A method and device for removing algae from carbonate salt lake brine

Abstract

The present invention relates to a method for removing algae from carbonate salt lake brine, the method comprising: S1) using a micro-electrolysis system to treat carbonate salt lake brine to enrich and remove algae; S2) sending the water treated in step S1) into a modified steel slag adsorption tower for treatment; wherein the micro-electrolysis system in step S1) comprises a modified titanium electrode plate, the modified titanium electrode plate is a titanium electrode plate with a surface modified by one or more selected from ruthenium, cobalt, and platinum, wherein the specific surface area of ​​the modified steel slag in step S2) is 5.27-5.58 cm 2 / kg. According to the method and device disclosed in the present invention, by first using a micro-electrolysis system and then an adsorption process, algae in the carbonate salt lake are effectively removed, impurities are removed for the subsequent lithium extraction process, and the purity of the subsequent products is ensured. It belongs to a green salt lake production process and has good social and environmental benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of salt lake treatment, and in particular relates to a method and a device for removing algae in carbonate salt lake brine. Background Art

[0002] The brine of carbonate salt lake is rich in Li, B, K and trace elements Br, Cs, Rb, etc. The salt sediment minerals of the lake include rock salt, potassium salt, mirabilite, potassium mirabilite, gypsum, borax, magnesite, dolomite, natural alkali, lithium dolomite, Zabuye stone, etc. The carbonate ion of carbonate salt lake is 11~48 g / L, and the lithium is 0.7~1.6 g / L.

[0003] In industrial production, because brine contains impurities such as algae, dense algae often clog the filter cloth during the purification and filtration process, causing the purified liquid flow rate to be substandard. When mechanical filtration is used, penetration occurs. During the purification and filtration process of the downstream nanofiltration membrane process, the pretreated brine contains a small amount of algae, causing problems such as low mechanical efficiency of downstream equipment and high replacement costs. Therefore, the brine purification and algae removal pretreatment needs to be improved urgently. Summary of the invention

[0004] The purpose of the present invention is to effectively remove algae from brine according to the water quality and quantity of carbonate salt lake brine, to ensure the subsequent comprehensive utilization of carbonate salt lakes, to develop a carbonate salt lake algae removal process and device, to take green technology as the main task, and to comprehensively develop and utilize various salt lake resources.

[0005] An object of the present disclosure is to provide a method for effectively removing algae from carbonate lake brine.

[0006] Another object of the present disclosure is to provide an apparatus for removing algae from carbonate salt lake brine.

[0007] According to one aspect of the present disclosure, there is provided a method for removing algae from carbonate salt lake brine, the method comprising:

[0008] S1) Using a micro-electrolysis system to treat carbonate lake brine to enrich and remove algae;

[0009] S2) sending the water treated in step S1) into a modified steel slag adsorption tower for treatment;

[0010] Wherein, the micro-electrolysis system described in step S1) comprises a modified titanium electrode plate, wherein the modified titanium electrode plate is a titanium electrode plate whose surface is modified by one or more selected from ruthenium, cobalt, and platinum.

[0011] The specific surface area of ​​the modified steel slag in step S2) is 5.27-5.58 cm 2 / kg.

[0012] According to another aspect of the present disclosure, a device for removing algae from carbonate salt lake brine is provided, the device comprising: an inlet pump, a micro-electrolysis system, a lift pump, a modified steel slag adsorption tower, and a drainage pump, wherein the micro-electrolysis system comprises a modified titanium electrode plate, the modified steel slag adsorption tower contains modified steel slag,

[0013] Wherein, the modified titanium electrode plate is a titanium electrode plate whose surface is modified by one or more selected from ruthenium, cobalt, and platinum.

[0014] The specific surface area of ​​the modified steel slag is 5.27-5.58 cm 2 / kg.

[0015] Beneficial Effects

[0016] According to the method and device disclosed in the present invention, by first using a micro-electrolysis system and then an adsorption process, algae in carbonate salt lakes are effectively removed, impurities are removed for the subsequent lithium extraction process, and the purity of subsequent products is ensured. It belongs to a green salt lake production process with good social and environmental benefits. In particular, experiments have found that under the same conditions, when oxygen evolution reaction occurs, the modified titanium electrode has a lower cell voltage and better energy-saving effect, and can effectively remove algae in salt lakes. Moreover, the modified steel slag adsorbent greatly improves the ability to adsorb various algae. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a flowchart of a method for removing algae from carbonate salt lake brine according to one embodiment of the present disclosure.

[0018] Figure 2 It is a schematic diagram of a device for removing algae from carbonate salt lake brine according to an embodiment of the present disclosure, wherein the device includes a water inlet pump 1, a micro-electrolysis system 2, a modified titanium electrode plate 3, a lifting pump 4, a modified steel slag adsorption tower 5, modified steel slag 6, and a drainage pump 7. DETAILED DESCRIPTION

[0019] Unless otherwise specified, all technical and scientific terms used herein have the common meanings understood by those skilled in the art for the present invention. In case of conflict, the definitions in this specification shall prevail.

[0020] The following detailed description is merely illustrative in nature and is not intended to limit the present invention and its use. In addition, this document is not limited by any theory described in the above prior art or invention summary or the following detailed description or examples.

[0021] like Figure 1As shown, according to one embodiment of the present disclosure, a method for removing algae from carbonate salt lake brine is provided, the method comprising:

[0022] S1) Using a micro-electrolysis system to treat carbonate lake brine to enrich and remove algae;

[0023] S2) sending the water treated in step S1) into a modified steel slag adsorption tower for treatment;

[0024] Wherein, the micro-electrolysis system described in step S1) comprises a modified titanium electrode plate, wherein the modified titanium electrode plate is a titanium electrode plate whose surface is modified by one or more selected from ruthenium, cobalt, and platinum.

[0025] The specific surface area of ​​the modified steel slag in step S2) is 5.27-5.58 cm 2 / kg.

[0026] By using the above-mentioned micro-electrolysis system for enrichment and then adsorption, a synergistic effect can be produced on algae removal, thereby enhancing the removal effect.

[0027] According to one embodiment of the present disclosure, the chlorophyll a content in the carbonate salt lake brine is 2.5-6.8 μg / L, and the algae content is 1.2-7.9*10 4 Pieces / L.

[0028] When the chlorophyll and algae contents in the carbonate salt lake brine exceed the above ranges, the processing capacity of the method will be exceeded, resulting in the inability to effectively control the quality of the treated water.

[0029] According to one embodiment of the present disclosure, in step S1), the current of the micro-electrolysis system is 6-12 mA / cm 2 The spacing between the modified titanium electrode plates is 15~25 cm, the length and width of the modified titanium electrode plates are 0.5*0.1 m, the thickness of the modified titanium electrode plates is 5 cm, 5~8 sets of electrode plates are required to treat 1 cubic meter of salt lake brine, and the residence time of salt lake brine in the micro-electrolysis system is 25~45 min.

[0030] Within the above specific process range, the quality of the treated water can be effectively controlled. After treatment, the chlorophyll a is 1.1~2.3 μg / L, and the algae content is 5.5~8.1*10 2 Pieces / L.

[0031] According to one embodiment of the present disclosure, the modified titanium electrode plate is prepared according to the following method:

[0032] (1) Etching: The titanium electrode plate is polished, soaked in alkali solution, washed with water, etched with acid, rinsed, and then dried;

[0033] (2) Preparing a coating liquid: Mix ethanol and tetraethyl orthosilicate in a volume ratio of 5:1 to 7:1, stir to form an ethanol-tetraethyl orthosilicate solution, add 2 to 7 g / L ruthenium trichloride, 0.1 to 0.3 g / L cobalt chloride hexahydrate, and 0.01 to 0.02 mL / L platinum tetrachloride, and stir to form a coating liquid;

[0034] (3) The coating liquid is evenly applied on the surface of the titanium electrode, heated to 100-110°C, kept at a constant temperature for 75-105 min, then heated to 325-345°C, kept at a constant temperature for 15-25 min, cooled, and the above coating-drying-sintering-cooling process is repeated 5-9 times, and the last time the temperature is kept constant for 75-85 min. After cooling, the modified titanium electrode plate is obtained.

[0035] The above method can effectively reduce the electrode interface resistance, increase the actual surface area of ​​the electrode, increase the number of active adsorption points and improve the electrocatalytic activity.

[0036] According to one embodiment of the present disclosure, the modified titanium electrode plate is prepared according to the following method:

[0037] (1) First, polish the titanium electrode plate, then soak the polished titanium electrode plate in a sodium hydroxide solution with a mass ratio of 11-16% at a temperature of 72-93°C for 20-50 min, then rinse it with tap water, and then place the pure titanium plate in an oxalic acid solution with a mass ratio of 11-14% at a temperature of 85-101°C for etching for 0.3-1.2 h. After taking out the titanium plate, rinse it with pure water with a conductivity of 5-15 μs / cm for 2-5 times, and then dry it at 105°C and cool it;

[0038] (2) Preparation of coating liquid: Analytical pure ethanol and analytical pure ethyl orthosilicate were mixed in a volume ratio of 5-7:1, and mechanically stirred for 5 min to form an ethanol-ethyl orthosilicate solution. 2-7 g of ruthenium trichloride, 0.1-0.3 g of cobalt chloride hexahydrate, and 0.01-0.02 mL of platinum tetrachloride were added per liter of ethanol-ethyl orthosilicate solution, and mechanically stirred for 20 min to form a coating liquid.

[0039] (3) The coating liquid is evenly applied on the surface of the titanium electrode, placed in a muffle furnace, heated to 105°C at a heating rate of 4-6°C / min, kept at a constant temperature for 75-105 min, then heated to 325-345°C at a heating rate of 4-6°C / min, kept at a constant temperature for 15-25 min, cooled, and the coating-drying-sintering-cooling process is repeated 5-9 times, and the last time the temperature is kept constant for 75-85 min. After cooling, the modified titanium electrode plate is finally prepared;

[0040] The modified titanium electrode plate prepared according to the above method was tested by steady cyclic voltammetry relative to Ag-AgCl electrode in 1 molar sulfuric acid solution. The modified titanium electrode plate has a lower cell voltage and better energy-saving effect, and can effectively remove algae in salt lakes.

[0041] According to one embodiment of the present disclosure, in step S2), modified steel slag is placed in the modified steel slag adsorption tower as an adsorbent, the residence time in the modified steel slag adsorption tower is 22-35 min, and the modified steel slag occupies 85-92% of the internal volume of the modified steel slag adsorption tower.

[0042] In the present disclosure, modified steel slag refers to steel slag after surface treatment after steelmaking. It is loose and porous, has a large specific surface area, has negative charges at active sites, has strong adsorption properties, and can effectively remove various algae.

[0043] According to one embodiment of the present disclosure, the modified steel slag in step S2) is prepared according to the following method:

[0044] (1) grinding steel slag having a composition of 40-60% CaO, 10-20% iron, 10-25% silicon dioxide, 2-10% aluminum oxide, 5-15% magnesium oxide, 1-10% manganese, and 1-15% carbon, washing it with dilute hydrochloric acid, washing it with water 1-2 times, and drying it;

[0045] (2) Mix the dried steel slag, kaolin and diatomaceous earth in a mass ratio of (5-20):(1-10):1, and mechanically stir to form a premix;

[0046] (3) Soaking the premix in a petroleum ether solution, taking it out and heating it to 300-400° C., then keeping the temperature constant for 15-30 minutes, and cooling it to obtain the modified steel slag.

[0047] The density of the modified steel slag prepared according to the above method is 4.05~4.23 g / cm 3 The adsorption specific surface area is 5.27~5.58 cm 2 / kg, greatly improving the ability to adsorb various algae.

[0048] According to one embodiment of the present disclosure, the modified steel slag in step S2) is prepared according to the following method:

[0049] (1) The mass percentage of steel slag: CaO is 45.1~53.5%, total iron is 10.1~17.2%, silicon dioxide is 12.9~21.6%, aluminum oxide is 3.1~5.9%, magnesium oxide is 6.5~11.2%, manganese is 1.2~9.7%, and carbon is 1.1~12.3%; after ball milling, the particle size is screened to 300~400 mesh, washed 1~2 times with dilute hydrochloric acid with a mass ratio of 0.3~1.2%, and then washed 1~2 times with industrial water with a TDS (total dissolved solids) of 123~245 mg / L, and dried;

[0050] (2) Mix the dried steel slag, kaolin and diatomaceous earth in a mass ratio of 8-15:2-5:1, and mechanically stir for 15-25 minutes to form a premix;

[0051] (3) Soaking the premix in a 1.1-2.3 mol / L petroleum ether solution for 2-4 h, taking it out and placing it in a muffle furnace, heating it to 310-375° C. at a heating rate of 2-5° C. / min, then keeping the temperature constant for 15-30 min, and cooling it to prepare the modified steel slag;

[0052] After being treated with the modified steel slag prepared according to the above method, the chlorophyll a in the salt lake brine was 0.05~0.1 μg / L, and the algae content was 10~35 / L.

[0053] According to another embodiment of the present disclosure, a device for removing algae from carbonate salt lake brine is provided, the device comprising a water inlet pump, a micro-electrolysis system, a lifting pump, a modified steel slag adsorption tower, and a drainage pump, wherein the micro-electrolysis system is equipped with a modified titanium electrode plate, the modified steel slag adsorption tower is equipped with modified steel slag,

[0054] The modified titanium electrode plate is surface-modified by one or more selected from ruthenium, cobalt, and platinum.

[0055] The specific surface area of ​​the modified steel slag is 5.27-5.58 cm 2 / kg.

[0056] Example

[0057] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the drawings and embodiments, but the content of the present invention is not limited to the following embodiments.

[0058] Example 1

[0059] Use as Figure 2The device for removing algae from carbonate salt lake brine shown in the figure is used to remove algae, the device includes a water inlet pump 1, a micro-electrolysis system 2, a lifting pump 4, a modified steel slag adsorption tower 5, and a drainage pump 7, wherein the micro-electrolysis system 2 includes a modified titanium electrode plate 3, and the modified steel slag adsorption tower 5 contains modified steel slag 6, and the modified titanium electrode plate 3 and the modified steel slag 6 are described below. The chlorophyll a of the input carbonate salt lake brine is 6.8 μg / L, and the algae content is 7.9*10 4 Pieces / L.

[0060] The salt lake brine enters the micro-electrolysis system through the water inlet pump, and a modified titanium electrode plate is placed in the micro-electrolysis system. The current of the micro-electrolysis system is 12 mA / cm 2 , the spacing between the modified titanium electrode plates is 25 cm, the length and width of the modified titanium electrode plates are 0.5*0.1 m, the thickness of the modified titanium electrode plates is 5 cm, and 8 sets of electrode plates are required to treat 1 cubic meter of salt lake brine. The residence time of salt lake brine in the micro-electrolysis system is 40 min. After treatment, the chlorophyll a is 2.0 μg / L, and the algae content is 6.2*10 2 Pieces / L.

[0061] The modified titanium electrode plate of the present invention is prepared as follows according to the characteristics of carbonate salt lake. (1) First, the titanium electrode plate is polished, and then the polished titanium electrode plate is immersed in a sodium hydroxide solution with a mass ratio of 15% at a temperature of 90°C for 45 minutes, and then rinsed with tap water. Subsequently, the pure titanium plate is placed in an oxalic acid solution with a mass ratio of 12% at a temperature of 98°C for etching for 1.1 hours. After the titanium plate is taken out, it is rinsed 5 times with pure water with a conductivity of 11 μs / cm, and then dried at 105°C and cooled. (2) Preparation of the brushing liquid: Analytical pure ethanol and analytical pure ethyl orthosilicate are mixed in a volume ratio of 7:1, and mechanically stirred for 5 minutes to form an ethanol-ethyl orthosilicate solution. 6 g of ruthenium trichloride, 0.3 g of cobalt chloride hexahydrate, and 0.02 mL of platinum tetrachloride are added to each liter of ethanol-ethyl orthosilicate solution, and mechanically stirred for 20 minutes to form a brushing liquid. (3) Apply the coating liquid evenly on the surface of the titanium electrode, put it into a muffle furnace, heat it to 105°C at a heating rate of 6°C / min, keep it at a constant temperature for 95 min, then heat it to 340°C at a heating rate of 6°C / min, keep it at a constant temperature for 25 min, and cool it. Repeat the above coating-drying-sintering-cooling process 7 times, and keep it at a constant temperature for 85 min for the last time. After cooling, a modified titanium electrode plate is finally prepared. Through modification, the electrode interface resistance is reduced, the actual surface area of ​​the electrode is increased, the number of active adsorption points is increased, and the electrocatalytic activity is improved.

[0062] The modified titanium electrode was tested by cyclic voltammetry in 1 molar sulfuric acid solution relative to the Ag-AgCl electrode. The results showed that the modified titanium electrode had a lower cell voltage and better energy-saving effect, and could effectively remove algae from salt lakes.

[0063] Then the salt lake brine enters the modified steel slag adsorption tower through a lifting pump, and the modified steel slag is placed in the modified steel slag adsorption tower as an adsorption medium. The residence time in the modified steel slag adsorption tower is 35 minutes. The modified steel slag accounts for 92% of the internal volume of the modified steel slag adsorption tower. The modified steel slag is loose and porous, has a large specific surface area, and the active sites are negatively charged. It has strong adsorption performance and can effectively remove various algae.

[0064] The modified steel slag is prepared and synthesized according to the characteristics of carbonate salt lake brine. The preparation process is as follows: (1) The mass percentage of steel slag is 49.2% CaO, 13.6% total iron, 15.5% silicon dioxide, 4.8% aluminum oxide, 8.2% magnesium oxide, 5.1% manganese, and 3.6% carbon. After ball milling, the particle size is screened to 400 mesh, washed twice with 2% dilute hydrochloric acid, and then washed twice with industrial water with a TDS of 245 mg / L, and dried. (2) The dried steel slag: kaolin: diatomaceous earth are mixed in a mass ratio of 15:4:1, and mechanically stirred for 25 minutes to form a premix. (3) The premix is ​​placed in a 1.9 mol / L petroleum ether solution and soaked for 4 hours. After taking it out, it is placed in a muffle furnace and heated to 310~375℃ at a heating rate of 5℃ / min, then kept at a constant temperature for 30 minutes, and then cooled to prepare modified steel slag. After the preparation process, the density of the modified steel slag is 4.11 g / cm 3 The adsorption specific surface area is 5.39 cm 2 / kg, greatly improving the ability to adsorb various algae.

[0065] After being treated in the modified steel slag adsorption tower, the chlorophyll a in the salt lake brine was 0.07 μg / L and the algae content was 23 / L.

[0066] After being processed by this process, the algae in the carbonate salt lake are effectively removed, impurities are removed for the subsequent lithium extraction process, and the purity of subsequent products is ensured.

[0067] Example 2

[0068] Use as Figure 2 The device shown is used to remove algae from carbonate salt lake brine, and the device includes an inlet pump 1, a micro-electrolysis system 2, a lifting pump 4, a modified steel slag adsorption tower 5, and a drainage pump 7, wherein the micro-electrolysis system 2 includes a modified titanium electrode plate 3, and the modified steel slag adsorption tower 5 contains modified steel slag 6, and the modified titanium electrode plate 3 and the modified steel slag 6 are described below.

[0069] The chlorophyll a content of the carbonate salt lake brine is 2.9 μg / L, and the algae content is 2.5*10 4 Pieces / L.

[0070] The salt lake brine enters the micro-electrolysis system through the water inlet pump, and a modified titanium electrode plate is placed in the micro-electrolysis system. The current of the micro-electrolysis system is 8 mA / cm 2 , the distance between the modified titanium electrode plates is 19 cm, the length and width of the modified titanium electrode plates are 0.5*0.1 m, the thickness of the modified titanium electrode plates is 5 cm, and 6 sets of electrode plates are required to treat 1 cubic meter of salt lake brine. The residence time of salt lake brine in the micro-electrolysis system is 30 min. After treatment, the chlorophyll a is 1.5 μg / L, and the algae content is 6.1*10 2 Pieces / L.

[0071] The modified titanium electrode plate of the present invention is prepared as follows according to the characteristics of carbonate salt lake. (1) First, the titanium electrode plate is polished, and then the polished titanium electrode plate is immersed in a sodium hydroxide solution with a mass ratio of 12% at a temperature of 83°C for 26 min, and then rinsed with tap water. Subsequently, the pure titanium plate is placed in an oxalic acid solution with a mass ratio of 11% at a temperature of 89°C for etching for 0.7h. After the titanium plate is taken out, it is rinsed 4 times with pure water with a conductivity of 7 μs / cm, and then dried at 105°C and cooled. (2) Preparation of the brushing liquid: Analytical pure ethanol and analytical pure ethyl orthosilicate are mixed in a volume ratio of 5:1, and mechanically stirred for 5 minutes to form an ethanol-ethyl orthosilicate solution. 4 g of ruthenium trichloride, 0.1 g of cobalt chloride hexahydrate, and 0.01 mL of platinum tetrachloride are added to each liter of ethanol-ethyl orthosilicate solution, and mechanically stirred for 20 minutes to form a brushing liquid. (3) The coating liquid was evenly applied on the surface of the titanium electrode, placed in a muffle furnace, heated to 105°C at a heating rate of 4°C / min, kept at a constant temperature for 80 min, then heated to 325°C at a heating rate of 4°C / min, kept at a constant temperature for 15 min, cooled, and the coating-drying-sintering-cooling process was repeated 6 times, and the last time was kept at a constant temperature for 75 min. After cooling, a modified titanium electrode plate was finally prepared. Through modification, the electrode interface resistance was reduced, the actual surface area of ​​the electrode was increased, the number of active adsorption points was increased, and the electrocatalytic activity was improved.

[0072] The modified titanium electrode was tested by cyclic voltammetry in 1 molar sulfuric acid solution relative to the Ag-AgCl electrode. The results showed that the modified titanium electrode had a lower cell voltage and better energy-saving effect, and could effectively remove algae from salt lakes.

[0073] Then the salt lake brine enters the modified steel slag adsorption tower through a lifting pump, and the modified steel slag is placed in the modified steel slag adsorption tower as an adsorption medium. The residence time in the modified steel slag adsorption tower is 25 minutes. The modified steel slag accounts for 87% of the internal volume of the modified steel slag adsorption tower. The modified steel slag is loose and porous, has a large specific surface area, and the active sites are negatively charged. It has strong adsorption performance and can effectively remove various algae.

[0074] The modified steel slag is prepared and synthesized according to the characteristics of carbonate salt lake brine. The preparation process is as follows: (1) The mass percentage of steel slag is 52.1% CaO, 16.2% total iron, 13.1% silicon dioxide, 3.3% aluminum oxide, 7.1% magnesium oxide, 2.7% manganese, and 5.5% carbon. After ball milling, the particle size is screened to 300 mesh, washed once with dilute hydrochloric acid with a mass ratio of 0.5%, and then washed once with industrial water with a TDS of 166 mg / L, and dried. (2) The dried steel slag: kaolin: diatomaceous earth are mixed in a mass ratio of 9:2:1, and mechanically stirred for 15 minutes to form a premix. (3) The premix is ​​placed in a 1.7 mol / L petroleum ether solution and soaked for 2 hours. After taking it out, it is placed in a muffle furnace and heated to 310°C at a heating rate of 3°C / min, then kept at a constant temperature for 15 minutes, and then cooled to prepare modified steel slag. After the preparation process, the density of the modified slag is 4.09 g / cm 3 The adsorption specific surface area is 5.31 cm 2 / kg, greatly improving the ability to adsorb various algae.

[0075] After being treated in the modified steel slag adsorption tower, the chlorophyll a in the salt lake brine was 0.06 μg / L and the algae content was 13 / L.

[0076] After being processed by this process, the algae in the carbonate salt lake are effectively removed, impurities are removed for the subsequent lithium extraction process, and the purity of subsequent products is ensured.

[0077] Comparative Example 1

[0078] The salt lake water was treated in the same manner as in Example 1 (ie, the first half of the experiment in Example 1), except that only electrolysis was performed without adsorption by modified steel slag.

[0079] As described in Example 1, after treatment, the chlorophyll a content was 2.0 μg / L and the algae content was 6.2*10 2 Pieces / L.

[0080] Comparative Example 2

[0081] The salt lake water was treated in the same manner as in Example 1, except that electrolysis was not performed and adsorption was performed directly by modified steel slag.

[0082] After treatment, the chlorophyll a content was 3.1 μg / L and the algae content was 8.5*10 2 Pieces / L.

[0083] Comparative Example 3

[0084] The salt lake water treated in Comparative Example 1 was electrolyzed twice using the same process.

[0085] After treatment, the chlorophyll a content was 1.2 μg / L and the algae content was 1.3*10 2 Pieces / L.

[0086] Comparative Example 4

[0087] The salt lake water treated in Comparative Example 2 was adsorbed twice using the same process.

[0088] After treatment, the chlorophyll a content was 0.9 μg / L and the algae content was 1.1*10 2 Pieces / L.

[0089] According to the results of the above comparative examples 1-4, it can be seen that the treatment effect of the present application cannot be achieved when only the electrolysis process or only the adsorption process is used. Surprisingly, after reducing the chlorophyll and algae content once, the treatment effect of the present application cannot be achieved when the same process is used repeatedly, which shows that by using the above micro-electrolysis system for enrichment and then adsorption, a synergistic effect can be produced on algae removal, and the removal effect can be enhanced.

[0090] Of course, those skilled in the art should realize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for removing algae from carbonate salt lake brine, the method comprising: S1) Using a micro-electrolysis system to treat carbonate lake brine to enrich and remove algae; S2) sending the water treated in step S1) into a modified steel slag adsorption tower for treatment; Wherein, the micro-electrolysis system described in step S1) comprises a modified titanium electrode plate, wherein the modified titanium electrode plate is a titanium electrode plate whose surface is modified by one or more selected from ruthenium, cobalt, and platinum. The specific surface area of ​​the modified steel slag in step S2) is 5.27-5.58 cm 2 / kg.

2. The method according to claim 1, wherein: The chlorophyll a content in the carbonate salt lake brine is 2.5~6.8 μg / L, and the algae content is 1.2~7.9*10 4 Pieces / L.

3. The method according to claim 1, wherein: In step S1), the current of the micro-electrolysis system is 6-12 mA / cm 2 The spacing between the modified titanium electrode plates is 15~25cm, the length and width of the modified titanium electrode plates are 0.5*0.1 m, the thickness of the modified titanium electrode plates is 5 cm, 5~8 sets of electrode plates are required to treat 1 cubic meter of salt lake brine, and the residence time of salt lake brine in the micro-electrolysis system is 25~45 min.

4. The method according to claim 1, wherein: The modified titanium electrode plate is prepared according to the following method: (1) Etching: The titanium electrode plate is polished, soaked in alkali solution, washed with water, etched with acid, rinsed, and then dried; (2) Preparing a coating liquid: Mix ethanol and tetraethyl orthosilicate in a volume ratio of 5:1 to 7:1, stir to form an ethanol-tetraethyl orthosilicate solution, add 2 to 7 g / L ruthenium trichloride, 0.1 to 0.3 g / L cobalt chloride hexahydrate, and 0.01 to 0.02 mL / L platinum tetrachloride, and stir to form a coating liquid; (3) The coating liquid is evenly applied on the surface of the titanium electrode, heated to 100-110°C, kept at a constant temperature for 75-105 min, then heated to 325-345°C, kept at a constant temperature for 15-25 min, cooled, and the above coating-drying-sintering-cooling process is repeated 5-9 times, and the last time the temperature is kept constant for 75-85 min. After cooling, the modified titanium electrode plate is obtained.

5. The method according to claim 1, wherein: The modified titanium electrode plate is prepared according to the following method: (1) First, polish the titanium electrode plate, then soak the polished titanium electrode plate in a sodium hydroxide solution with a mass ratio of 11-16% at a temperature of 72-93°C for 20-50 min, then rinse it with tap water, and then place the pure titanium plate in an oxalic acid solution with a mass ratio of 11-14% at a temperature of 85-101°C for etching for 0.3-1.2 h. After taking out the titanium plate, rinse it with pure water with a conductivity of 5-15 μs / cm for 2-5 times, and then dry it at 105°C and cool it; (2) Preparation of coating liquid: Analytical pure ethanol and analytical pure ethyl orthosilicate were mixed in a volume ratio of 5-7:1, and mechanically stirred for 5 min to form an ethanol-ethyl orthosilicate solution. 2-7 g of ruthenium trichloride, 0.1-0.3 g of cobalt chloride hexahydrate, and 0.01-0.02 mL of platinum tetrachloride were added per liter of ethanol-ethyl orthosilicate solution, and mechanically stirred for 20 min to form a coating liquid. (3) The coating liquid is evenly applied on the surface of the titanium electrode, placed in a muffle furnace, heated to 105°C at a heating rate of 4-6°C / min, kept at a constant temperature for 75-105 min, then heated to 325-345°C at a heating rate of 4-6°C / min, kept at a constant temperature for 15-25 min, cooled, and the coating-drying-sintering-cooling process is repeated 5-9 times, and the last time the temperature is kept constant for 75-85 min. After cooling, the modified titanium electrode plate is finally prepared.

6. The method according to claim 1, wherein: In step S2), modified steel slag is placed in the modified steel slag adsorption tower as an adsorbent, the residence time in the modified steel slag adsorption tower is 22-35 min, and the modified steel slag occupies 85-92% of the internal volume of the modified steel slag adsorption tower.

7. The method according to claim 1, wherein: The modified steel slag in step S2) is prepared according to the following method: (1) grinding steel slag having a composition of 40-60% CaO, 10-20% iron, 10-25% silicon dioxide, 2-10% aluminum oxide, 5-15% magnesium oxide, 1-10% manganese, and 1-15% carbon, washing it with dilute hydrochloric acid, washing it with water 1-2 times, and drying it; (2) Mix the dried steel slag, kaolin and diatomaceous earth in a mass ratio of (5-20):(1-10):1, and mechanically stir to form a premix; (3) The premix is ​​immersed in a petroleum ether solution, taken out and heated to 300-400° C., then kept at a constant temperature for 15-30 min, and cooled to obtain the modified steel slag.

8. The method according to claim 1, wherein: The modified steel slag in step S2) is prepared according to the following method: (1) The mass percentage of steel slag: CaO is 45.1~53.5%, total iron is 10.1~17.2%, silicon dioxide is 12.9~21.6%, aluminum oxide is 3.1~5.9%, magnesium oxide is 6.5~11.2%, manganese is 1.2~9.7%, and carbon is 1.1~12.3%; after ball milling, the particle size is screened to 300~400 mesh, washed 1~2 times with dilute hydrochloric acid with a mass ratio of 0.3~1.2%, and then washed 1~2 times with industrial water with a TDS (total dissolved solids) of 123~245 mg / L, and dried; (2) Mix the dried steel slag, kaolin and diatomaceous earth in a mass ratio of 8-15:2-5:1, and mechanically stir for 15-25 minutes to form a premix; (3) The premix is ​​immersed in a 1.1-2.3 mol / L petroleum ether solution for 2-4 h, taken out and placed in a muffle furnace, heated to 310-375° C. at a heating rate of 2-5° C. / min, then kept at a constant temperature for 15-30 min, and cooled to prepare the modified steel slag.

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