Wastewater adsorbent and method of preparation and use thereof

Abstract

The present invention describes a wastewater adsorbent, a method for preparing it, and its use.The method comprises: mixing a carbon black powder and an ammonium salt solution, heating it for a hydrothermal reaction, followed by filtration, and washing the filter residues obtained with acid to obtain an ammonium salt modified carbon black; mixing and grinding a nickel-cobalt-manganese mixed salt and a sodium salt to obtain a mixture, mixing the mixture with an organic acid solution, evaporating the same to remove water, subjecting the same to a heating reaction in an inert atmosphere, and subjecting the reacted material to acid pickling to obtain a nickel-cobalt-manganese-sodium mixed salt; and mixing the nickel-cobalt-manganese-sodium mixed salt, the ammonium salt modified carbon black and a binding agent, and compacting, drying and heating the same to obtain a multi-metallic carbon-based adsorbent.The multi-metal carbon-based adsorbent prepared in the present invention has specific adsorption capabilities for sodium, ammonium radicals, and sulfate radicals; the carbon black powder serving as the carbon substrate material can adsorb multiple ions such as calcium, iron, manganese, and cobalt simultaneously, thus achieving diversified adsorption; furthermore, the adsorbent can be reused after desorption treatment and has a repeatable adsorption capacity.

Description

Wastewater adsorbent and method of preparation and use thereof FIELD OF INVENTION This description relates to the technical field of wastewater treatment, and specifically to a wastewater adsorbent and a method of preparing and using it. BACKGROUND OF THE INVENTION Currently, ternary positive electrode material is obtained through synthesis by sintering lithium salt and ternary precursor. The synthesis process of the ternary precursor includes the following two types: 1. The residual lithium-ion battery / electrode plate is disassembled and recycled to obtain battery powder, which is subjected to roasting, acid oxidation leaching, extraction, and purification to obtain a mixed nickel-cobalt-manganese salt, to which alkali and ammonia are added to obtain ternary precursor products; 2. Various minerals are subjected to acid leaching, precipitation and impurity removal, extraction, and purification to obtain nickel salt, cobalt salt, and manganese salt, respectively, which are used in combination with alkali and ammonia in synthesis to obtain ternary precursor products.Both of the aforementioned synthetic processes for the ternary precursors inevitably use acid, especially sulfuric acid, as a leaching agent; alkali as a precipitant and buffer; ammonia as a complexing agent; and an organic extractant to extract nickel, cobalt, and manganese metal ions. To prevent ammonium salts, sulfates, and organic extractants from remaining in the nickel-cobalt-manganese salt solution—which would result in a higher content of these salts in the ternary precursor exceeding the product's permissible standard—filtration and multiple pressure washings are often used to remove sodium ions. Therefore, more purified water is required to remove ammonium salts, sulfates, organic extractants, and other soluble impurities multiple times.Water consumption will increase, wastewater production will increase, and the cost of wastewater treatment will increase. On the other hand, with longer flushing times, the concentration of ammonium salts, sulfates, and organic extractants in the wastewater produced is decreasing, making treatment more difficult and preventing thorough removal of these salts, sulfates, and organic extractants. BRIEF DESCRIPTION OF THE INVENTION The present invention aims to solve at least one of the technical problems existing in the prior art mentioned above. For this reason, the present invention proposes a wastewater adsorbent and a method for its preparation and application. The first objective is to prepare a wastewater adsorbent, and the second objective is to provide a wastewater treatment method that uses the aforementioned wastewater treatment agent for the deep removal of ammonium salts, sulfates, and organic extractants. According to one aspect of the present invention, a method for preparing a wastewater adsorbent is proposed, comprising the following steps: S1: Mix carbon black powder with ammonium salt solution, heat for hydrothermal reaction and then filter, wash the resulting filter residue with acid to obtain ammonium salt modified carbon black; mix nickel-cobalt-manganese mixed salt and sodium salt to obtain a mixture, mix the mixture with an organic acid solution, evaporate to remove water and carry out the heating reaction in an inert atmosphere; wash with acid after the reaction to obtain nickel-cobalt-manganese-sodium mixed salt; S2: Mix the nickel-cobalt-manganese-sodium mixed salt, ammonium salt-modified carbon black, and a binding agent, compact, dry, and heat to obtain a multi-metal, carbon-based adsorbent. Heating in stage S2 is carried out under a nitrogen gas atmosphere; where, after compaction, a certain shape is obtained, such as a sheet shape, a block shape, a long rod shape, a spherical shape, and an irregular polygon shape. In some embodiments of the present invention, in step S1, the carbon black powder is obtained by acid oxidation leaching of battery powder recovered from a lithium battery. Furthermore, the average particle size of the carbon black powder is less than 0.1 mm. In some embodiments of the present invention, in step S1, the ammonium salt solution is one or more of ammonium sulfate, ammonium bisulfate, ammonium carbonate, ammonium bicarbonate, ammonium chloride, ammonium phosphate, or ammonium dihydrogen phosphate; preferably, the ammonium salt solution is one or two of ammonium sulfate or ammonium bisulfate solutions. In some embodiments of the present invention, the solid-liquid ratio of carbon black powder to ammonium salt solution is 10-500 g / L and, furthermore, the solid-liquid ratio of carbon black powder to ammonium salt solution is 50-200 g / L. In some embodiments of the present invention, the mass concentration of the ammonium salt solution is 0, 1-30%; furthermore, the mass concentration of the ammonium salt solution is 1-10%. In some embodiments of the present invention, in step S1, the temperature of the hydrothermal reaction is 100-400 °C; preferably, the time of the hydrothermal reaction is 1-10 h. In some embodiments of the present invention, in step S1, the sodium salt is one or more of sodium acetate, sodium hydroxide, sodium sulfate, sodium phosphate, sodium chloride, sodium nitrate, sodium oxalate, sodium citrate, sodium manganate, or sodium carbonate. In some embodiments of the present invention, in step S1, the average particle size of the mixture is less than 100 m. In some embodiments of the present invention, in step S1, the acid is one or more of sulfuric acid, nitric acid, phosphoric acid, or hydrochloric acid; furthermore, the concentration of the acid is 0.1-5 mol / L. In some embodiments of the present invention, in step S1, the nickel-cobalt-manganese mixed salt is prepared by battery recycling; preferably, the mass ratio of the sodium salt and the nickel-cobalt-manganese mixed salt is (1-10) : (0, 1-30). In some embodiments of the present invention, in step S1, the organic acid solution is one or more of oxalic acid, citric acid, acetic acid, formic acid, or acetic acid solution; the solid-liquid ratio of the mixture and the organic acid solution is 10: (50-200) g / mL, and furthermore, the mass concentration of the organic acid solution is 1-40%. In some embodiments of the present invention, in step S1, the temperature of the hydrothermal reaction is 300-1100 °C; preferably, the time of the hydrothermal reaction is 2-24 h. In some embodiments of the present invention, in step S2, the binding agent is one or more of calcium silicate, calcium alginate, clay silicate or sodium aluminosilicate; preferably, the mass ratio of the mixed nickel-cobalt-manganese-sodium salt, the ammonium salt modified carbon black and the binder is (10-50) : (30-70) : (0.1-8). In some embodiments of the present invention, in step S2, the heating temperature is 300-800 °C and, furthermore, the heating time is 2-24 h. In some embodiments of the present invention, in stage S2, the density after compaction is greater than 1.8 g / cm3. The present invention also provides a wastewater adsorbent, which is prepared by the preparation method. The present invention also provides for the use of the wastewater adsorbent in the treatment of ternary precursor wastewater. In some embodiments of the present invention, the method for treating ternary precursor wastewater comprises: settling, filtering, and strongly oxidizing the ternary precursor wastewater to obtain primary treated wastewater; adding the wastewater adsorbent to the primary treated wastewater for adsorption treatment; soaking the wastewater adsorbent in an acid for desorption; after adsorption-desorption treatments for 2-6 times, sending the treated wastewater to secondary treatment; and reusing the wastewater adsorbent for adsorption treatment again. It should be noted that the ternary precursor wastewater is the wastewater produced by acid leaching, precipitation and impurity removal, extraction and separation, alkali addition, ammonia addition, and aging in the ternary precursor production process. In some embodiments of the present invention, the solid-liquid ratio of the wastewater adsorbent with respect to the primary treated wastewater is (0.5-20) : (30-200) kg / L. In some embodiments of the present invention, the acid used for soaking and desorption is one or more of sulfuric acid, nitric acid, phosphoric acid, or hydrochloric acid, and its concentration is 0.01-3 mol / L. According to a preferred embodiment of the present invention, it has at least the following beneficial effects: 1. The wastewater adsorbent of the present invention has high stability and diverse adsorption options. After the carbon black powder in the wastewater adsorbent is modified by the hydrothermal ammonium salt, the polarity and acid-base properties of the carbon black powder change significantly, and the ammonium radical adsorption performance is improved.In the nickel-cobalt-manganese mixed salt, the manganese salt is the main component of the polymetallic adsorbent salt. Adding cobalt / nickel salts strengthens the adsorbent's stability. Using carbon black powder as the adsorbent's base material and heating it to synthesize the polymetal-carbon-based adsorbent further enhances the excellent inherent properties of the porous carbon in the carbon black powder, improves its surface properties, enhances the interaction between the adsorbent and the ions, and improves adsorption performance. The multi-metal-carbon-based adsorbent prepared in the present invention has a specific adsorption capacity for sodium, ammonium, and sulfate. As a base carbon material, the carbon black powder can simultaneously adsorb calcium, iron, manganese, cobalt, and many other ions. It exhibits diversified adsorption capabilities.Furthermore, the adsorbent can be reused after desorption treatment and has the capacity for repeated adsorption. 2. Using the method of the present invention, the production cost is significantly reduced. On the one hand, the raw material source for the polymetal carbon-based adsorbent synthesized by the invention can be the product recovered from waste batteries, where the carbon black powder can come from the negative electrode material of the waste battery, and the nickel-cobalt-manganese-sodium mixed salt can come from the positive electrode material of the waste battery. Therefore, the main materials of the adsorbent are secondary utilizations of waste material. On the other hand, the adsorbent synthesized by the present invention can be reused. After adsorbing the wastewater from the primary treatment, the adsorbent can be placed in an acid for desorption treatment and reused. Therefore, the recyclability of the material in the present invention is high. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further described below together with the accompanying drawings and examples, in which: Figure 1 is a process flow diagram of Example 1 of the present invention. Figure 2 is an SEM image of the wastewater adsorbent prepared in Example 2 of the present invention. DETAILED DESCRIPTION OF THE INVENTION Hereafter, the concept of the present invention and the technical effects produced will be described clearly and completely in conjunction with examples, to fully understand the purpose, features, and effects of the present invention. Obviously, the examples described are only a portion of the examples of the present invention, rather than all of them. Based on the examples of the present invention, other examples obtained by those skilled in the art without creative work fall within the scope of protection of the present invention. Example 1 A method for preparing the wastewater adsorbent and the wastewater treatment method were provided, with reference to Figure 1; the specific process was: (1) Modification of carbon black residue: Battery powder recovered from lithium batteries was oxidized by acid leaching to obtain carbon black residue. The carbon black residue was washed, dried, and ground to an average particle size of less than 0.1 mm to obtain carbon black residue powder. 34 g of carbon black residue powder were mixed with 200 mL of 3.3% ammonium sulfate solution and stirred to obtain an aqueous carbon black residue solution. The aqueous carbon black residue solution was placed in a sealed container for heating and hydrothermally reacted at 160 °C for 3 h 3 min; after cooling and filtration, the filter residue was washed with dilute acid and dried to obtain ammonium sulfate-modified carbon black residue. (2) Preparation of nickel-cobalt-manganese-sodium mixed salt: The nickel-cobalt-manganese mixed salt prepared by battery recovery was mixed with sodium sulfate and ground to an average particle size of less than 100 µm to obtain a mixture. The mixture was uniformly mixed with a 6.12 wt% oxalic acid solution, subjected to solid-liquid separation and evaporated to remove water, heated to 430 °C in an inert atmosphere, held at a constant temperature for 3 h 44 min, and cooled. 0.34 mol / L hydrochloric acid was added for acid pickling, and the mixture was washed and dried to obtain a nickel-cobalt-manganese-sodium mixed salt; where the mass ratio of sodium sulfate and the nickel-cobalt-manganese mixed salt = 3:12, and the solid-liquid ratio of the mixture to the oxalic acid solution is 10:50 g / mL. (3) Synthesis of polymetal-carbon based adsorbent: 15.8 g of nickel-cobalt-manganese-sodium mixed salt, 34 g of ammonium sulfate-modified carbon black residue, and 5 g of silicate clay were mixed and compacted to obtain a certain flake shape with a compaction density of 2.53 g / cm3, which was dried, heated to 485 °C in a nitrogen atmosphere, held at a constant temperature for 2 h and 12 min, and cooled to obtain a polymetal carbon based adsorbent. (4) Wastewater treatment by adsorbent adsorption: The wastewater produced by the preparation of the ternary precursor was settled, filtered, and heavily oxidized to obtain the primary treated wastewater, and the multi-metal and carbon-based adsorbent was added for adsorption treatment. After treatment, the adsorbent was soaked in 0.34 mol / L hydrochloric acid for desorption. After 5 adsorption-desorption treatments, the treated wastewater was sent to secondary treatment, and the adsorbent was reused for adsorption treatment again; where the solid-liquid ratio of adsorbent to wastewater was 1:13 g / mL. Example 2 A method for preparing the wastewater adsorbent and the wastewater treatment method were provided, and the specific process was: (1) Modification of carbon black residue: Battery powder recovered from lithium batteries was oxidized by acid leaching to obtain carbon black residue. The carbon black residue was washed, dried, and ground to an average particle size of less than 0.1 mm to obtain carbon black residue powder. 45 g of carbon black residue powder was mixed with 280 mL of 3.7% ammonium sulfate solution and stirred to obtain an aqueous carbon black residue solution. The aqueous carbon black residue solution was placed in a sealed container for heating and hydrothermally reacted at 185 °C for 2 h 13 min. After cooling and filtration, the filter residue was washed with dilute acid and dried to obtain ammonium sulfate-modified carbon black residue. (2) Preparation of nickel-cobalt-manganese-sodium mixed salt: The nickel-cobalt-manganese mixed salt prepared by battery recovery was mixed with sodium sulfate and ground to an average particle size of less than 100 µm to obtain a mixture. The mixture was uniformly mixed with a 3.41 wt% oxalic acid solution, subjected to solid-liquid separation and evaporated to remove water, heated to 425 °C in an inert atmosphere, held at constant temperature for 3 h 54 min, cooled, 0.34 mol / L of hydrochloric acid was added for pickling, washed and dried to obtain a nickel-cobalt-manganese-sodium mixed salt; where the mass ratio of sodium sulfate and the nickel-cobalt-manganese mixed salt = 5:17, and the solid-liquid ratio of the mixture to the oxalic acid solution was 10:65 g / mL. (3) Synthesis of polymetal-carbon based adsorbent: 22 g of nickel-cobalt-manganese-sodium mixed salt, 45 g of ammonium sulfate-modified carbon black residue, and 7 g of silicate clay were mixed and compacted to obtain a certain flake shape with a compaction density of 2.23 g / cm3, which was dried, heated to 485 °C in a nitrogen atmosphere, held at constant temperature for 2 h 12 min, and cooled to obtain a polymetal-carbon based adsorbent; where the mass ratio of nickel-cobalt-manganese-sodium mixed salt, ammonium sulfate modified carbon black residue and silicate clay = 35:70:2, 3. (4) Wastewater treatment by adsorbent adsorption: The wastewater produced by the preparation of the ternary precursor was settled, filtered, and heavily oxidized to obtain the primary treated wastewater, and the multi-metal and carbon-based adsorbent was added for adsorption treatment. After treatment, the adsorbent was soaked in 0.34 mol / L hydrochloric acid for desorption. After 5 adsorption-desorption treatments, the treated wastewater was sent to secondary treatment, and the adsorbent was reused for adsorption treatment again; where the solid-liquid ratio of adsorbent to wastewater was 1:9 kg / L. Figure 2 is an SEM image of the wastewater adsorbent prepared in this example. As can be seen in the figure, the adsorbent has a structure with a rough surface and internal pores. Example 3 A method for preparing the wastewater adsorbent and the wastewater treatment method were provided, and the specific process was: (1) Modification of carbon black residue: Battery powder recovered from lithium batteries was oxidized by acid leaching to obtain carbon black residue. The carbon black residue was washed, dried, and ground to an average particle size of less than 0.1 mm to obtain carbon black residue powder. 36 g of carbon black residue powder were mixed with 240 mL of 4.4% ammonium chloride solution and stirred to obtain an aqueous carbon black residue solution. The aqueous carbon black residue solution was placed in a sealed container for heating and hydrothermally reacted at 160 °C for 2 h 33 min. After cooling and filtration, the filter residue was washed with dilute acid and dried to obtain ammonium chloride-modified carbon black residue. (2) Preparation of nickel-cobalt-manganese-sodium mixed salt: The nickel-cobalt-manganese mixed salt prepared by battery recovery was mixed with sodium sulfate and ground to an average particle size of less than 100 µm to obtain a mixture. The mixture was uniformly mixed with a 6.33 wt% oxalic acid solution, subjected to solid-liquid separation and evaporated to remove water, heated to 430 °C in an inert atmosphere, held at a constant temperature for 3 h 34 min, cooled, 0.34 mol / L of hydrochloric acid was added for acid pickling, washed and dried to obtain a nickel-cobalt-manganese-sodium mixed salt; where the mass ratio of sodium sulfate and the nickel-cobalt-manganese mixed salt = 4:13, and the solid-liquid ratio of the mixture to the oxalic acid solution was 10:50g / mL. (3) Synthesis of multi-metal carbon-based adsorbent: 17 g of nickel-cobalt-manganese-sodium mixed salt, 36 g of ammonium chloride-modified carbon black residue, and 5 g of silicate clay were mixed and compacted to obtain a certain block shape with a compaction density of 2.07 g / cm3, which was dried, heated to 485 °C in a nitrogen atmosphere, held at constant temperature for 2 h 12 min, and cooled to obtain a polymetal-carbon-based adsorbent. (4) Wastewater treatment by adsorbent adsorption: The wastewater produced by the preparation of the ternary precursor was settled, filtered, and heavily oxidized to obtain the primary treated wastewater, and the multi-metal and carbon-based adsorbent was added for adsorption treatment. After treatment, the adsorbent was soaked in 0.34 mol / L hydrochloric acid for desorption. After 5 adsorption-desorption treatments, the treated wastewater was sent to secondary treatment, and the adsorbent was reused for adsorption treatment again; where the solid-liquid ratio of adsorbent to wastewater was 1:7 kg / L. Example 4 A method for preparing the wastewater adsorbent and the wastewater treatment method were provided, and the specific process was: (1) Modification of carbon black residue: Battery powder recovered from lithium batteries was oxidized by acid leaching to obtain carbon black residue. The carbon black residue was washed, dried, and ground to an average particle size of less than 0.1 mm to obtain carbon black residue powder. 25 g of carbon black residue powder were mixed with 200 mL of 5.3% ammonium chloride solution and stirred to obtain an aqueous carbon black residue solution. The aqueous carbon black residue solution was placed in a sealed container for heating and hydrothermally reacted at 160 °C for 3 and 8 min. After cooling and filtration, the filter residue was washed with dilute acid and dried to obtain ammonium chloride-modified carbon black residue. (2) Preparation of nickel-cobalt-manganese sodium mixed salt: The nickel-cobalt-manganese mixed salt prepared by battery recovery was mixed with sodium sulfate and ground to an average particle size of less than 100 µm to obtain a mixture. The mixture was uniformly mixed with a 6.12 wt% oxalic acid solution, subjected to solid-liquid separation and evaporated to remove water, heated to 430 °C in an inert atmosphere, held at a constant temperature for 3 h 17 min, cooled, 0.34 mol / L hydrochloric acid was added for acid pickling, washed and dried to obtain a nickel-cobalt-manganese-sodium mixed salt; where the mass ratio of sodium sulfate and the nickel-cobalt-manganese mixed salt = 5:15, and the solid-liquid ratio of the mixture to the oxalic acid solution was 10:50 g / mL. (3) Synthesis of polymetal-carbon based adsorbent: 8 g of nickel-cobalt-manganese-sodium mixed salt, 25 g of ammonium chloride-modified carbon black residue, and 3 g of silicic acid clay were mixed and compacted to obtain a certain block shape with a compaction density of 2.47 g / cm3, which was dried, heated to 485 °C in a nitrogen atmosphere, held at a constant temperature for 2 h 12 min, and cooled to obtain a polymetal-carbon based adsorbent. (4) Wastewater treatment by adsorbent adsorption: The wastewater produced by the preparation of the ternary precursor was settled, filtered, and heavily oxidized to obtain the primary treated wastewater, and the multi-metal and carbon-based adsorbent was added for adsorption treatment. After treatment, the adsorbent was soaked in 0.34 mol / L hydrochloric acid for desorption. After 5 adsorption-desorption treatments, the treated wastewater was sent to secondary treatment, and the adsorbent was reused for adsorption treatment again; where the solid-liquid ratio of adsorbent to wastewater was 1:10 g / L. Comparative Example 1 The difference between this comparative example and Example 1 is that the carbon black residue in step (1) is not modified. Comparative Example 2 The difference between this comparative example and Example 1 was that the nickel-cobalt-manganese-sodium mixed salt was not added in step (3). Comparative Example 3 The difference between this comparative example and Example 3 was that the nickel-cobalt-manganese-sodium mixed salt was not added in step (3). Table 1 The impurity content of wastewater before and after adsorption treatment of Examples 1-4 and Comparative Examples 1-3. Table 1 shows that, compared to Comparative Example 1, ammonia nitrogen removal in the wastewater of Examples 1–4 improved significantly after the ammonium salt modification. Furthermore, compared to Comparative Examples 2 and 3, nickel-cobalt-manganese-sodium mixed salt removal significantly improved in Examples 1–4 after the addition of the mixed salt. Examples of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the examples mentioned above. Within the scope of knowledge of those skilled in the art, various modifications may be made without departing from the purpose of the present invention. Furthermore, the examples of the present invention and the features in the examples may be combined with each other, provided there is no conflict.

Claims

1. A method for preparing a wastewater adsorbent, characterized in that it comprises the following steps: S1: mixing carbon black powder with ammonium salt solution, heating for the hydrothermal reaction and then filtering, washing the resulting filter residue with acid to obtain ammonium salt-modified carbon black; mixing nickel-cobalt-manganese mixed salt and sodium salt to obtain a mixture, mixing the mixture with an organic acid solution, evaporating to remove water and carrying out the heating reaction in an inert atmosphere; washing with acid to obtain nickel-cobalt-manganese-sodium mixed salt after the reaction; S2: mixing the nickel-cobalt-manganese-sodium mixed salt, ammonium salt-modified carbon black and a binding agent, compacting, drying and heating to obtain a multi-metal carbon-based adsorbent. 2.The preparation method according to claim 1, characterized in that in step S1, the carbon black powder is obtained by acid oxidation leaching of battery powder recovered from a lithium battery.

3. The preparation method according to claim 1, characterized in that in step S1, the ammonium salt solution is one or more of the following solutions: ammonium sulfate, ammonium bisulfate, ammonium carbonate, ammonium bicarbonate, ammonium chloride, ammonium phosphate, or ammonium dihydrogen phosphate; the solid-to-liquid ratio of the carbon black powder to the ammonium salt solution is 10-500 g / L, and the mass concentration of the ammonium salt solution is 0.1-30%.

4. The preparation method according to claim 1, characterized in that in step S1, the temperature of the hydrothermal reaction is 100-400 °C. Preferably, the hydrothermal reaction time is 1-10 h. 5.The preparation method according to claim 1, characterized in that in step S1, the nickel-cobalt-manganese mixed salt is prepared by battery recycling; preferably, the mass ratio of the sodium salt and the nickel-cobalt-manganese mixed salt is (1-10) : (0, 1-30).

6. The preparation method according to claim 1, characterized in that in step S1, the organic acid solution is one or more of oxalic acid, citric acid, acetic acid, formic acid, or acetic acid solution; the solid-to-liquid ratio of the mixture and the organic acid solution is 10: (50-200) g / mL, and the mass concentration of the organic acid solution is 1-40%.

7. The preparation method according to claim 1, characterized in that in step S1, the temperature of the heating reaction is 300-1100 °C; Preferably, the heating reaction time is 2-24 h. 8.The preparation method according to claim 1, characterized in that in step S2 the binding agent is one or more of calcium silicate, calcium alginate, clay silicate, or sodium aluminosilicate; preferably, the mass ratio of the nickel-cobalt-manganese-sodium mixed salt, the ammonium salt-modified carbon black, and the binder is (10-50) : (30-70) : (0, 1-8).

9. A wastewater adsorbent, characterized in that it is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the wastewater adsorbent according to claim 9 in the treatment of ternary precursor wastewater.

Images