, the algae solution was pumped through the reactor at a fixed flow rate of 10 mL / min using a peristaltic pump, and a 0.5 V DC voltage was applied between the two electrodes.

[0026] Use an electronic balance to weigh 0.1 g of lysine and dissolve it in 100 mL of ultrapure water to prepare a 1 g / L lysine stock solution. Then add the prepared lysine stock solution to the water sample treated with the electric field to make the lysine concentrations 5 mg / L and 10 mg / L, respectively. Record the OD of each treatment group every 24 hours. 680 , and calculated the algal cell density and growth inhibition rate.

[0027] Example 2

[0028] After the combined treatment, 5 mL of algae solution was taken into a 10 mL centrifuge tube, acidified with 2% nitric acid for 30 min, centrifuged at 8000 rpm for 10 min using a refrigerated centrifuge, and the supernatant was filtered through a 0.2 μm filter membrane and the total copper concentration in the water sample was determined using an atomic absorption spectrometer.

[0029] Example 3

[0030] Use an electronic balance to weigh 0.05g of copper sulfate in 1L of ultrapure water to prepare a 50mg / L copper sulfate mother solution. Add the prepared copper sulfate stock solution to the Microcystis aeruginosa water sample to control the copper ion concentration to 80μg / L. Then add an appropriate amount of lysine stock solution to control the lysine concentration to 5mg / L and 10mg / L. Record the OD of each treatment group every 24h. 680 , and calculated the algal cell density and growth inhibition rate.

[0031] The results are as follows Figure 1 As shown, in Implementation Case 2, for non-toxic and toxic Microcystis aeruginosa, the total copper concentrations in the effluent were 69.8 μg / L and 73.3 μg / L, respectively, which are far below the Class II water quality standard (1000 μg / L) of the surface water environmental quality standard.

[0032] The results are as follows Figure 2 As shown, after the low-voltage electric field was combined with different concentrations of lysine, the growth of non-toxic Microcystis aeruginosa was slow. The combined inhibition rate of 5 mg / L lysine and 0.5V electric field on the 7th day could reach 79.55%, while the inhibition rates of lysine and copper mesh low-voltage electric field alone were only 43.48% and 54.86%. Compared with the control group, the growth of non-toxic Microcystis aeruginosa in the combined treatment group was significantly inhibited.

[0033] The results are as follows Figure 3 As shown, after the low-voltage electric field was combined with different concentrations of lysine, the growth of toxic Microcystis aeruginosa was slow. The combined inhibition rate of 5 mg / L lysine and 0.5V electric field on the 7th day could reach 84.39%, while the inhibition rates of lysine and copper mesh low-voltage electric field alone were only 27.22% and 73.03%. Compared with the control group, the growth of toxic Microcystis aeruginosa in the combined treatment group was significantly inhibited.

[0034] like Figure 4 As shown in the data, the addition of 80 μg / L copper ions had basically no significant effect on the non-toxic Microcystis aeruginosa, and there was no obvious synergistic effect when combined with lysine. This shows that the low-voltage electric field increases the permeability of the cell membrane and promotes the absorption of lysine and copper ions. Lysine and the copper mesh low-voltage electric field have a good combined inhibitory effect.

[0035] like Figure 5 As shown in the figure, adding 80 μg / L copper ions has little inhibitory effect on the toxin-producing Microcystis aeruginosa, and has a smaller combined effect when combined with low-concentration lysine, and the combined effect can reach 45.80%, but the inhibitory effect is significantly lower than the combined inhibitory effect of lysine and copper mesh low-voltage electric field. This shows that lysine and copper mesh low-voltage electric field have a good combined inhibitory effect.

[0036] In summary, the allelopathic substance lysine combined with the copper mesh low-voltage electric field of the present invention has a strong inhibitory effect on both non-toxic Microcystis aeruginosa and toxic Microcystis aeruginosa, and has the advantages of good treatment effect, long action period, and environmental friendliness.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for combined inhibition of Microcystis aeruginosa, characterized in that: The following steps are involved: The water sample of Microcystis aeruginosa was pumped through a copper mesh low-voltage electric field reaction device by a peristaltic pump, and then the allelopathic substance lysine was added to the water sample; The low-voltage electric field reaction device is assembled from a copper mesh electrode, a conductive sheet and an electrode bracket. A DC voltage is applied to both ends of the copper mesh electrode, the voltage is controlled at 0.4-0.6V, and the flow rate of the peristaltic pump is controlled at 10mL / min. The total copper concentration in the treated water samples was 60-80 μg / L.

2. The method for combined inhibition of Microcystis aeruginosa according to claim 1, characterized in that: The lysine is commercially available analytically pure L-lysine, and the lysine concentration is controlled at 5-10 mg / L.

3. The method for combined inhibition of Microcystis aeruginosa according to claim 1, characterized in that The Microcystis aeruginosa includes toxic and non-toxic Microcystis aeruginosa, and the initial algae density is 1×10 6 ~1×10 7 Pieces / mL.

4. The method for combined inhibition of Microcystis aeruginosa according to claim 1, characterized in that The voltage is 0.5V.

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