Detailed Description
The technical scheme of the invention is further explained by combining the attached drawings.
Example 1 volume ratio of sodium hydroxide aqueous solution to galvanizing waste liquid to effect of purifying zinc waste liquid and performance of prepared zinc-iron catalytic material
Sodium hydroxide was weighed and dissolved in water to prepare a 0.5M aqueous solution of sodium hydroxide. The volume ratio of the aqueous sodium hydroxide solution to the zinc plating waste liquid is (1.25). And weighing expanded perlite, and grinding for 10 minutes to obtain expanded perlite powder. Respectively weighing the expanded perlite powder and the zinc-iron slurry according to the mass ratio of the expanded perlite powder to the zinc-iron slurry of 2.5, mixing, stirring and carrying out low-temperature plasma irradiation for 2 hours to obtain the zinc-iron catalytic slurry, wherein the stirring speed is 60rpm, the low-temperature plasma action voltage is 5kV, and the low-temperature plasma action atmosphere is oxygen. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purified liquid and zinc-iron catalytic precipitate, wherein the centrifugation speed is 3000rpm. And drying the zinc-iron catalytic precipitate at 50 ℃, and grinding into powder to obtain the zinc-iron catalytic material.
Sodium dichlorophenolate removal test: the solid-liquid ratio of the prepared zinc-iron catalytic material to the water containing the diclofenac sodium is 15g, 1L, the zinc-iron catalytic material is put into the water with the initial pH value of 1 and containing 50mM diclofenac sodium, and the mixture is stirred for 60min under the dark environment and the rotation speed of 120rpm, and then solid-liquid separation is carried out.
And (3) measuring the concentration of the diclofenac sodium in the water body: the concentration of the diclofenac sodium in the water body is determined by referring to a method of detecting diclofenac sodium in water environment by an LC-MS/MS method.
Calculating the removal rate of the diclofenac sodium in the water body: the removal rate of sodium dichlorophenolate in the water body is calculated according to the following equation (1), wherein R d Is the removal rate of sodium dichlorophenolate, c d0 And c dt The concentrations of diclofenac sodium in the solution before and after the adsorption experiment are shown respectively.
And (3) measuring the concentration of a target element in the galvanizing waste liquid: the concentrations of five target elements of zinc, copper, lead, iron and nickel in the galvanizing waste liquid are measured according to the inductively coupled plasma emission spectrometry for measuring 32 elements in water (HJ 776-2015).
Calculating the removal rate of the target elements in the galvanizing waste liquid: the removal rate of the target element in the zinc plating waste liquid is calculated according to the following equation (2), wherein R s Is the removal rate of the target element S (the target element S represents zinc, copper, lead, nickel and iron), c s0 And c st The concentrations of the target element S in the solution before and after the adsorption experiment are respectively. The test results are shown in Table 1.
TABLE 1 volume ratio of sodium hydroxide aqueous solution to zinc plating waste liquid for purifying zinc plating waste liquid and influence of prepared zinc-iron catalytic material on performance
As can be seen from table 1, when the volume ratio of the aqueous sodium hydroxide solution to the zinc plating waste liquid is less than 0.5 (as in table 1, when the volume ratio of the aqueous sodium hydroxide solution to the zinc plating waste liquid = 0.45. When the volume ratio of the sodium hydroxide aqueous solution to the zinc plating waste liquid is equal to 0.5 to 1.5 (as in table 1, the volume ratio of the sodium hydroxide aqueous solution to the zinc plating waste liquid =0.5, 1:1, 1.5). With the lapse of the low-temperature plasma irradiation time, the oxygen radicals may further dehydrogenate the metal hydroxide to convert into a binary metal oxide. Finally, the removal rate of zinc in the galvanizing waste liquid is more than 86%, the removal rate of iron is more than 85%, the removal rate of copper is more than 91%, the removal rate of lead is more than 92%, the removal rate of nickel is more than 90%, and the removal rate of diclofenac sodium in the water body is more than 82%. When the volume ratio of the sodium hydroxide aqueous solution to the zinc plating waste liquid is greater than 1.5 (as shown in table 1, the volume ratio of the sodium hydroxide aqueous solution to the zinc plating waste liquid is = 1.6. Therefore, in summary, combining the benefit and the cost, when the volume ratio of the sodium hydroxide aqueous solution to the zinc plating waste liquid is equal to 0.5-1.5.
Example 2 quality ratio of expanded perlite powder and zinc-iron slurry to effect of purifying waste galvanizing solution and performance of prepared zinc-iron catalytic material
Sodium hydroxide was weighed and dissolved in water to prepare a 2.75M aqueous solution of sodium hydroxide. And (2) mixing the sodium hydroxide aqueous solution with the galvanizing waste liquid according to the volume ratio of the sodium hydroxide aqueous solution to the galvanizing waste liquid of 1.5, and stirring for 1 hour to obtain the zinc-iron slurry. And weighing the expanded perlite, and grinding for 20 minutes to obtain expanded perlite powder. The method comprises the following steps of (1) weighing the expanded perlite powder and the zinc-iron slurry according to the mass ratio of the expanded perlite powder to the zinc-iron slurry of 1. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purified liquid and zinc-iron catalytic precipitate, wherein the centrifugation speed is 7500rpm. And drying the zinc-iron catalytic precipitate at the temperature of 100 ℃, and grinding the zinc-iron catalytic precipitate into powder to obtain the zinc-iron catalytic material.
Sodium dichlorophenolate removal test: adding the zinc-iron catalytic material into a water body with the initial pH of 7 and containing 50mM of diclofenac sodium according to the solid/liquid ratio of the prepared zinc-iron catalytic material to the water body containing the diclofenac sodium of 15g.
The concentration determination of sodium dichlorophenolate in the water body, the calculation of the removal rate of sodium dichlorophenolate in the water body, the concentration determination of the target element in the galvanizing waste liquid and the calculation of the removal rate of the target element in the galvanizing waste liquid are the same as those in the embodiment 1.
TABLE 2 Mass ratio of expanded perlite powder to zinc-iron slurry influences on the purification effect of the waste liquid from galvanizing and the performance of the prepared zinc-iron catalytic material
As can be seen from table 2, when the mass ratio of the expanded perlite powder to the zinc-iron slurry is less than 2.5 (as in table 2, the mass ratio of the expanded perlite powder to the zinc-iron slurry is =2, 100, 1, 100, and lower ratios not listed in table 2), the expanded perlite powder is less, the adsorption amount of the free heavy metal ions and the precipitation conversion efficiency in the galvanizing waste liquid are reduced, and the removal rate of zinc, iron, copper, lead, and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenate in the water body are all significantly reduced as the mass ratio of the expanded perlite powder to the zinc-iron slurry is reduced. When the mass ratio of the expanded perlite powder to the zinc-iron slurry is equal to 2.5-12.5 (as in table 2, the mass ratio of the expanded perlite powder to the zinc-iron slurry is =2.5, 100, 7.5, 100, 12.5). The oxygen free radicals can increase the surface activity of the expanded perlite powder and improve the surface hydroxyl loading capacity of the expanded perlite powder. The expanded perlite powder with improved surface activity can strengthen the adsorption of free heavy metal ions. Finally, the zinc removal rate, the iron removal rate, the copper removal rate, the lead removal rate, the nickel removal rate and the sodium dichlorophenolate removal rate in the galvanizing waste liquid are all more than 91%, 90%, 94%, 95% and 89%, respectively. When the mass ratio of the expanded perlite powder to the zinc-iron slurry is greater than 12.5 (as shown in table 2, when the mass ratio of the expanded perlite powder to the zinc-iron slurry is =13, 100, 14, 15, and 100 and higher ratios not listed in table 2), the expanded perlite powder is too much, and too much oxygen radicals are consumed by the expanded perlite powder, so that the generation amounts of heavy metal oxides and binary metal oxides are reduced, and the removal rate of zinc, iron, copper, lead and nickel in the zinc plating waste liquid and the removal rate of sodium dichlorophenate in the water body are remarkably reduced as the mass ratio of the expanded perlite powder to the zinc-iron slurry is further increased. Therefore, in summary, combining the benefit and the cost, when the mass ratio of the expanded perlite powder to the zinc-iron slurry is equal to 2.5-12.5.
Example 3 Effect of Low temperature plasma action Voltage on Zinc plating waste liquid purification Effect and Performance of prepared Zinc-iron catalytic Material
Sodium hydroxide was weighed and dissolved in water to prepare a 5M aqueous solution of sodium hydroxide. And (3) mixing the sodium hydroxide aqueous solution with the galvanizing waste liquid according to the volume ratio of the sodium hydroxide aqueous solution to the galvanizing waste liquid of 1.5, and stirring for 1.5 hours to obtain the zinc-iron slurry. And weighing the expanded perlite, and grinding for 30 minutes to obtain expanded perlite powder. Respectively weighing expanded perlite powder and zinc-iron slurry according to the mass ratio of the expanded perlite powder to the zinc-iron slurry of 12.5. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purification liquid and zinc-iron catalytic precipitation, wherein the centrifugation speed is 12000rpm. And drying the zinc-iron catalytic precipitate at 150 ℃, and grinding into powder to obtain the zinc-iron catalytic material.
Sodium dichlorophenolate removal test: the solid-liquid ratio of the prepared zinc-iron catalytic material to the water containing the diclofenac sodium is 15g, 1L, the zinc-iron catalytic material is put into the water with the initial pH value of 13 and containing 50mM diclofenac sodium, and the mixture is stirred for 60min under the dark environment and the rotation speed of 120rpm, and then solid-liquid separation is carried out.
The concentration determination of sodium dichlorophenolate in the water body, the calculation of the removal rate of sodium dichlorophenolate in the water body, the concentration determination of the target element in the galvanizing waste liquid and the calculation of the removal rate of the target element in the galvanizing waste liquid are the same as those in the embodiment 1.
TABLE 3 influence of low-temperature plasma action voltage on the purification effect of zinc-plating waste liquid and the performance of the prepared zinc-iron catalytic material
As can be seen from table 3, when the low-temperature plasma applied voltage is less than 5kV (as in table 3, when the low-temperature plasma applied voltage =4.5kV, 3.5kV, 2.5kV and lower values not listed in table 3), oxygen radicals are generated during the low-temperature plasma irradiation process less, the surface activity of the expanded perlite powder is not significantly improved, and the generation amounts of heavy metal oxides and binary metal oxides are reduced, so that the removal rates of zinc, iron, copper, lead, and nickel in the zinc plating waste liquid and the removal rate of sodium dichlorophenate in the water body are all significantly reduced along with the reduction of the low-temperature plasma applied voltage. When the low-temperature plasma applied voltage is 5 to 50kV (as in table 3, low-temperature plasma applied voltage =5kV, 27.5kV, 50 kV), oxygen is ionized and dissociated in the discharge channel during the low-temperature plasma irradiation process, and oxygen radicals are generated. The oxygen free radicals can increase the surface activity of the expanded perlite powder and improve the surface hydroxyl loading capacity of the expanded perlite powder. Meanwhile, the oxygen free radicals can also combine heavy metal ions with oxygen to induce the generation of heavy metal oxides. With the lapse of the low-temperature plasma irradiation time, the oxygen radicals may further dehydrogenate the metal hydroxide to convert into a binary metal oxide. Finally, the zinc removal rate, the iron removal rate, the copper removal rate, the lead removal rate, the nickel removal rate and the sodium dichlorophenolate removal rate in the galvanizing waste liquid are respectively greater than 95%, 97%, 98% and 94%. When the low-temperature plasma action voltage is more than 50kV (as shown in the table 3, when the low-temperature plasma action voltage =52kV, 55kV and 60kV, and higher values which are not listed in the table 3), the removal rate of zinc, iron, copper, lead and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenolate in the water body are not obviously changed along with the further increase of the low-temperature plasma action voltage. Therefore, in summary, the benefit and the cost are combined, and when the low-temperature plasma action voltage is equal to 5-50 kV, the method is most beneficial to the purification of the galvanizing waste liquid and the preparation of the zinc-iron catalytic material.
Example 4 influence of Low-temperature plasma irradiation time on the purification effect of zinc plating waste liquid and the performance of the prepared zinc-iron catalytic material
Sodium hydroxide was weighed and dissolved in water to prepare a 5M aqueous solution of sodium hydroxide. And (3) mixing the sodium hydroxide aqueous solution with the galvanizing waste liquid according to the volume ratio of the sodium hydroxide aqueous solution to the galvanizing waste liquid of 1.5, and stirring for 1.5 hours to obtain the zinc-iron slurry. And weighing the expanded perlite, and grinding for 30 minutes to obtain expanded perlite powder. Respectively weighing the expanded perlite powder and the zinc-iron slurry according to the mass ratio of 12.5. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purified liquid and zinc-iron catalytic precipitate, wherein the centrifugation speed is 12000rpm. And drying the zinc-iron catalytic precipitate at 150 ℃, and grinding into powder to obtain the zinc-iron catalytic material.
The sodium dichlorophenolate removal test was the same as in example 2. The concentration determination of sodium dichlorophenolate in the water body, the calculation of the removal rate of sodium dichlorophenolate in the water body, the concentration determination of the target element in the galvanizing waste liquid and the calculation of the removal rate of the target element in the galvanizing waste liquid are the same as those in the embodiment 1.
TABLE 4 influence of low-temperature plasma irradiation time on the purification effect of the zinc-plating waste liquid and the performance of the prepared zinc-iron catalytic material
As can be seen from table 4, when the low-temperature plasma irradiation time is less than 2 hours (as in table 4, the low-temperature plasma irradiation time =1.8 hours, 1.5 hours, 1 hour, and lower values not listed in table 4), the low-temperature plasma irradiation time is too short, the generated oxygen radicals are less, the surface activity of the expanded perlite powder is not significantly improved, and the generation amount of the binary metal oxide is reduced, so that the removal rate of zinc, iron, copper, lead, and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenolate in the water body are both significantly reduced with the reduction of the low-temperature plasma irradiation time. When the low-temperature plasma irradiation time is equal to 2-6 hours (as shown in table 4, the low-temperature plasma irradiation time =2 hours, 4 hours, 6 hours), in the low-temperature plasma irradiation process, oxygen is ionized and dissociated in the discharge channel to generate oxygen radicals, and the oxygen radicals can increase the surface activity of the expanded perlite powder, improve the surface hydroxyl loading capacity of the expanded perlite powder, enhance the adsorption of free heavy metal ions by the expanded perlite powder with improved surface activity, and simultaneously, the oxygen radicals can combine the heavy metal ions with oxygen to induce the generation of heavy metal oxides; with the lapse of the low-temperature plasma irradiation time, the oxygen radicals may further dehydrogenate the metal hydroxide to convert into a binary metal oxide. Because the zinc and iron ion content in the galvanizing waste liquid is far higher than that of other heavy metal ions, under the full action of oxygen free radicals, the metal hydroxide is mainly converted into a zinc-iron binary oxide catalytic material doped with lead, copper and nickel. Finally, the zinc removal rate, the iron removal rate, the copper removal rate, the lead removal rate, the nickel removal rate and the sodium dichlorophenolate removal rate in the galvanizing waste liquid are respectively greater than 93%, 92%, 95%, 96%, 97% and 93%. When the low-temperature plasma irradiation time is longer than 6 hours (as shown in table 4, the low-temperature plasma irradiation time =2 hours, 4 hours, 6 hours and higher values not listed in table 4), the low-temperature plasma irradiation time is too long, and shock waves and microwaves released in the low-temperature plasma action process enable lead, copper and nickel doped zinc-iron binary oxides to be dissolved back, so that the purification effect of the galvanizing waste liquid is reduced, and the removal rate of zinc, iron, copper, lead and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenate in the water body are reduced along with the further increase and change of the low-temperature plasma irradiation time. Therefore, in summary, the benefit and the cost are combined, and when the low-temperature plasma irradiation time is equal to 2-6 hours, the method is most beneficial to the purification of the galvanizing waste liquid and the preparation of the zinc-iron catalytic material.
Comparative example 1 influence of different low-temperature plasma action atmospheres on purification effect of galvanizing waste liquid and performance of prepared zinc-iron catalytic material
Sodium hydroxide was weighed and dissolved in water to prepare a 5M aqueous solution of sodium hydroxide. And (3) mixing the sodium hydroxide aqueous solution with the galvanizing waste liquid according to the volume ratio of the sodium hydroxide aqueous solution to the galvanizing waste liquid of 1.5, and stirring for 1.5 hours to obtain the zinc-iron slurry. And weighing the expanded perlite, and grinding for 30 minutes to obtain expanded perlite powder. Respectively weighing the expanded perlite powder and the zinc-iron slurry according to the mass ratio of 12.5. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purified liquid and zinc-iron catalytic precipitate, wherein the centrifugation speed is 12000rpm. And drying the zinc-iron catalytic precipitate at 150 ℃, and grinding into powder to obtain the zinc-iron catalytic material.
The sodium dichlorophenolate removal test was the same as in example 2. The concentration determination of sodium dichlorophenolate in the water body, the calculation of the removal rate of sodium dichlorophenolate in the water body, the concentration determination of the target element in the galvanizing waste liquid and the calculation of the removal rate of the target element in the galvanizing waste liquid are the same as those in the embodiment 1.
TABLE 5 influence of different low-temperature plasma action atmospheres on the purification effect of the zinc plating waste liquid and the performance of the prepared zinc-iron catalytic material
As can be seen from Table 5, the removal rate of zinc, iron, copper, lead and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenolate in the water body, which are realized by taking oxygen as the low-temperature plasma action atmosphere, are far higher than the removal effect realized by taking air, nitrogen and argon as the low-temperature plasma action atmosphere.
Comparative example 2 different comparative processes affect the purification effect of the galvanizing waste liquid and the performance of the prepared zinc-iron catalytic material
The treatment process comprises the following steps: sodium hydroxide was weighed and dissolved in water to prepare a 5M aqueous solution of sodium hydroxide. And (3) mixing the sodium hydroxide aqueous solution with the galvanizing waste liquid according to the volume ratio of the sodium hydroxide aqueous solution to the galvanizing waste liquid of 1.5, and stirring for 1.5 hours to obtain the zinc-iron slurry. And weighing the expanded perlite, and grinding for 30 minutes to obtain expanded perlite powder. Respectively weighing the expanded perlite powder and the zinc-iron slurry according to the mass ratio of 12.5. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purified liquid and zinc-iron catalytic precipitate, wherein the centrifugation speed is 12000rpm. And drying the zinc-iron catalytic precipitate at 150 ℃, and grinding into powder to obtain the zinc-iron catalytic material.
Comparative process 1: sodium hydroxide was weighed and dissolved in water to prepare a 5M aqueous solution of sodium hydroxide. And (3) mixing the sodium hydroxide aqueous solution with the galvanizing waste liquid according to the volume ratio of the sodium hydroxide aqueous solution to the galvanizing waste liquid of 1.5, and stirring for 1.5 hours to obtain the zinc-iron slurry. And (3) carrying out low-temperature plasma irradiation on the zinc-iron slurry for 6 hours to obtain the zinc-iron catalytic slurry, wherein the stirring speed is 360rpm, the acting voltage of the low-temperature plasma is 50kV, and the acting atmosphere of the low-temperature plasma is oxygen. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purification liquid and zinc-iron catalytic precipitation, wherein the centrifugation speed is 12000rpm. And (3) drying the zinc-iron catalytic precipitate at 150 ℃, and grinding into powder to obtain the zinc-iron catalytic material.
Comparative process 2: respectively weighing the expanded perlite powder and the galvanizing waste liquid according to the mass ratio of the expanded perlite powder to the galvanizing waste liquid of 12.5, mixing, stirring and carrying out low-temperature plasma irradiation for 6 hours to obtain the zinc-iron catalytic slurry, wherein the stirring speed is 360rpm, the low-temperature plasma action voltage is 50kV, and the low-temperature plasma action atmosphere is oxygen. And centrifuging the zinc-iron catalytic material slurry to obtain waste liquid purified liquid and zinc-iron catalytic precipitate, wherein the centrifugation speed is 12000rpm. And drying the zinc-iron catalytic precipitate at 150 ℃, and grinding into powder to obtain the zinc-iron catalytic material.
Comparative process 3: sodium hydroxide was weighed and dissolved in water to prepare a 5M aqueous solution of sodium hydroxide. And (3) mixing the sodium hydroxide aqueous solution with the galvanizing waste liquid according to the volume ratio of the sodium hydroxide aqueous solution to the galvanizing waste liquid of 1.5, and stirring for 1.5 hours to obtain the zinc-iron slurry. And weighing the expanded perlite, and grinding for 30 minutes to obtain expanded perlite powder. Respectively weighing expanded perlite powder and zinc-iron slurry according to the mass ratio of 12.5. And drying the zinc-iron precipitate at 150 ℃, and grinding the zinc-iron precipitate into powder to obtain the zinc-iron catalytic material.
The sodium dichlorophenolate removal test was the same as in example 2. The concentration determination of the diclofenac sodium in the water body, the calculation of the removal rate of the diclofenac sodium in the water body, the concentration determination of the target element in the galvanizing waste liquid and the calculation of the removal rate of the target element in the galvanizing waste liquid are all the same as those in the embodiment 1.
TABLE 6 influence of different comparative processes on the purification effect of the waste galvanizing solution and the performance of the prepared zinc-iron catalytic material
As can be seen from Table 6, the removal rate of zinc, iron, copper, lead and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenolate in the water body, which are realized by the treatment process of the invention, are much higher than the removal effects realized by the comparative processes 1, 2 and 3. The removal rate of zinc, iron, copper, lead and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenolate in the water body, which are realized by the treatment process, are higher than the sum of the removal rates of zinc, iron, copper, lead and nickel and the removal rate of sodium dichlorophenolate in the water body, which are realized by the comparison process 1 and the comparison process 2. The removal rate of zinc, iron, copper, lead and nickel in the galvanizing waste liquid and the removal rate of sodium dichlorophenolate in the water body, which are realized by the treatment process, are higher than the sum of the removal rates of zinc, iron, copper, lead and nickel and the removal rate of sodium dichlorophenolate in the water body, which are realized by the comparison process 2 and the comparison process 3.