CN105289470A - Method for preparing charcoal-supported attapulgite nano composite by using antibiotic wastewater - Google Patents

Abstract

The invention discloses a method for preparing an attapulgite nanocomposite material loaded with biochar by utilizing antibiotic waste water, and belongs to the technical field of composite materials. The present invention treats the attapulgite clay with a compound acid to fully decompose the carbonate in the attapulgite clay, further dredges the adsorption pores of the attapulgite, and at the same time endows the surface with functional groups to effectively improve the adsorption of antibiotics performance; then use the attapulgite that adsorbs antibiotics as a carbon source, and after calcination, the micropore and mesoporous structure of attapulgite is activated, and the adsorption of heavy metal ions by attapulgite is significantly improved by loading biochar in situ performance. Therefore, this application not only realizes the treatment of antibiotic wastewater, but also realizes the reuse of organic molecules such as antibiotics, and obtains an adsorbent with excellent adsorption performance, which has broad application prospects in water purification, soil improvement and restoration.

Description

Method for preparing biochar-loaded attapulgite nanocomposites using antibiotic wastewater

technical field

The invention relates to a method for preparing an attapulgite nanocomposite material, in particular to a method for preparing an attapulgite nanocomposite material loaded with biochar by using antibiotic wastewater.

Background technique

Pharmaceutical wastewater is industrial wastewater formed through pharmaceutical production, mainly including four types: industrial wastewater generated in the production of antibiotics, industrial wastewater generated in the production of Chinese patent medicines, industrial wastewater generated in the production of synthetic medicines, and the production process of various pharmaceutical preparations in the wash water. Wastewater has the characteristics of complex composition and high toxicity, and has become one of the sources of wastewater pollution at this stage.

Antibiotic wastewater treatment methods are mainly divided into physical, chemical and biological methods. Among them, the adsorption method in the physical method is widely used in various pharmaceutical wastewater treatment due to its simple operation and wide adaptability. Among the many adsorbents, activated carbon is the most widely used. When the dosage is 30g/L and the adsorption time is 6h, the removal rates of wastewater TOC, COD and chroma can reach 86.99%, 88.43% and 94.08% respectively, and the effluent can reach the Discharge Standard of Fermentation Industrial Wastewater Pollutants ( GB1903—2008) (Wang Jianxing, Wei Yuansong, Cheng Yutao, etc. Advanced treatment of antibiotic wastewater by granular activated carbon［J］. Chinese Journal of Environmental Engineering, 2013, 7(2):401-410.), but the treatment cost of activated carbon is relatively higher.

In recent years, based on green chemistry, the technological revolution of green water treatment has been carried out, and it has become the frontier of wastewater treatment science. For example, CN104828900A discloses a method for photocatalytic reduction treatment of antibiotic wastewater containing nitroimidazole; CN104671579A discloses a method for advanced treatment of antibiotic wastewater using physical and chemical methods, especially involving the combination of electromagnetic technology and Fenton technology in the advanced treatment of antibiotic wastewater Application in; CN104118947A also discloses a method for advanced treatment and reuse of antibiotic wastewater. The method takes the biochemically treated antibiotic wastewater as the treatment object, adopts activated carbon filtration, pH value adjustment, and nanofiltration combined process for advanced treatment, and uses activated carbon filtration to further remove the residual refractory organic matter in the biochemical effluent, and reduce the organic pollution of the nanofiltration membrane. , and then adjust the pH value of the activated carbon effluent to reduce the inorganic pollution of the nanofiltration membrane, and finally use the nanofiltration membrane to effectively remove the remaining organic matter and multivalent ions in the wastewater, and realize the treatment and reuse of antibiotic wastewater, but the operating cost is still relatively high.

Attapulgite is a layer-chain hydrous magnesium-rich aluminosilicate clay mineral with a unique nanofibrous structure. The existence of special channels and active centers of attapulgite makes it widely used in the adsorption of organic molecules. Studies have shown that natural attapulgite clay can effectively remove tetracycline and oxytetracycline in water, with a saturated adsorption capacity of 74.5 mg/g for tetracycline and 69.2 mg/g for oxytetracycline (Guo Na, Wang Jinsheng, Li Jian, et al. Adsorption of two tetracycline antibiotics in attapulgite clay [J]. Environmental Science and Technology, 2015, 38 (3): 81-85.). Therefore, loading antibiotics on attapulgite as a carbon source to prepare adsorption materials not only realizes the reuse of organic molecules such as antibiotics, but also effectively improves the adsorption performance of attapulgite.

Contents of the invention

The purpose of the present invention is to provide a method for preparing biochar-loaded attapulgite nanocomposites by utilizing antibiotic waste water.

1. Preparation of attapulgite nanocomposites

The method for preparing the attapulgite nano-composite material loaded with biochar in the present invention is to treat the attapulgite clay with an acid solution, press filter until the water content is less than 40%, and then send it into a rotary kiln for calcination at 200-500°C for 1-4 hours. Grinding to a particle size of >200 mesh, carrying out adsorption treatment with wastewater containing antibiotics, sending it into a rotary kiln after pressure filtration, and carbonizing at 200-600°C for 1-4 hours under a nitrogen atmosphere, and finally washing, drying, and sieving to obtain Attapulgite nanocomposites loaded with biochar.

Since the natural attapulgite clay is associated with carbonates, moderate acid treatment can decompose carbonates and dredge the adsorption pores of attapulgite to further improve the adsorption performance. For this reason, the present invention endows the surface modification functional group while treating the attapulgite with acid, further improving its adsorption capacity. The acid treatment of the attapulgite clay in the present invention is to add the attapulgite clay to a compound acid solution with a mass percent concentration of 3 to 20% under stirring conditions, and prepare the attapulgite clay with a mass percent concentration of 10 to 20%.

% suspension, react for 1~4h. Wherein, the composite acid solution is composed of sulfuric acid and organic acid (chloroacetic acid, citric acid, glycine or benzoic acid), and the mass ratio of sulfuric acid to organic acid sulfuric acid is 1:4~1:10.

The antibiotic-containing wastewater is wastewater produced during the production process of oxytetracycline, chlortetracycline, tetracycline or penicillin.

The adsorption treatment is a dynamic adsorption method, the solid-liquid ratio is 1:5~1:20kg/L, and the treatment is 4~24h.

Fig. 1 is the TEM photo and partial enlarged view of the attapulgite nanocomposite material loaded with biochar prepared in the present invention. It can be observed that the prepared nanocomposites have a typical rod-like structure of attapulgite, and carbon adheres to the surface of attapulgite to form a rod-shaped composite material with a diameter of about 10-40 nm and a length of about 0.4-1.0 μm. The formation of is conducive to its effective adsorption of heavy metal ions.

2. Adsorption properties of attapulgite nanocomposites

Figure 2 shows the adsorption properties of biochar/attapulgite nanocomposites for Pb(II), Cd(II) and Cu(II) obtained by calcining attapulgite at different temperatures for adsorbing chlortetracycline wastewater. It can be seen from Fig. 2 that with the increase of calcination temperature, the adsorption properties of the obtained nanocomposites to Pb(II), Cd(II) and Cu(II) showed a gradual decrease trend. When the calcination temperature was 200℃, the adsorption capacity of the composite to Pb(II), Cd(II) and Cu(II) reached the maximum, and the maximum adsorption capacity was 56, 30 and 28 mg/g, respectively. The results indicate that this kind of composite material can achieve efficient removal of heavy metal ions.

Figure 3 shows the adsorption properties of biochar/attapulgite nanocomposites to Pb(II), Cd(II) and Cu(II) obtained by calcining attapulgite wastewater with oxytetracycline wastewater at different temperatures. It can be seen from Figure 3 that with the increase of calcination temperature, the adsorption properties of the obtained nanocomposites to Pb(II), Cd(II) and Cu(II) showed a trend of first increasing and then decreasing. When the calcination temperature was 400℃, the adsorption capacity of the composite material to Pb(II), Cd(II) and Cu(II) reached the maximum, and the maximum adsorption capacity was 70, 42 and 39 mg/g, respectively. The results indicate that this kind of composite material can achieve efficient removal of heavy metal ions.

Figure 4 shows the adsorption performance of biochar/attapulgite nanocomposites on Pb(II), Cd(II) and Cu(II) obtained by calcining attapulgite wastewater with tetracycline wastewater at different temperatures. It can be seen from Figure 4 that with the increase of calcination temperature, the adsorption properties of the obtained nanocomposites to Pb(II), Cd(II) and Cu(II) showed a gradual increase trend. When the calcination temperature was 600℃, the adsorption capacity of the composite to Pb(II), Cd(II) and Cu(II) reached the maximum, and the maximum adsorption capacity was 92, 48 and 45 mg/g, respectively. The results indicate that this kind of composite material can achieve efficient removal of heavy metal ions.

Fig. 5 Adsorption performance of biochar/attapulgite nanocomposites for Pb(II), Cd(II) and Cu(II) obtained by calcination of attapulgite from penicillin wastewater at different temperatures. It can be seen from Figure 5 that with the increase of calcination temperature, the adsorption properties of the obtained nanocomposites to Pb(II), Cd(II) and Cu(II) showed a trend of first increasing and then decreasing. When the calcination temperature was 500℃, the adsorption capacity of the composite to Pb(II), Cd(II) and Cu(II) reached the maximum, and the maximum adsorption capacity was 70, 42 and 39 mg/g, respectively. The results indicate that this kind of composite material can achieve efficient removal of heavy metal ions.

In summary, the present invention treats attapulgite clay with compound acid to fully decompose the carbonate in attapulgite clay, further dredge the adsorption pores of attapulgite, and at the same time endow the surface with functional groups, effectively improving the Its adsorption performance on antibiotics; then using the attapulgite that adsorbs antibiotics as a carbon source, the micropore and mesopore structure of attapulgite was activated after calcination, and the attapulgite was significantly improved by in-situ loading of biochar. Adsorption properties for heavy metal ions. Therefore, this application not only realizes the treatment of antibiotic wastewater, but also realizes the reuse of organic molecules such as antibiotics, and obtains an adsorbent with excellent adsorption performance, which has broad application prospects in water purification, soil improvement and restoration.

Description of drawings

In Fig. 1 (a) TEM photo of biochar/attapulgite nanocomposites after carbonization of attapulgite with chlortetracycline wastewater at 200°C; (b) partially enlarged biochar/attapulgite nanocomposites after carbonization at 200°C TEM photo of the composite material.

Fig. 2 Adsorption properties of biochar/attapulgite nanocomposites for Pb(II), Cd(II) and Cu(II) obtained by calcination of attapulgite from chlortetracycline wastewater at different temperatures.

Fig. 3 Adsorption properties of biochar/attapulgite nanocomposites for Pb(II), Cd(II) and Cu(II) obtained by calcination of attapulgite wastewater at different temperatures for adsorption of oxytetracycline wastewater.

Fig. 4 Adsorption performance of biochar/attapulgite nanocomposites for Pb(II), Cd(II) and Cu(II) obtained by calcination of attapulgite wastewater with tetracycline wastewater at different temperatures.

Fig. 5 Adsorption performance of biochar/attapulgite nanocomposites for Pb(II), Cd(II) and Cu(II) obtained by calcination of attapulgite from penicillin wastewater at different temperatures.

detailed description

The preparation of the biochar-loaded attapulgite nanocomposite material of the present invention will be further described through specific examples below.

Example 1

Under the condition of stirring at 200 rpm, 100kg of attapulgite clay was added to 1000L of a mixed solution of sulfuric acid and chloroacetic acid (the mass concentration of sulfuric acid was 0.6%, and the mass concentration of chloroacetic acid was 2.4%), stirred for 4 hours, and passed through a filter press. After pressure filtration, it is sent to a rotary kiln for calcination at 400°C for 2 hours, crushed, and treated with aureomycin-containing wastewater by dynamic adsorption for 24 hours (solid-to-liquid ratio is 1:10kg/L). , calcined and carbonized at 200°C for 1 h, and finally washed, dried, and sieved to obtain attapulgite nanocomposites loaded with biochar. The adsorption capacities of the composite for Pb(II), Cd(II) and Cu(II) were 56, 30 and 28 mg/g, respectively.

Example 2

Under the stirring condition of 200 rpm, add 150kg of attapulgite clay into 1000L of the mixed solution of sulfuric acid and glycine (the mass concentration of sulfuric acid is 2%, the mass concentration of glycine is 8%), stir for 2 hours, and filter through the filter press After that, it is sent to the rotary kiln for calcination at 200°C for 1 hour, crushed, treated with oxytetracycline-containing wastewater by dynamic adsorption method for 12 hours (solid-liquid ratio is 1:15kg/L), and sent to the rotary kiln after pressure filtration, nitrogen atmosphere, 400 ℃ calcination and carbonization for 2 hours, and finally washed, dried, and sieved to obtain the attapulgite nanocomposite material loaded with biochar. The adsorption capacities of the composite for Pb(II), Cd(II) and Cu(II) were 70, 42 and 39 mg/g, respectively.

Example 3

Under the condition of stirring at 200 rpm, 200kg of attapulgite clay was added to 1000L of the mixed solution of sulfuric acid and glycine (the mass concentration of sulfuric acid was 4%, and the mass concentration of citric acid was 16%), stirred for 3 hours, and pressed by a filter press. After filtration, it is sent to the rotary kiln, calcined at 500°C for 2 hours, and after crushing, it is treated with wastewater containing tetracycline for 24 hours by dynamic adsorption method (solid-to-liquid ratio is 1:5kg/L), and then sent to the rotary kiln after pressure filtration. Roasting and carbonizing at 600°C for 4 hours, and finally washing, drying, and sieving to obtain the attapulgite nanocomposite material loaded with biochar. The adsorption capacities of the composite for Pb(II), Cd(II) and Cu(II) were 92, 48 and 45 mg/g, respectively.

Example 4

Under the condition of stirring at 200 rpm, 120kg of attapulgite clay was added to 1000L of a mixed solution of sulfuric acid and benzoic acid (the mass concentration of sulfuric acid was 2%, and the mass concentration of benzoic acid was 8%), stirred for 4 hours, and passed through a filter press. After pressure filtration, it is sent to a rotary kiln for calcination at 400°C for 4 hours, crushed, and then treated with penicillin-containing wastewater by dynamic adsorption for 12 hours (solid-liquid ratio is 1:10kg/L). After pressure filtration, it is sent to a rotary kiln under nitrogen atmosphere , roasted and carbonized at 500°C for 3h, and finally washed, dried, and sieved to obtain the attapulgite nanocomposite material loaded with biochar. The adsorption capacities of the composite for Pb(II), Cd(II) and Cu(II) were 79, 51 and 48 mg/g, respectively.

Claims (8)

1. A method for preparing biochar-loaded attapulgite nanocomposites using antibiotic wastewater, characterized in that: the attapulgite clay is treated with an acid solution, press-filtered and then calcined at 200-500°C for 1-4h, pulverized, and used Antibiotic wastewater is treated by adsorption, press-filtered and sent to a rotary kiln, carbonized at 200-600°C for 1-4 hours under a nitrogen atmosphere, and finally washed, dried, and sieved to obtain attapulgite nanocomposites loaded with biochar . 2. utilize antibiotic waste water to prepare the method for the attapulgite nanocomposite material of loading biochar as claimed in claim 1, it is characterized in that: the acid treatment of attapulgite clay is under stirring condition, attapulgite clay is added to In the compound acid solution with a concentration of 3-20% by mass, prepare a suspension with a concentration of 10-20% by mass, and react for 1-4 hours. 3. utilize antibiotic waste water to prepare the method for the attapulgite nano-composite of loaded biochar as claimed in claim 2, it is characterized in that: described compound acid solution is compounded by sulfuric acid and organic acid, and the mass ratio of sulfuric acid and organic acid sulfuric acid 1:4~1:10. 4. The method for preparing biochar-loaded attapulgite nanocomposites using antibiotic waste water as claimed in claim 3, wherein the organic acid is one of chloroacetic acid, citric acid, glycine, and benzoic acid. 5. The method for preparing biochar-loaded attapulgite nanocomposites using antibiotic wastewater according to any one of claims 1 to 4, characterized in that: the attapulgite clay is treated with an acid solution and then press-filtered to a water content of <40% . 6. The method for preparing biochar-loaded attapulgite nanocomposites using antibiotic waste water according to any one of claims 1 to 4, characterized in that: the attapulgite clay is press-filtered and calcined and crushed to a particle size > 200 head. 7. as described in claim 1～4, any method utilizing antibiotic waste water to prepare the attapulgite nano-composite material loaded with biochar, is characterized in that: described antibiotic waste water is oxytetracycline, chlortetracycline, tetracycline or penicillin waste water from the production process. 8. as described in any one of claim 1～4, utilize antibiotic waste water to prepare the method for the attapulgite nano-composite material loaded with biochar, it is characterized in that: described adsorption treatment adopts dynamic adsorption method, and solid-liquid ratio is 1:5 ~1:20kg/L, treatment 4~24h.