CN113274972A - Composite modified diatomite and preparation method and application thereof - Google Patents
Composite modified diatomite and preparation method and application thereof Download PDFInfo
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Abstract
The invention discloses a composite modified diatomite and a preparation method and application thereof, and the preparation method comprises the following steps: under the acidic condition, mixed bacteria mainly comprising thiobacillus ferrooxidans are used as biocatalyst, and industrial FeSO is used4·7H2Taking O as a raw material and reticular polyurethane as a carrier, and preparing BPFS by adopting a microbial immobilization technology; s2, roasting a proper amount of diatom at the temperature of 1 hour; weighing 2g of the obtained diatomite in an erlenmeyer flask, adding a certain amount of 80g/L of diatomite, soaking in dilute hydrochloric acid for 24 hours, washing to be neutral, drying in an oven at 105 ℃, adding 50mL of demineralized water at 450BPFS, stirring for a period of time at the rotation speed of 300r/min, performing suction filtration to be neutral, and drying a filter cake to obtain the diatomite filter cakeComposite BPFS-DE adsorbent. The BPFS-DE of the invention has larger porosity and larger specific surface area, and has higher adsorption performance on ACBK dye wastewater.
Description
Technical Field
The invention relates to the technical field of water treatment, and particularly relates to composite modified diatomite and a preparation method and application thereof.
Background
With the reduction of fresh water resources and people's concerns about ecosystem and human health, water pollution has always been the subject of attention by today's scholars. Especially, a large amount of artificially synthesized dyes are used in the industries of printing, dyeing and weaving, papermaking, leather, plastics and the like, and the discharged industrial wastewater becomes one of the industrial wastewater which is difficult to treat at home and abroad due to the characteristics of large water quantity, complex components, high toxicity and the like. Therefore, effective disposal and reuse thereof is a key to the development of cleanliness. At present, the dye-containing wastewater is treated by physical, chemical and biological methods, wherein the adsorption method is the most effective method for treating wastewater containing various pollutants due to the advantages of simple preparation, high efficiency, low consumption, environmental friendliness and the like. The adsorbents developed in recent years have metal organic frameworks (MOFs, activated carbon, carbon fiber, etc.), but have disadvantages such as high cost and poor adsorption effect.
Diatomaceous Earth (DE) is a biological siliceous sedimentary rock formed by diagenesis of the shell walls of diatoms (a unicellular lower plant) and other micro-organisms. The main component is amorphous SiO2The composite material has the characteristics of low cost, porosity, large specific surface area, good chemical stability and the like. The application of DE in dye wastewater treatment is rapidly developed. Erdem and other researches find that the maximum adsorption removal rate of the diatomite to the yellow ink 5GF (IY) reaches 99.23%, and the results of the Langmuir and Freundich isothermal model fitting adsorption process show that the natural diatomite has great adsorption potential to high-concentration dye wastewater. A gazette[15]The kieselguhr is adopted to adsorb the methylene blue, and the adsorption capacity can reach 14 mg/g. Researches such as Bibo and the like find that the natural diatomite presents electronegativity due to loss of hydrogen of silicon hydroxyl on the surface of the diatomite under the condition of higher pH value, so that the special charge dye-methylene blue can be conveniently adsorbed. The diatomite wall shell is coated with a mixture of natural diatomiteThe clay, mineral and other impurities of the cover seriously affect the porous performance of the diatomite and limit the application effect of the diatomite.
Disclosure of Invention
In order to solve the problems, the invention provides composite modified diatomite and a preparation method and application thereof.
In order to achieve the purpose, the invention adopts the technical scheme that:
a composite modified diatomite is prepared by compounding Diatomite (DE) and Biological Polymeric Ferric Sulfate (BPFS).
The invention also provides a preparation method of the composite modified diatomite, which comprises the following steps:
s1, under acidic condition, using mixed bacteria mainly containing thiobacillus ferrooxidans as biocatalyst and industrial FeSO4·7H2Taking O as a raw material and reticular polyurethane as a carrier, and preparing BPFS by adopting a microbial immobilization technology;
s2, soaking a proper amount of Diatomite (DE) in dilute hydrochloric acid for 24 hours, washing to be neutral, drying in an oven at 105 ℃, and roasting at 450 ℃ for 1 hour for later use;
s3, weighing 2g of the Diatomite (DE) obtained in the step S2 into a conical flask, adding a certain amount of 80g/L BPFS, adding 50mL of demineralized water, stirring for a period of time at the rotation speed of 300r/min, performing suction filtration to neutrality, and drying a filter cake to obtain the composite BPFS-DE adsorbent.
Further, in step S3, BPFS was added in an amount of 0.09mL for a stirring period of 100 min.
The composite modified diatomite can be used for treating Acid Chrome Blue K (ACBK) dye wastewater; the removal rate of 2mg/L ACBK dye reaches 98.6 percent under the conditions that the adding amount of the composite BPFS-DE adsorbent is 14g/L, the pH value is 6, the temperature is 30 ℃ and the oscillation time is 20 min.
According to the invention, Biological Polymeric Ferric Sulfate (BPFS) is adopted to modify Diatomite (DE) to prepare the high-efficiency composite adsorbent BPFS-DE, the porosity of the BPFS-DE is increased, the specific surface area is increased, the high adsorption performance on ACBK dye wastewater is achieved, and the removal rate of 2mg/L of ACBK dye reaches 98.6% under the conditions that the addition amount of the BPFS-DE is 14g/L, the pH value is 6, the temperature is 30 ℃ and the oscillation time is 20 min.
Drawings
FIG. 1 illustrates the preparation of an adsorbent material.
FIG. 2 shows the adsorption of ACBK by composite adsorbent BPFS-DE.
FIG. 3 is an SEM photograph of purified DE (A) and BPFS-DE (B).
FIG. 4 is a graph showing adsorption and desorption curves of purified DE and BPFS-DE.
FIG. 5 is an XRD spectrum of purified DE and BPFS-DE.
FIG. 6 shows the effect of different reaction conditions on the adsorption effect.
FIG. 7 is an adsorption first order kinetics equation.
FIG. 8 is an adsorption pseudo-second order kinetic equation.
FIG. 9 is a Langmuir isotherm of BPFS-DE.
FIG. 10 is a Freundlich isotherm for BPFS-DE.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
Experimental data:
experimental reagent: diatomaceous earth, concentrated hydrochloric acid, sodium hydroxide, acidic chrome blue K, analytically pure, FeSO4·7H2O, industrial products, tianjin, chemical reagents manufacturing ltd.
An experimental instrument: Q/TBCR2 ultraviolet-visible spectrophotometer, Shanghai Xinmao instruments Inc.; precision pH meter, Shanghai precision scientific instruments, Inc.; SX2-1.8-12 box resistance heating furnace, harbin minister for Yan Heat treatment Equipment manufacturing company; GZX-9070 MBE electric heating air blast drying box, medical equipment of Shanghai Boxun industry Co., Ltd; x-ray diffractometer model D/MAX-1200, Rigaku Denki, Japan; XL30ESM-FEG type field emission Environment scanning Electron microscope, FEL corporation, Netherlands; JS94H Zata potential tester, Shanghai Zhongchen digital technology equipment Co., Ltd; TriStar-3020 specific surface area and pore size Analyzer, Mimorrey instruments, Inc.
Preparation and characterization of the adsorption material: under the acidic condition, mixed bacteria mainly comprising thiobacillus ferrooxidans are used as biocatalyst, and industrial FeSO is used4·7H2Taking O as a raw material and reticular polyurethane as a carrier, and adopting a microbial immobilization technology to prepare the BPFS.
Soaking appropriate amount of DE in dilute hydrochloric acid for 24 hr, washing the soaked DE to neutrality, and oven drying at 105 deg.C in an oven. The dried DE was calcined at 450 ℃ for 1 hour for use. Weighing 2g of purified DE in a conical flask, adding a certain amount of BPFS (80 g/L), adding 50mL of demineralized water, stirring for a period of time at the rotation speed of 300r/min, performing suction filtration to neutrality, and drying a filter cake to obtain the composite BPFS-DE adsorbent. And observing the microscopic morphology and structure of the sample by adopting a scanning electron microscope and a specific surface area agent aperture analyzer.
Adsorption of BPFS-DE on ACBK dye wastewater: weighing 2mg of ACBK, dissolving in deionized water, stirring with a glass rod until the ACBK is dissolved, fixing the volume to 1L, preparing a solution with the concentration of 2mg/L, weighing a certain amount of BPFS-DE, placing in the prepared dye solution, stirring at the rotating speed of 300r/min, sampling after a period of reaction time, measuring the absorbance at the maximum absorption wavelength (lambda =520 nm) with an ultraviolet spectrophotometer, and calculating the dye concentration and the removal rate. The optimum reaction conditions of the adsorbent were tested by varying the amount of adsorbent used, the reaction temperature, the dye concentration and the solution pH. The indexes for determining the optimum experimental conditions are mainly the removal rate and the adsorption amount of ACBK. The calculation formula is as follows: the unit adsorption amount is calculated by the following formula: Q＝（C i -C f ）V/M (ii) a The removal rate calculation formula is as follows: Y=（C i -C f ）/ C f x 100%, in the formula,Qas ACBK adsorption capacity (mg/g);C i the initial concentration (mg/L) of ACBK;C f the concentration of ACBK in the solution after the reaction (mg/L);Mthe dosage (g) of the adsorbent;Vvolume of solution (L);Ythe removal rate is shown.
Results and discussion
Adsorption of BPFS-DE adsorbent prepared under different conditions on ACBK
Different adsorbing materials BPFS-DE are prepared for the adsorption treatment of ACBK dye wastewater by changing the dosage, stirring time, temperature and solution pH value of BPFS in the composite adsorbent, and the result is shown in figure 2. Wherein the dosage of BPFS-DE is 1.0000g, the temperature is 20 ℃, the pH value of the solution is 6.0, and the oscillation time is 30 min.
As shown in FIG. 2(A), the unit adsorption amount and the dye removal rate both increased and then decreased with the increase in the volume of BPFS. When the addition amount of BPFS is 0.09mL, the maximum values of the unit adsorption amount and the dye removal rate are respectively 0.116mg/g and 47.8%, and the adsorption effect is best. The reason may be that when BPFS is added, the zeta potential on the surface of DE particles is reduced, and the repulsive force between BPFS and DE particles is reduced, which is beneficial to the occurrence of adsorption reaction; with the increase of the addition amount of the BPFS, the surface potential of the DE particles gradually drops to zero, the addition amount of the BPFS is continuously increased, the adsorption surface of the BPFS-DE particles is wrapped by the excessive BPFS, the adsorption surface loses the opportunity of being combined with other DE, the adsorption reaction is not facilitated, and the unit adsorption amount and the chromaticity removal rate are reduced. As can be seen from fig. 2(B), as the stirring time increases, both the unit adsorption amount and the dye removal rate increase and then decrease. When the stirring time was 100min, the maximum values of the unit adsorption amount and the dye removal rate were 0.121mg/g and 57.5%, respectively. The stirring time is too short, and a stable BPFS-DE adsorbent is not formed; along with the increase of the stirring time, the BPFS and DE loading degree is good, and the unit adsorption amount and the dye removal rate are increased; when the stirring time is too long, BPFS particles are detached from the DE surface, which is not favorable for adsorption reaction. As can be seen from FIG. 2(C), the unit adsorption amount and the dye removal rate increase with the increase of temperature, the maximum values of the unit adsorption amount and the chromaticity removal rate are 0.156mg/g and 74% respectively when the adsorption temperature is 55 ℃, and the unit adsorption amount and the dye removal rate are significantly decreased when the temperature is more than 55 ℃, which indicates that the temperature is too high and the heat transport of the molecules is acceleratedAnd the BPFS-DE particles are subjected to coagulation, so that the stability of the BPFS-DE particles is influenced. This is consistent with the conclusion of Zheng Huai et al. As can be seen from fig. 2(D), as the pH value increases, both the unit adsorption amount and the dye removal rate tend to increase and decrease. Under acidic conditions, H+Has a competitive relationship with the combination of BPFS and DE, and the formed BPFS-DE is less under the condition of lower pH, so the unit adsorption amount and the dye removal rate are low, and H is increased along with the increase of the pH value+The content is reduced, the formation of the composite adsorbent is facilitated, and when the pH value is 4, the maximum values of the unit adsorption amount and the removal rate are respectively 0.165mg/g and 78%. As pH continues to rise, adsorption is poor because ABCK is an anionic dye.
Characterization of composite adsorbent (BPFS-DE)
The appearance of the purified Diatomaceous Earth (DE) samples and the composite adsorbent (BPFS-DE) was characterized and shown in FIG. 3.
As can be seen from FIG. 3(A), the impurities on the purified diatomite disks are dissolved and washed away, the specific surface area is large, the micropores in the middle and around the diatom body are completely exposed, and the diatom body is relatively intact. This indicates that the impurities on the surface of diatomaceous earth can be effectively removed by treatments such as acid washing and calcination, and that almost all micropores on the surface of diatomaceous earth are exposed. As can be seen from FIG. 3(B), after BPFS compound DE, the pore diameter of the surface micropores is significantly increased, the number of pores is significantly increased, and the distribution is uniform. The surface roughness is obviously increased, and BPFS particles are uniformly distributed on the surface of DE, which shows that BPFS can be effectively loaded on DE, changes the property of the surface of DE, increases the surface roughness and is beneficial to the occurrence of adsorption reaction.
FIG. 4 is a graph showing adsorption and desorption isotherms of purified Diatomaceous Earth (DE) and composite adsorbent (BPFS-DE). As can be seen from FIG. 4, the adsorption-desorption isotherms for DE and BPFS-DE belong to the type IV isotherm with a hysteresis loop of type H3. The pore channels on the surface of BPFS-DE include both the pore channels of DE itself and the pores formed by the accumulation of BPFS on the surface of DE. The specific surface areas of DE and BPFS-DE were 1.7177 m, respectively2·g-1And 7.6919 m2·g-1From the above, it can be seen that the specific surface area of the modified diatomite is obviously increased, which indicates that the diatomite is modified by BPFSThe adsorption performance of DE (5) is enhanced, and the adsorption amount of the DE to the dye is increased.
FIG. 5 is an XRD spectrum of purified Diatomaceous Earth (DE) and composite adsorbent (BPFS-DE). As can be seen from fig. 5, the curve shows the strongest peaks (corresponding to SiO) at 2 θ =21.8 ° and 2 θ =35.96 °2See JCPDS), indicating that BPFS modified DE did not change the crystal structure of DE. The characteristic peak of the composite adsorbent is slightly increased compared with DE, which is probably due to the fact that the composite adsorbent is modified by BPFS and coated with iron, and the characteristic peak shows that DE is modified to obviously change the microporous structure of the surface, which is consistent with the view of plum wave and the like. The Zeta potentials of the Diatomite (DE) and the composite adsorbent (BPFS-DE) are-66.1944 mV and-14.2813 mV respectively, and the determination result shows that the Zeta potential of the BPFS-DE is greatly improved compared with that of the DE because the BPFS is a complex hydroxyl bridging iron (III) polymer, and the BPFS is combined on the surface of the DE in the modification process, so that the electronegativity of the surface of the DE is reduced, dye molecules with negative charges can be better desorbed, and the removal rate of the dye is improved.
Adsorption performance of composite adsorbent on acidic chrome blue K
Effect of reaction conditions on complex adsorbents on ACBK dye: the effect of different adsorption times on the adsorption effect was examined by adding 2.5g BPFS-DE to 2mg/L ACBK wastewater and maintaining the other reaction conditions (rotation speed 300r/min, temperature 20 ℃ C.), with the results shown in FIG. 6 (A). As can be seen from fig. 6(a), as the reaction time increases, both the unit adsorption amount and the dye removal rate increase first and then decrease. When the reaction time is 20min, the maximum values of the unit adsorption amount and the dye removal rate are respectively 0.154mg/g and 74.6%, and the adsorption effect is best. In the initial stage of adsorption, a large number of adsorption vacancies and a high air diffusion speed exist on the BPFS-DE surface, and the dye solution contains enough ACBK adsorbate molecules, which provides a strong driving force for promoting the dye molecules to diffuse from the solution to the surface of the adsorbent, so that the adsorption reaches saturation when the reaction time is 20min, and as the adsorption sites on the BPFS-DE surface are occupied and the air diffusion speed is reduced, fewer and fewer free ACBK molecules in the solution exist, the adsorption reaction becomes slow, and the adsorption quantity and the dye removal rate are reduced.
In order to study the influence of the dye concentration on the adsorption effect, the adsorption reaction of ACBK wastewater was carried out with BPFS-DE at different concentrations, and other conditions (BPFS-DE dosage of 10g/L, rotation speed of 300r/min, temperature of 20 ℃ and adsorption time of 20min) were kept unchanged, and the results are shown in FIG. 6 (B). As can be seen from fig. 6(B), as the dye concentration increases, the unit adsorption amount increases, and the dye removal rate gradually decreases. When the dye concentration is 2mg/L, the larger value of the unit adsorption amount and the maximum value of the dye removal rate are respectively 0.177mg/g and 88.4%. With the increase of the dye concentration, the content of the adsorbent is smaller, the adsorbent per unit mass is surrounded by more dye molecules, so that the dye molecules are easier to combine with active sites on the adsorbent, and the unit adsorption amount is larger; the concentration of the dye is continuously increased, excessive dye molecules with negative charges are gathered on the surface of DE to shield the positive charges of the modified DE, and the adsorption capacity of the dye molecules is reduced due to the existence of electrostatic repulsion, so that the removal rate of the dye is reduced.
The pH of the wastewater is another important factor affecting the dye removal rate, since the pH of the solution affects the BPFS-DE surface-OH. Since ACBK is rose in acidic solution and blue-gray in alkaline solution, the pH range selected for this study was 4.0-8.0. FIG. 6(C) shows that, when the pH was 6, the adsorption effect was the best when the maximum values of the unit adsorption amount and the dye removal rate were 0.182mg/g and 98.4%, respectively. This is because the presence of a large amount of-OH on the BPFS-DE surface adds H with a change in pH+Or to remove H+. If the pH of the solution is too low, a large amount of H+Firstly, the compound is combined with BPFS-DE to occupy limited binding sites on the surface of the BPFS-DE, so that the unit adsorption amount and the dye removal rate are reduced, the surface of the BPFS-DE is protonated as the pH value is increased, ACBK belongs to anionic dye and has high affinity with cation, so that the unit adsorption amount and the dye removal rate are increased, and the hydroxyl group on the surface of the BPFS-DE is dehydro as the pH value is continuously increased+The surface negative charge amount thereof increases, so that the unit adsorption amount and the dye removal rate gradually decrease.
In order to investigate the influence of the addition of the adsorbent BPFS-DE on the adsorption effect, the ACBK wastewater was subjected to adsorption reaction with BPFS-DE at different addition amounts, respectively, and other conditions (rotation speed 300r/min, temperature 20 ℃, pH =6, reaction time 20min) were kept unchanged, and the results are shown in FIG. 6 (D). As can be seen from fig. 6(D), as the amount of addition increases, the unit adsorption amount and the dye removal rate increase and then decrease. When the adding amount is 14g/L, the maximum values of the unit adsorption amount and the removal rate are 0.197mg/g and 98.6 percent respectively, and the adsorption effect is best. The unit adsorption amount is reduced because the use amount of the adsorbent is increased, adsorption sites are increased, the amount of dye in the solution is insufficient, and the amount of the adsorbed dye cannot reach the amount required by the adsorption sites; the removal rate is increased because the dosage of the adsorbent is increased and adsorption sites are increased; when the addition amount of the BPFS-DE is continuously increased, the probability that the BPFS-DE in unit mass contacts dye molecules is reduced, so that the effective utilization rate of the BPFS-DE is reduced, and the dye removal rate is influenced.
In order to investigate the influence of the reaction temperature on the adsorption effect, the adsorption reaction was performed on the ACBK wastewater with BPFS-DE at different temperatures, respectively, and the other conditions (BPFS-DE addition of 14g/L, rotation speed of 300r/min, pH =6, reaction time of 20min) were maintained, and the results are shown in FIG. 6 (E). As can be seen from FIG. 6(E), the unit adsorption amount and the dye removal rate increase with increasing temperature, indicating that an endothermic reaction occurs during adsorption of the ACBK dye by BPFS-DE, and the temperature increases, and the reaction moves in the direction of adsorption. When the temperature was raised to 30 ℃, the specific adsorption amount and the removal rate of color were 0.193mg/g and 96.8%, respectively, and the reaction temperature was determined to be 30 ℃ in consideration of economic efficiency.
Comparative experiment results
Certain amounts of purified DE, BPFS and composite adsorbent BPFS-DE are respectively added into the ACBK dye wastewater, the dye removal rate is measured under the optimal condition, and the results are shown in Table 1.
TABLE 1 Effect of different agents on ACBK dye removal
As can be seen from Table 1, both DE and BPFS have a removing effect on ACBK dye, but have a poorer removing effect than the composite adsorbent BPFS-DE. Because the DE has limited adsorption capacity and is in a powder shape, the DE is difficult to separate solid from liquid, and the removal rate is low. The composite adsorbent combines the respective advantages of DE and BPFS, BPFS is positively charged, ACBK surface is negatively charged, adsorption mainly passes through electrostatic action, DE has large specific surface area and can physically adsorb ACBK dye, and when DE and ACBK are compounded, the composite adsorbent not only has the electrostatic adsorption effect of BPFS, but also plays the advantage of large specific surface area of DE, so that the overall adsorption effect is enhanced.
Adsorption kinetics of BPFS-DE to ACBK dye; the kinetic adsorption results of BPFS-DE adsorbing ACBK dye were simulated by using the first-order kinetic equation and the second-order kinetic equation, and the results are shown in FIG. 7 and FIG. 8.
As can be seen from FIGS. 7 and 8, the fitting adsorption effect of the pseudo-second order kinetic equation is good, and the correlation coefficientR= 0.90745. Thus, the adsorption reaction conforms to a quasi-second order kinetic equation. Calculating to obtain: rate constantk 2 =0.5318 g/mg.min, adsorption capacityQe=0.2094 mg/g. This suggests that the BPFS-DE adsorption process may be the diffusion of ACBK dye molecules from the outer surface into the inner surface of the adsorbent through the pores on the surface of the adsorbent, controlling the rate of the whole process.
Adsorption isotherm of BPFS-DE on ACBK dye: the adsorption of ACBK dye by BPFS-DE was described using Langmuir isotherms and Freundlich isotherms, and the results after fitting are shown in FIGS. 9 and 10.
As can be seen from fig. 9 and 10, fitting the experimental number with Langmuir isotherms has a large correlation coefficient, R = 0.98962. Thus, the adsorbed acid chrome blue K conforms to the Langmuir isotherm model. Calculating to obtain: adsorption capacity constant Kf=8.97mg/g, affinity constantn=-0.576L/mg。
2.3.5 adsorption thermodynamics of BPFS-DE to ACBK dye: by measuring the heat of adsorption of the adsorbate on the adsorbent, the main force of adsorption can be inferred, which is helpful for judging the adsorption mechanism. Assuming that adsorption is ideal, the thermodynamic parameter, Gibbs free energy variant, (is) is derived from the change in equilibrium constant of the adsorption isotherm with temperature△G 0 ) Change in enthalpy (△H 0 ) Entropy change (△S 0 )。
△G 0 Delta can be obtained from the following formulaG 0 =-RTlnK(ii) a In the formula (I), the compound is shown in the specification,Kare equilibrium constants of the Langmuir model at different temperatures. DeltaH 0 This can be derived from the Van' tHoff equation: lnCe=lnK 0 +(-△H 0 RT) (ii) a In the formula (I), the compound is shown in the specification,C e the mass concentration (mg/L) of ACBK in the solution at adsorption equilibrium;K 0 -Van't Hoff equation constants. DeltaS 0 It can be calculated from the Gibbs-Helmholtz equation:△S 0 =△H 0 -△G 0 /Tthe result calculated from the above formula is as follows:
delta in adsorption of ACBK in 20 ℃ conditionsG 0 At-23.16 kJ/mol, indicating that the adsorption process is spontaneous;△S 0 76.59J/k.mol, which shows that the randomness of a solid-liquid interface is increased in the ACBK adsorption process;△H 0 52.37kJ/mol, indicating that the adsorption process is endothermic, which is consistent with the conclusion that the adsorption of BPFS-DE to ACBK dye is influenced by temperature factors in the experimental process, and the temperature is increased to facilitate the adsorption. When in use△H 0 When the concentration is less than 4.2kJ/mol, the adsorption process is physical adsorption; when in use△H 0 When the concentration is more than 21kJ/mol, the adsorption process is chemical adsorption, and the adsorption process is chemical adsorption.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
Claims (6)
1. The composite modified diatomite is characterized in that: prepared by compounding Diatomite (DE) and Biological Polymeric Ferric Sulfate (BPFS).
2. The method for preparing the composite modified diatomite as claimed in claim 1, wherein the method comprises the following steps: the method comprises the following steps:
s1, under acidic condition, using mixed bacteria mainly containing thiobacillus ferrooxidans as biocatalyst and industrial FeSO4·7H2Taking O as a raw material and reticular polyurethane as a carrier, and preparing BPFS by adopting a microbial immobilization technology;
s2, soaking a proper amount of Diatomite (DE) in dilute hydrochloric acid for 24 hours, washing to be neutral, drying in an oven at 105 ℃, and roasting at 450 ℃ for 1 hour for later use;
s3, weighing 2g of the Diatomite (DE) obtained in the step S2 into a conical flask, adding a certain amount of 80g/L BPFS, adding 50mL of demineralized water, stirring for a period of time at the rotation speed of 300r/min, performing suction filtration to neutrality, and drying a filter cake to obtain the composite BPFS-DE adsorbent.
3. The method of claim 2, wherein: in step S3, BPFS was added in an amount of 0.09 mL.
4. The method of claim 2, wherein: in step S3, the stirring time is 100 min.
5. The use of the composite modified diatomaceous earth of claim 1, wherein: can be used for treating Acid Chrome Blue K (ACBK) dye wastewater.
6. The use of claim 5, wherein: the removal rate of 2mg/L ACBK dye reaches 98.6 percent under the conditions that the adding amount of the composite BPFS-DE adsorbent is 14g/L, the pH value is 6, the temperature is 30 ℃ and the oscillation time is 20 min.
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