NL2030657B1

NL2030657B1 - Adsorbent, preparation method and application thereof

Info

Publication number: NL2030657B1
Application number: NL2030657A
Authority: NL
Inventors: Wang Yulong; Lu Na; Liu Rui; Bian Ce; Sheng Ya; Li Wei; Li Tao; Gao Wei; Liu Yanfang; Li Zaixing; Shi Linsong
Original assignee: Qiaoxi Sewage Treat Plant Of Shijiazhuang Sewage Treat Co Ltd; Univ Hebei Science & Tech
Priority date: 2021-09-16
Filing date: 2022-01-23
Publication date: 2023-09-06
Also published as: CN113731363A; NL2030657A

Abstract

Disclosed is an adsorbent, a preparation method and application thereof, and belongs to the technical field of environmental adsorption materials. The adsorbent is obtained by loading iron and zirconium on biochar; the biochar is biochar prepared from antibiotic residue. The main raw material of the adsorbent prepared by the invention is antibiotic residue, which realizes the recycling of waste biomass. The adsorbent prepared by the invention has high phosphorus removal efficiency, good removal effect on sewage with different phosphorus concentrations, and can effectively alleviate eutrophication of water bodies. The method of the invention is simple and feasible, potassium carbonate activation and hydrochloric acid pickling are adopted, the specific surface area of biochar is greatly increased, and its adsorption capacity is enhanced; and the biochar prepared from antibiotic bacterial residue is modified by loading iron and zirconium by coprecipitation method, so that the phosphorus removal capacity of adsorbent is greatly improved.

Description

Adsorbent, preparation method and application thereof

TECHNICAL FIELD

The invention relates to the technical field of environmental adsorption materials, in particular to an adsorbent, a preparation method and application thereof.

BACKGROUND

The excessive discharge of phosphorus is an important cause of eutrophication. How to effectively remove phosphorus from sewage is the key to the treatment of eutrophic water.

Adsorption is an environmentally friendly, economical and efficient technology, which uses solid materials with high specific surface area and pore structure to remove phosphate from water by physical adsorption or chemical adsorption, and the key of phosphorus removal by adsorption is the preparation of adsorption materials.

Biochar is a kind of carbon - rich material, which is produced by heat treatment of different types of biomass under anaerobic or anoxic conditions. Biochar has unique properties, such as high specific surface area, high porosity, stable carbon structure, abundant oxygen - containing functional groups, etc., and is often used as adsorbent in sewage treatment. Generally, the surface of biochar is negatively charged, and its adsorption capacity for anions is poor, which leads to its poor adsorption capacity for phosphorus in sewage.

Antibiotic residue is the waste residue produced in the process of antibiotic production. In the process of antibiotic fermentation, microbial reproduction and metabolism not only produce medicinal antibiotics, but also form a large number of mycelium and a small amount of unused culture medium. After the antibiotic fermentation broth is filtered, the two together constitute antibiotic residue. At present, there is no good disposal method for antibiotic residues. If the antibiotic residue can be used to remove phosphorus from sewage, on the one hand, sewage can be treated, on the other hand, the waste of antibiotic residue can be reused, which will be of great significance to the reuse of antibiotic residue and the field of environmental adsorption materials.

SUMMARY

The purpose of the present invention is to provide an adsorbent, its preparation method and application, in order to solve the above - mentioned problems in the prior art, improve the adsorption capacity of biochar to phosphorus in sewage, and at the same time, recycle the waste biomass with penicillin residue.

To achieve the above objective, the present invention provides the following schemes:

One of the technical solutions of the invention is an adsorbent, which is obtained by loading iron and zirconium on biochar;

The total load of iron and zirconium in that adsorbent is not less than 15wt%;

the biochar is biochar prepared from antibiotic residue.

In the second technical scheme of the invention, the preparation method of the adsorbent comprises the following steps: step 1, crushing antibiotic residue dried to constant weight, adding it into water with an activator in a mass ratio of 1: 1, mixing evenly, centrifuging, and drying the separated solid part to obtain preactivated antibiotic residue; activator can increase the specific surface area of biochar; step 2, pyrolyzing the preactivated antibiotic residue to obtain biochar; step 3, pickling the biochar, centrifuging and washing to neutrality to obtain active biochar; pickling can further increase the specific surface area of biochar; step 4, adding the active biochar into the mixed aqueous solution of zirconium oxychloride and ferric chloride and stirring, then adjusting the pH value to 10 - 12, stirring, aging, filtering, washing to neutrality and drying to obtain the adsorbent.

Zirconium has a good adsorption effect on phosphorus in sewage, and loading zirconium on the surface of biochar can increase the adsorption effect of biochar on phosphorus.

Appropriate amount of iron can make zirconium oxide form finer structure, increase the specific surface area of adsorbent, make its surface have more adsorption sites, and enhance its adsorption effect on phosphorus. At the same time, iron itself has a certain affinity for phosphorus, which can further improve the adsorption effect of adsorbent on phosphorus.

Further, in step 1, the activator is potassium carbonate.

Further, in step 1, the drying temperature is 100 - 110°C.

Further, in step 2, the pyrolysis specifically includes heating to 600 - 700°C at a speed of 5 - 10°C/min under the protection of nitrogen, and keeping the temperature for 1 - 2h.

Further, the acid in step 3 is hydrochloric acid.

Furthermore, in step 4, the molar ratio of zirconium and iron ions in the mixed aqueous solution of zirconium oxychloride and ferric chloride is 7: 3, and the sum of the concentrations of zirconium and iron ions is 0.1 - G.3mol/l.

Further, in step 4, the adjusted pH value is adjusted by NaOH solution.

Further, in step 4, the drying temperature is 100 - 110°C.

The third technical scheme of the invention is the application of the adsorbent in phosphorus - containing sewage treatment.

The invention discloses the following technical effects:

The main raw material of the adsorbent prepared by the invention is antibiotic residue, which realizes the recycling of waste biomass. The adsorbent prepared by the invention has high phosphorus removal efficiency, good removal effect on sewage with different phosphorus concentrations, and can effectively alleviate eutrophication of water bodies.

The method of the invention is simple and feasible, potassium carbonate activation and hydrochloric acid pickling are adopted, the specific surface area of biochar is greatly increased,

and its adsorption capacity is enhanced; and the biochar prepared from antibiotic bacterial residue is modified by loading iron and zirconium by coprecipitation method, so that the phosphorus removal capacity of adsorbent is greatly improved.

The adsorbent prepared by the invention can be used as a soil improver to increase the phosphorus content in the soil after phosphorus adsorption saturation, and at the same time, the biochar can improve the soil compaction, activate the soil and improve the soil quality.

BRIEF DESCRIPTION OF THE FIGURES

In order to more clearly explain the examples of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings needed in the examples. Obviously, the drawings in the following description are only some examples of the present invention, and for ordinary technicians in the field, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a process flow chart for preparing adsorbent according to the present invention;

Fig. 2 is a SEM image of the adsorbent prepared in Example 1;

Fig. 3 is an EDS chart of the adsorbent prepared in Example 1;

Fig. 4 is the desorption pore size distribution diagram of activated biochar prepared in step 3 of Example 1;

Fig. 5 is the desorption pore size distribution diagram of the adsorbent prepared in Example 1.

DESCRIPTION OF THE INVENTION

Now, various exemplary examples of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of some aspects, characteristics and examples of the present invention.

It should be understood that the terms used in this invention are only for describing specific examples, and are not used to limit the invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Any stated value or intermediate value within the stated range and any other stated value or every smaller range between intermediate values within the stated range are also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by the ordinary technicians in the field of this invention.

Although the present invention only describes the preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and/or materials related to the documents. In case of conflict with any incorporated documents, the contents of this specification shall prevail.

Without departing from the scope or spirit of the present invention, it is obvious to those skilled in the art that many modifications and changes can be made to the specific examples of the present invention. Other examples obtained from the description of the present invention will be obvious to the skilled person. The description and example of that present invention are exemplary only.

The words "comprising", "including", "having" and "containing" used in this paper are all open terms, that is, they mean including but not limited to.

The antibiotic residue used in the example of the invention is specifically penicillin residue.

The process flow adopted by the example of the invention is shown in Figure 1.

Example 1

Step 1, drying penicillin residue to constant weight, crushing and grinding, passing through a 60 - mesh sieve, and collecting for later use; adding dried penicillin residue and potassium carbonate into deionized water at a mass ratio of 1 : 1 to obtain a mixture, wherein the amount of deionized water is 5 times that of penicillin residue, placing the mixture on a magnetic stirrer and stirring for 2 hours at a rotating speed of 1000 rpm, centrifuging in a centrifugal tube after stirring to obtain a solid part, and drying the solid part in a 110°C oven to obtain preactivated penicillin residue; step 2, placing the preactivated penicillin residue in a tube furnace, raising the temperature from room temperature to 600°C at a speed of 10°C/min under the protection of nitrogen, and keeping the temperature for 2 hours for anaerobic pyrolysis to obtain biochar; step 3, soaking the biochar prepared in step 2 in 3 mol/l hydrochloric acid for 10 min, centrifuging, cleaning with deionized water to be neutral, and drying and preserving at 110°C to obtain active biochar; step 4, zirconium oxychloride and ferric chloride are added into 200ml deionized water with the molar ratio of zirconium and iron ions of 7 : 3 and the total molar concentration of 0.1 mol/l.

After fully mixing, 2 g of activated biochar is added, and stirred for 1 hour on a magnetic stirrer with the rotating speed of 1000 rpm, then 1 mol/l NaOH solution is gradually added dropwise to adjust the pH to 10, and the stirring is continued for 1 hour. After stopping stirring, standing for 30 min, filtering, repeatedly washing with deionized water until the supernatant is neutral, and then drying in an oven at 110°C to obtain iron - zirconium - loaded biochar, that is, adsorbent.

The method of measuring the phosphorus adsorption capacity of the adsorbent prepared in this example is as follows: weighing 0.1 g adsorbent and 40 ml of 100 mg/l KH2PO: solution,

oscillating and adsorbing in a centrifugal tube at 25°C and 200 rpm for 24 h, and measuring the phosphorus adsorption capacity of the adsorption material.

After testing, the phosphorus adsorption capacity of the adsorbent prepared in this example was 16.77 mg/g under the above conditions. 5 The average pore diameter of the adsorbent prepared in this example is 1.9286 nm, the specific surface area is 695.8994 m?/g, the loading of iron in the adsorbent is 8.3 wt. %, and the loading of zirconium is 9.1 wt. %.

The SEM image of the adsorbent prepared in this example is shown in Figure 2. From

Figure 2, it can be seen that the adsorbent has rich pore structure, rough surface and small particles attached, which indicates that iron zirconium oxide has been successfully loaded on the surface of biochar, and a large number of adsorption sites are provided for the adsorbent.

The EDS chart of the adsorbent prepared in this example is shown in fig. 3, and it can be seen from fig. 3 that iron and zirconium are successfully loaded on the surface of biochar, in which the loading amount of zirconium is 9.1 wt.% and the loading amount of iron is 8.3 wt.%.

The desorption pore size distribution diagram of the active biochar prepared in step 3 of this example obtained by BJH method is shown in Figure 4. From Figure 4, it can be seen that the pore size distribution of the active biochar is mainly micropores, concentrated between 1 - 2nm, belonging to microporous biochar, and the average pore size of the mesoporous part is about 4nm. It shows that the active biochar can be used as an excellent carrier.

The desorption pore size distribution diagram of the adsorbent prepared in this example obtained by BJH method is shown in Figure 5. From Figure 5, it can be seen that the average pore size of the adsorbent loaded with iron and zirconium is slightly increased compared with that of the active biochar prepared in step 3, but it is still mainly concentrated in the range of 1 — 2 nm, which belongs to microporous biochar. The average pore size of mesoporous part is about 3 nm. The pore size distribution of the adsorbent makes the adsorbent have a large number of adsorption sites and strong phosphorus adsorption capacity.

Example 2

Same as Example 1 except that the pyrolysis time in step 2 is 1 h.

The phosphorus adsorption capacity of the adsorbent prepared in this example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent prepared in this example is 13.37 mg/g. The average pore diameter of the adsorbent is 1.6432 nm, the specific surface area is 612.3566 m?/g, and the loading of iron and zirconium in the adsorbent is 7.9 wt.% and 8.4 wt.%, respectively.

Example 3

Same as Example 1, except that the pyrolysis temperature in step 2 is 700°C and the time is 1h.

The phosphorus adsorption capacity of the adsorbent prepared in this example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent prepared in this example was 9.81 mg/g. The average pore diameter of the adsorbent is 1.5782 nm, the specific surface area is 565.4753 m?/g, and the loading of iron and zirconium in the adsorbent is 7.5 wt.% and 7.7 wt.%, respectively.

Example 4

Same as Example 1, except that the pyrolysis temperature in step 2 is 700°C.

The phosphorus adsorption capacity of the adsorbent prepared in this example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent prepared in this example is 12.53 mg/g. The average pore diameter of the adsorbent is 1.6138 nm, the specific surface area is 642.6349 m?/g, and the loading of iron and zirconium in the adsorbent is 7.3 wt.% and 7.9 wt.% respectively.

Example 5

Same as Example 1, except that the drying temperature in step 1 is 100°C, the heating rate in step 2 is 5°C/min, the total molar concentration of zirconium and iron ions in step 4 is 0.2 mol/l, the pH value is 11, and the drying temperature is 100°C.

The method of measuring the phosphorus adsorption capacity of the adsorbent prepared in this example is as follows: weighing 0.1 g adsorbent and 40 ml of 80 mg/l KH2PO, solution, shaking and adsorbing in a centrifugal tube at 25°C and 170 rpm for 24 h, and measuring the phosphorus adsorption capacity of the adsorption material.

After testing, the phosphorus adsorption capacity of the adsorbent prepared in this example is 12.53 mg/g. The average pore diameter of the adsorbent is 1.4528nm, the specific surface area is 593.5482 m?/g, and the loading of iron and zirconium in the adsorbent is 8.9 wt.% and 9.4 wt.% respectively.

Example 6

Same as Example 1, except that the drying temperature in step 1 is 105°C, the heating rate instep 2 is 8°C/min, the total molar concentration of zirconium and iron ions in step 4 is 0.3 mol/l, the pH value is 12, and the drying temperature is 105°C.

The phosphorus adsorption capacity of the adsorbent prepared in this example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent prepared in this example was 9.41 mg/g. The average pore diameter ofthe adsorbent is 1.4387 nm, the specific surface area is 503.5315 m?/g, and the loading of iron and zirconium in the adsorbent is 9.1wt% and 9.3 wt% respectively.

Comparative example 1

Same as Example 1 except that no ferric chloride is added in step 4.

The phosphorus adsorption capacity of the adsorbent prepared in this comparative example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent prepared in this comparative example is 8.28 mg/g. The average pore diameter of the adsorbent is 1.7693 nm, the specific surface area is 732.1855 m?/g, and the loading of zirconium is 10.4 wt.%.

Comparative example 2

Same as Example 1, only the difference is that penicillin residue is replaced by Artemia cysts egg shell.

The method of measuring the phosphorus adsorption capacity of the adsorbent prepared in this comparative example is as follows: weighing 0.1 g adsorbent and 100 ml KH2PO4s solution with a phosphorus concentration of 500 mg/l, oscillating and adsorbing for 24 h in a centrifugal tube at 25°C and 170 rpm, and measuring the phosphorus adsorption capacity of the adsorption material.

After testing, the phosphorus adsorption capacity of the adsorbent of this comparative example is 427 mg/g.

The phosphorus adsorption capacity of the adsorbent prepared in this comparative example is significantly better than that of Examples 1 - 4, which may be caused by the material composition and structural characteristics of Artemia egg shell itself.

Comparative example 3

The adsorbent is commercially available activated carbon with a pore density of 150 holes/square inch, an air velocity of 0.8 m/s in the empty tower and a specific surface area of about 700 square grams.

The phosphorus adsorption capacity of the adsorbent of this comparative example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent of this comparative example is 7.64 mg/g.

The phosphorus adsorption capacity of the adsorbent prepared by the invention is significantly better than that of commercially available activated carbon, which shows that the adsorbent prepared by the invention can be used for sewage treatment, and provides a new direction for the application of antibiotic residues.

Comparative example 4

Same as Example 1, except that the total molar concentration of zirconium and iron ions in step 4 is 0.05 mol/l.

The phosphorus adsorption capacity of the adsorbent prepared in this comparative example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent prepared in this comparative example is 7.12 mg/g. The average pore diameter of the adsorbent is 1.8446 nm, the specific surface area is 768.1291 m?g, the loading of iron in the adsorbent is 6.3 wt.%, and the loading of zirconium is 5.4 wt.%.

Comparative example 5

Same as Example 1, except that the total molar concentration of zirconium and iron ions in step 4 is 0.4 mol/l.

The phosphorus adsorption capacity of the adsorbent prepared in this comparative example was measured by the same method as in Example 1. After testing, the phosphorus adsorption capacity of the adsorbent prepared in this comparative example is 9.19 mg/g. The average pore size of the adsorbent is 1.6411 nm, the specific surface area is 539.9371 mg, the loading of iron in the adsorbent is 10.1 wt.%, and the loading of zirconium is 9.8 wt.%.

The above - mentioned examples only describe the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, all kinds of modifications and improvements made by ordinary technicians in the field to the technical scheme of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

CONCLUSIONS

1. Adsorbent obtained by loading iron and zirconium onto biological charcoal, where the total content of iron and zirconium in the adsorbent is not less than 15% by weight, and the biological charcoal is prepared from antibiotic production waste.

A method for preparing the adsorbent according to claim 1, which method comprises the following steps: step 1: grinding antibiotic production waste dried to constant weight, adding it to water with an activator in a mass ratio of 1: 1 , evenly mixing, centrifuging, and drying the separated solid part to obtain preactivated antibiotic production waste; step 2: pyrolyzing the pre-activated antibiotic production waste to obtain biological charcoal; step 3: acidifying the organic charcoal, centrifuging and washing until neutrality to obtain active organic charcoal; step 4: adding the active organic charcoal to a mixed aqueous solution of zirconium oxychloride and ferric chloride and stirring, then adjusting the pH value to 10 - 12, stirring, allowing to stand, filtering, washing until neutrality and drying to obtain the adsorbent.

The method for preparing the adsorbent according to claim 2, wherein in step 1 the activator is potassium carbonate.

The method for preparing the adsorbent according to claim 2, wherein in step 1 the drying temperature is 100 - 110°C.

The method for preparing the adsorbent according to claim 2, wherein in step 2 the pyrolysis involves heating to 600 - 700°C at a rate of 5 - 10°C/min and maintaining the temperature for 1 - 2 hours under nitrogen protection.

The method for preparing the adsorbent according to claim 2, wherein the acid in step 3 is hydrochloric acid.

The method for preparing the adsorbent according to claim 2, wherein the molar ratio of zirconium and iron ions in the mixed aqueous solution of zirconium oxychloride and iron chloride in step 4 is 7:3, and the sum of the concentrations of zirconium - and iron ions is 0.1 - 0.3 mol/l.

The method for preparing the adsorbent according to claim 2, wherein in step 4 the pH value is adjusted with a NaOH - solution.

The method for preparing the adsorbent according to claim 2, wherein in step 4 the drying temperature is 100 - 110°C.

10. Use of the adsorbent according to claim 1 in the treatment of phosphorus-containing sewage water.