CN114988514A

CN114988514A - Method for removing penicillin potassium in water body by using composite biochar and application

Info

Publication number: CN114988514A
Application number: CN202210941168.7A
Authority: CN
Inventors: 龙建友; 邓一荣; 陈子楷; 李笛; 莫健莹; 吴翠琴; 周颖; 李伙生; 肖唐付; 黎洋凯
Original assignee: Guangzhou University
Current assignee: Guangzhou University
Priority date: 2022-08-08
Filing date: 2022-08-08
Publication date: 2022-09-02
Anticipated expiration: 2042-08-08
Also published as: CN114988514B

Abstract

The invention discloses a method for removing penicillin potassium in water by activating persulfate through composite biochar, which is used for removing penicillin potassium in water by utilizing the adsorption effect of the composite biochar. The composite biochar is orange peel biochar loaded with zero-valent manganese, which is prepared from orange peel serving as a raw material by a carbothermic method. The invention also provides application of the composite biochar activated persulfate in removal of penicillin potassium in water, namely adjusting the pH value of the water to 3-9, adjusting the water temperature to 15-35 ℃, and adding 0.5g/L of composite biochar and 1-40mmol/L of persulfate into the water to remove penicillin potassium in the water. The composite biochar has the advantages of simple preparation process, low price of production raw materials and high penicillin potassium removal rate.

Description

Method for removing penicillin potassium in water body by using composite biochar and application

Technical Field

The invention belongs to the technical field of sewage treatment, relates to application of biochar in sewage treatment, and particularly relates to a method for removing penicillin potassium in a water body by using composite biochar and application of the composite biochar.

Background

The antibiotic is a substance which is generated in the microbial reproduction process and has the function of inhibiting the growth of microorganisms, wherein penicillin as the antibiotic with definite curative effect, low price and guaranteed quality occupies larger market share in the antibiotic market of China.

The antibiotics with too high concentration can directly remain in the bodies of animals and plants and in the environment such as soil and the like, and directly enter the natural water body environment through the daily metabolism, substance circulation and other ways of organisms to form antibiotic wastewater, and the antibiotic wastewater has the effect of inhibiting or poisoning the growth of microorganisms and is difficult to biodegrade. The adsorption method has the advantages of low cost, good removal effect, simple operation, cyclic regeneration and the like, and becomes one of the most effective methods for treating antibiotic wastewater at present.

Biochar is an aromatic compound which is rich in carbon elements and porous in physical structure and is generated by low-temperature slow pyrolysis of biomass (animals, plants, microorganisms and the like) under the anoxic or anaerobic condition. As an environment-friendly material with low price and excellent adsorption performance, the biological carbon is widely applied to the aspect of environmental management, and the biological carbon also becomes a research hotspot in the field of environmental remediation due to the advantages of environmental friendliness, strong reproducibility and the like. The biochar has large specific surface area, high porosity and rich functional groups, so the biochar has good adsorption and removal effects on various environmental pollutants. As a novel environment-friendly material, the biochar is widely applied to adsorption and degradation of antibiotics.

In recent years, although biochar has been increasingly studied for use in the removal of organic wastewater, it is inevitably negatively charged, and therefore, the adsorption efficiency is not high. Therefore, the invention provides a technology for treating antibiotics in water based on a composite material taking biochar as a carrier.

Disclosure of Invention

The invention aims to remove penicillin potassium in water by activating persulfate through zero-valent manganese loaded composite biochar.

In order to achieve the purpose, the invention provides application of composite biochar in removing penicillin potassium in a water body, wherein the composite biochar and persulfate are added into the water body with the penicillin potassium content of 50mg/L, the adding amount of the composite biochar is 0.5g/L, and the adding amount of the persulfate is 1-40 mmol/L.

The composite biochar is orange peel biochar prepared from orange peel serving as a material by a carbothermic method and loaded with zero-valent manganese, and the specific preparation method of the orange peel biochar comprises the following steps: drying orange peel at 60 ℃, crushing and sieving with a 100-mesh sieve, filling the sieved powder into a ark, heating to 550 ℃ at a heating rate of 6.25 ℃/min in a tubular furnace with an initial temperature of 50 ℃, keeping the temperature for pyrolysis for 2 hours, carrying out nitrogen protection at an air flow of 0.6L/min, and taking out the orange peel biochar material after cooling to room temperature.

The method for loading zero-valent manganese on the orange peel biochar comprises the following steps: adding the orange peel biochar into a manganese sulfate solution, extracting the sodium borohydride solution into the manganese sulfate solution by using a constant flow pump under the stirring condition, continuing to react, standing and precipitating after extracting the sodium borohydride solution, cleaning the obtained precipitate with anhydrous water, drying in vacuum, sieving, sealing and storing, and placing in a dryer for later use.

Specifically, penicillin potassium particles are adsorbed on the surface of the composite biochar, and are aggregated on the surface of the biochar to form aggregates.

Specifically, magnesium or calcium ions coexisting in the water body with the penicillin potassium content of 50mg/L have a promoting effect on the removal of the penicillin potassium. The content of the magnesium or calcium ions in the water body is 0.01-0.1 mol/L.

Preferably, the reaction temperature of the composite biochar activated persulfate in a water body with the penicillin potassium content of 50mg/L is 35 ℃, the reaction time is 150min, the pH is 3 or 9, the adding amount of the composite biochar is 0.5g/L, the adding amount of the persulfate is 40mmol/L, and the concentration of magnesium or calcium ions is 0.1 mol/L.

The invention also provides a method for removing the penicillin potassium in the water body, which comprises the following steps: adding composite biochar and persulfate into a water body, activating the persulfate by the composite biochar to remove penicillin potassium in the water body, wherein the adding amount of the composite biochar is 0.5g/L and the adding amount of the persulfate is 1-40mmol/L in the water body with the penicillin potassium content of 50 mg/L.

By implementing the technical scheme of the invention, the following beneficial effects can be achieved:

(1) the composite biochar disclosed by the invention has the advantages that the main raw materials are orange peel and persulfate, the raw material cost is low, and the collection is easy.

(2) The composite biochar provided by the invention can realize the removal rate of the penicillin potassium in the water body of 85 percent at most.

Drawings

Figure 1 is the effect of the initial pH on the penicillin potassium removal.

FIG. 2 shows the effect of persulfate additions on the removal of potassium penicillin.

Figure 3 is the effect of temperature on the removal effect of penicillin potassium.

FIG. 4 shows the effect of coexisting ions on penicillin potassium removal.

FIG. 5 is the adsorption isotherm curve of composite biochar for removing penicillin potassium.

FIG. 6 is the adsorption kinetics curve of composite biochar for 10mg/L removal of penicillin potassium.

FIG. 7 is the adsorption kinetics curve of composite biochar for 50mg/L removal of penicillin potassium.

FIG. 8 is the adsorption kinetics curve of composite biochar for 100mg/L removal of penicillin potassium.

FIG. 9 is the scanning electron microscope images before and after adsorption of the composite biochar. (A) The scanning electron microscope images before and after the biological carbon adsorption are shown in (C), (B) and (D).

FIG. 10 is an infrared absorption spectrum before and after adsorption of composite biochar.

FIG. 11 shows XPS total spectra before and after adsorption on composite biochar.

FIG. 12 is a graph of O1s before adsorption of composite biochar.

FIG. 13 is a graph of O1s after adsorption of composite biochar.

FIG. 14 is a map of Mn2p before adsorption of composite biochar.

FIG. 15 is a Mn2p spectrum of composite biochar after adsorption.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

In the embodiment, orange peel and persulfate are used as raw materials to prepare the zero-valent manganese-loaded composite biochar.

Drying a proper amount of cleaned orange peel at 60 ℃, crushing, sieving by a 100-mesh sieve, filling the sieved powder into a square boat, heating to 550 ℃ in a tubular furnace with the initial temperature of 50 ℃ at the heating rate of 6.25 ℃/min, keeping the temperature for pyrolysis for two hours, introducing nitrogen (0.6L/min) for protection, taking out the orange peel biochar material after normal cooling to room temperature, and storing in a dryer for later use.

Weighing 3.07g of manganese sulfate and 3.5g of sodium borohydride (excessive) and respectively dissolving in 100mL of pure water, then weighing 1g of biochar and adding into a manganese sulfate solution, pumping the sodium borohydride solution into the manganese sulfate solution at the speed of 10mL/min by using a constant flow pump under the stirring condition, continuously reacting the solution for 20min after extracting the sodium borohydride solution, and then standing and precipitating for 10 min; and pouring out the supernatant, washing the obtained precipitate for 5 times by using oxygen-free water, and then putting the precipitate into a vacuum drying oven for low-temperature drying for 48 hours. And filtering the dried composite biochar by using a 100-mesh sieve, sealing and storing the biochar, and placing the biochar in a dryer for later use.

Example 2

This example provides an adsorption test of zero-valent manganese loaded composite biochar on penicillin potassium in solution. The preparation of the zero-valent manganese-loaded composite biochar used is described in example 1.

(1) Effect of initial pH on penicillin Potassium removal

200mL of 50mg/L penicillin potassium solution is prepared, then the initial pH of the penicillin potassium solution is adjusted to 3, 5, 7 and 9 by using HCl and NaOH solutions with appropriate concentrations, 0.1g of composite biochar is added, reaction is carried out for 150min at the temperature of 25 ℃, and then filtration sampling is carried out through a 0.22-micron filter membrane to determine the content of the penicillin potassium. The results are shown in FIG. 1.

As can be seen from fig. 1, the removal efficiency of potassium penicillin increases with the increase of pH, and at pH 3 and pH 9, the removal efficiency of potassium penicillin can reach more than 70%, which indicates that potassium penicillin is easier to be removed in the case of strong acid or strong base.

(2) Influence of persulfate addition on penicillin potassium removal effect

Preparing a penicillin potassium solution with the concentration of 50mg/L, adjusting the adding amount of the composite biochar to 0.5g/L, adjusting the pH value to 3 by using HCl and NaOH, dropwise adding persulfate by using a liquid-transferring gun, setting the concentration gradient of the persulfate to be 1, 2, 5, 10, 20 and 40mmol/L, reacting for 150min at the temperature of 25 ℃, filtering and sampling by using a 0.22 mu m filter membrane after the reaction is finished, and determining the content of the penicillin potassium. The results are shown in FIG. 2.

It can be seen from fig. 2 that the overall removal efficiency of penicillin potassium increases with the increase of the persulfate addition amount, under the condition of low-concentration persulfate addition amount, the improvement effect of persulfate on the removal efficiency of penicillin potassium is not obvious, and under the condition of high-concentration persulfate addition amount, the removal efficiency of penicillin potassium rapidly increases with the increase of persulfate addition amount, and the removal rate of penicillin potassium can reach about 85% under the condition of 40 mmol/L.

(3) Influence of temperature on the removal effect of penicillin potassium

Preparing 200mL of a penicillin potassium solution with the concentration of 50mg/L, adjusting the initial pH value of the penicillin potassium solution to 3 by using HCl and NaOH solutions with proper concentrations, adding 0.1g of composite biochar, setting the dosage of persulfate at 40mmol/L, setting the temperature gradient at 15 ℃, 20 ℃, 25 ℃, 30 ℃ and 35 ℃, reacting for 150min, filtering and sampling by using a 0.22-micron filter membrane, and determining the content of the penicillin potassium. The results are shown in FIG. 3.

As can be seen from FIG. 3, in the temperature range of 25 ℃ to 35 ℃, the high temperature is more beneficial to the removal of the potassium penicillin, the removal efficiency of the potassium penicillin is increased along with the increase of the temperature, and the removal efficiency can reach about 85% under the condition of 35 ℃.

(4) Effect of coexisting cations on penicillin Potassium removal

Preparing a penicillin potassium solution with the concentration of 50mg/L, adding the composite biochar in an amount of 0.5g/L, adjusting the pH to 3 by using HCl and NaOH, adding persulfate in an amount of 40mmol/L, and adding NaCl and CaCl with three concentrations (0.01, 0.05 and 0.1 mol/L) into the solution ₂ 、MgCl ₂ And setting comparison and reaction for 150min at 25 deg.c, filtering with 0.22 micron filtering film and sampling to determine the content of penicillin potassium. The results are shown in FIG. 4.

As can be seen from FIG. 4, the Na ion adsorption of penicillin potassium is shown as an inhibition effect, and the rest Mg and Ca ions are more beneficial to the removal of penicillin potassium.

Example 3

The embodiment provides adsorption isotherm analysis, kinetic analysis and characterization technical analysis of penicillin potassium adsorption by the zero-valent manganese-loaded composite biochar. The preparation of the zero-valent manganese-loaded composite biochar used is described in example 1.

(1) Composite biochar adsorption isotherm analysis

Under the condition of constant temperature, the relation between equilibrium concentration and adsorption capacity can be measured through an adsorption isotherm, the experiment adopts Langmuir and Freundlich models to fit the experiment result, and the model formula is as follows:

in the formula, q _e The adsorption capacity (mg/g) of the composite biochar to the penicillin potassium; q. q.s _m Maximum adsorption (mg/g); c. C _e The mass concentration (mg/L) of the penicillin potassium in the solution at the adsorption equilibrium; k is a radical of _L 、k _P And n are constants in the adsorption model.

Preparing penicillin potassium solution with the concentration of 10, 20, 50, 100, 150, 200 and 300mg/L respectively, adjusting the adding amount of the composite biochar to be 0.5g/L, adjusting the adding amount of the persulfate to be 40mmol/L, adjusting the pH to 3 by using HCl and NaOH, adjusting the adding amount of the persulfate to be 40mmol/L, reacting for 150min at the temperature of 25 ℃, filtering and sampling by using a 0.22 mu m filter membrane, and determining the content of the penicillin potassium. The results are shown in table 1 and fig. 5.

TABLE 1 adsorption model fitting parameter Table

As can be seen from table 1 and fig. 5, the adsorption capacity gradually increased with increasing potassium penicillin concentration. Correlation coefficient R of Freundlich model ² Correlation coefficient R of = 0.983/Langmuir model ² =0.981, so the Freundlich model is more suitable for the adsorption process of penicillin potassium by composite biochar, which indicates that the adsorption of the composite biochar is multilayer adsorption occurring on heterogeneous surfaces.

(2) Composite charcoal adsorption kinetic analysis

The possible adsorption mechanism between the composite biochar and the penicillin potassium is explained by fitting a primary kinetic model and a secondary kinetic model. The kinetic experiment reflects the change of the relation between the adsorption rate and the adsorption time. The quasi-first order kinetic equation and the quasi-second order kinetic equation are as follows:

in the formula, q _e To balance the adsorption rate (mg/g); q. q of _t Represents the adsorption capacity (mg/g) of the composite biochar to the penicillin potassium at t time; k is a radical of ₁ 、k ₂ Are respectively used for h ^-1 、g·mg ^-1 ·h ^-1 Expressed, the meaning is a constant of the kinetic reaction equation.

Preparing 200ml of penicillin potassium solution with the concentration of 50mg/L, adding 0.1g of composite biochar into the solution, setting the dosage of persulfate to be 40mmol/L, adjusting the pH to 3 by using HCl and NaOH, setting the dosage of persulfate to be 40mmol/L, setting the sampling time to be 1, 2, 5, 10, 20, 30, 60, 120, 150, 240, 300 and 480min after the reaction starts, filtering and sampling through a 0.22 mu m filter membrane, and measuring the content of penicillin potassium. The results are shown in table 2, fig. 6, fig. 7, and fig. 8.

TABLE 2 adsorption kinetics fitting parameter Table

As can be seen from the table 2, the figure 6, the figure 7 and the figure 8, the fitting parameters of the primary and the secondary dynamic models of the composite biochar have larger difference under the conditions of different concentrations of the three penicillin potassium solutions, and the fitting correlation coefficient R of the primary dynamic model is larger at low concentration ² Only 0.56, the fitting effect of the first-stage dynamic model on the adsorption test is not good, and a certain difference exists between the equilibrium adsorption quantity obtained by the first-stage dynamic model and the actual adsorption quantity. The fitting parameters of the secondary dynamics model are obviously higher than those of the primary dynamics, and the fitting correlation coefficient R of the secondary dynamics in the high-concentration penicillin potassium solution is obtained ² The adsorption rate of the composite biochar on the penicillin potassium can reach more than 0.95, so that the adsorption of the composite biochar on the penicillin potassium is more in line with a quasi-second order kinetic model.

(3) Characterization technical analysis of materials before and after composite charcoal adsorbs penicillin potassium

For the surface characteristic analysis of the composite biochar, the morphology and the structure of the material before and after adsorption are mainly observed through SEM, and the surface functional groups of the material before and after adsorption are measured through FT-IR; the changes of the forms and the contents of the relevant elements and functional groups before and after adsorption are analyzed by XPS.

FIG. 9 is a scanning electron microscope image before and after adsorption of the composite biochar, and the microstructure of the composite biochar is observed by different times of magnification of a scanning electron microscope. As can be seen from FIG. 9, the composite biochar material in the figure has a large number of pore structures, the total volume of micropores is also large, the orange peel biochar surface has a large number of similar net structures, and the micropores are densely distributed on the surface. Comparison of scanning electron microscope images before and after adsorption shows that a plurality of spherical substances are added on the surface of the adsorbed composite biochar, which indicates that the surface of the composite biochar adsorbs new substances and has a certain adsorption effect on penicillin potassium.

FIG. 10 is an infrared absorption spectrum before and after adsorption of the composite biochar, and by comparing infrared spectra before and after adsorption of the material, it can be known which functional groups participate in the reaction process of the material, whether chemical groups change or not, and the like. As can be seen from FIG. 10, the wave number of the composite biochar material before adsorption is 3383cm ^-1 、1542cm ^-1 、995cm ^-1 、611cm ^-1 All parts have absorption of 3383cm ^-1 Peak at position (2 cm) is the stretching vibration peak of-OH in-COOH ^-1 The peak at the position is an absorption peak corresponding to a benzene ring structure, and the peak is 995cm ^-1 The peak is a C-H out-of-plane bending vibration region, 611cm ^-1 The peak is the stretching vibration peak of Mn-O. The adsorbed composite biochar material is 1542cm ^-1 An absorption peak of an amide structure appears, and the peak corresponds to a bacteriostatic structure beta-lactam ring of the penicillin potassium, which indicates that the composite biochar adsorbs the penicillin potassium.

The XPS characterization analysis is carried out on the composite biochar material before and after the reaction, so that the content and valence of elements related to the adsorption process in the composite biochar can be analyzed, and the related reaction process can be analyzed.

Fig. 11 is XPS total spectrograms before and after adsorption of the composite biochar, and it can be found that the composite biochar mainly contains C, O, Mn before adsorption, while the content of C element in the composite biochar is increased after penicillin potassium is adsorbed, which proves that the composite biochar successfully adsorbs a part of organic substances such as penicillin potassium.

Fig. 12 and 13 are O1s spectra before and after adsorption of the composite biochar, and comparative analysis shows that a peak of an oxide appears in the O1s spectrum after reaction, while zero-valent manganese is also loaded on the composite biochar prepared by the experiment, and the XPS standard spectrum manual analysis is combined, so that the added oxide is probably manganese oxide or a combination of the manganese oxide and penicillin potassium; as for the hydroxide or H-O-C peak, the peak contrast was increased before the adsorption, which is probably because the composite biochar adsorbed a certain amount of penicillin potassium, and the hydroxyl group on the penicillin potassium was loaded on the surface of the composite biochar. After penicillin potassium is adsorbed, the phenomenon that the C-O peak area is obviously reduced is caused, probably because active functional groups on the surface of the adsorbing material are combined with oxygen, and the situation that the composite biochar is easy to chemically adsorb water is caused in the binding energy peak range of 532 eV.

FIGS. 14 and 15 show Mn2p spectra before and after adsorption of the composite biochar, and comparative analysis shows that four

peaks

653, 644, 642.4 and 640.8 appear in the range of 635-660 eV binding energy, and correspond to Mn respectively ⁴⁺ 、Mn ⁴⁺ 、Mn ³⁺ 、Mn ²⁺ And transition peaks. However, Mn did not appear before and after the adsorption ⁰ Probably because the composite biochar is oxidized into bivalent manganese or trivalent manganese in the process of loading zero-valent manganese, and possibly in long-term contact with air in the storage process, the zero-valent manganese on the loading material is oxidized by oxygen in the air.

The present invention has been described in detail above. It will be apparent to those skilled in the art that the invention can be practiced within a wide range of equivalent parameters, concentrations, and conditions without departing from the spirit and scope of the invention and without undue experimentation. While the invention has been described with reference to specific embodiments, it will be appreciated that the invention can be further modified. In general, this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. The use of some of the essential features is possible within the scope of the claims attached below.

Claims

1. The application of the composite biochar to removing the penicillin potassium in the water body is characterized in that the composite biochar and persulfate are added into the water body with the penicillin potassium content of 50mg/L, the adding amount of the composite biochar is 0.5g/L, and the adding amount of the persulfate is 1-40 mmol/L;

the composite biochar is orange peel biochar prepared from orange peel serving as a material by a carbothermic method and loaded with zero-valent manganese, and the specific preparation method of the orange peel biochar comprises the following steps: drying orange peel at 60 ℃, crushing and sieving with a 100-mesh sieve, filling the sieved powder into a ark, heating to 550 ℃ at a heating rate of 6.25 ℃/min in a tubular furnace with an initial temperature of 50 ℃, keeping the temperature for pyrolysis for 2 hours, carrying out nitrogen protection at a ventilation rate of 0.6L/min, and taking out the orange peel biochar material after cooling to room temperature;

the method for loading zero-valent manganese on the orange peel biochar comprises the following steps: adding the orange peel biochar into a manganese sulfate solution, extracting the sodium borohydride solution into the manganese sulfate solution by using a constant flow pump under the condition of stirring, continuing to react, standing and precipitating after extracting the sodium borohydride solution, cleaning the obtained precipitate with oxygen-free water, drying in vacuum, sieving, sealing and storing, and placing in a dryer for later use.

2. The use as claimed in claim 1, wherein the surface of the composite biochar adsorbs potassium penicillin particles, which are aggregated to form agglomerates on the biochar surface.

3. The use as claimed in claim 1, wherein magnesium or calcium ions coexisting in the water body having a potassium penicillin content of 50mg/L have a promoting effect on the removal of potassium penicillin.

4. The use according to claim 3, wherein the content of magnesium ions in the water body is 0.01-0.1 mol/L; the content of the calcium ions in the water body is 0.01-0.1 mol/L.

5. The use according to claim 4, wherein the content of magnesium ions in the water body is 0.1 mol/L; the content of the calcium ions in the water body is 0.1 mol/L.

6. Use according to claim 1, characterized in that the pH of the water body with a potassium penicillin content of 50mg/L is 3-9.

7. Use according to claim 6, wherein the pH of the water body with a potassium penicillin content of 50mg/L is 3 or 9.

8. Use according to claim 1, characterized in that the temperature of the water body with a penicillin potassium content of 50mg/L is 15-35 ℃.

9. The use as claimed in claim 1, wherein the reaction temperature of the composite biochar activated persulfate in the water with the penicillin potassium content of 50mg/L is 35 ℃, the reaction time is 150min, the pH is 3 or 9, the adding amount of the composite biochar is 0.5g/L, the adding amount of the persulfate is 40mmol/L, and the concentration of magnesium or calcium ions is 0.1 mol/L.

10. A method for removing penicillin potassium in a water body is characterized in that composite biochar and persulfate are added into the water body, the composite biochar activates the persulfate to remove penicillin potassium in the water body, the adding amount of the composite biochar is 0.5g/L and the adding amount of the persulfate is 1-40mmol/L in the water body with the penicillin potassium content of 50 mg/L;

the composite biochar is orange peel biochar prepared from orange peel serving as a material by a carbothermic method and loaded with zero-valent manganese, and the specific preparation method of the orange peel biochar comprises the following steps: drying orange peel at 60 ℃, crushing and sieving with a 100-mesh sieve, filling the sieved powder into a ark, heating to 550 ℃ at a heating rate of 6.25 ℃/min in a tubular furnace with an initial temperature of 50 ℃, keeping the temperature for pyrolysis for 2 hours, carrying out nitrogen protection at an air flow of 0.6L/min during the pyrolysis, and taking out an orange peel biochar material after cooling to room temperature;