CN114950343A - Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water - Google Patents

Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water Download PDF

Info

Publication number
CN114950343A
CN114950343A CN202210778812.3A CN202210778812A CN114950343A CN 114950343 A CN114950343 A CN 114950343A CN 202210778812 A CN202210778812 A CN 202210778812A CN 114950343 A CN114950343 A CN 114950343A
Authority
CN
China
Prior art keywords
fly ash
fes
loaded nano
water
preparation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210778812.3A
Other languages
Chinese (zh)
Inventor
郭旭颖
高新乐
刘威
胡志勇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Liaoning Technical University
Original Assignee
Liaoning Technical University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Liaoning Technical University filed Critical Liaoning Technical University
Priority to CN202210778812.3A priority Critical patent/CN114950343A/en
Publication of CN114950343A publication Critical patent/CN114950343A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0225—Compounds of Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt
    • B01J20/0229—Compounds of Fe
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
    • B01J20/0274—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04 characterised by the type of anion
    • B01J20/0285—Sulfides of compounds other than those provided for in B01J20/045
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/04—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of alkali metals, alkaline earth metals or magnesium
    • B01J20/041—Oxides or hydroxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/06—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
    • B01J20/08—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04 comprising aluminium oxide or hydroxide; comprising bauxite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
    • B01J20/103—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate comprising silica
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28057—Surface area, e.g. B.E.T specific surface area
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/28—Treatment of water, waste water, or sewage by sorption
    • C02F1/288—Treatment of water, waste water, or sewage by sorption using composite sorbents, e.g. coated, impregnated, multi-layered
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/70—Treatment of water, waste water, or sewage by reduction
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/20—Heavy metals or heavy metal compounds
    • C02F2101/22—Chromium or chromium compounds, e.g. chromates
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/10—Biological treatment of water, waste water, or sewage

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Analytical Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Abstract

A fly ash loaded nano FeS, a preparation method thereof and application of the fly ash loaded nano FeS in removing Cr in water belong to the technical field of water treatment composite materials. The preparation method comprises mixing fly ash and Na 2 S, adding water, stirring, mixing, reacting, and carrying out solid-liquid separation to obtain adsorbed S 2‑ The fly ash particles of (1); FeSO (ferric oxide) is added 4 The solution is dripped at uniform speed to adsorb S 2‑ FeS is generated in the fly ash particles, and suspension is obtained after ultrasonic treatment; after post-treatment, fly ash is obtainedAnd loading the nano FeS. The fly ash loaded nano FeS (nFeS-F) can simultaneously and efficiently remove Cr (VI) and Cr (III) in a water body through the combined action of the fly ash and the FeS, and can reduce and adsorb the heavy metal chromium ions in polluted water to reduce the toxicity of the water body.

Description

Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water
Technical Field
The invention relates to a fly ash loaded nano FeS, a preparation method thereof and application of the fly ash loaded nano FeS in removing Cr in water, and belongs to the technical field of water treatment composite materials.
Background
With the development of modern industry, a large amount of chromium-containing wastewater inevitably enters water and soil environments and harms human health. Chromium often exists in Cr (III) and Cr (VI) states in water, and has the characteristics of high toxicity, difficult degradation, difficult treatment and the like.
The treatment methods usually used include adsorption, ion exchange, biological, membrane separation, and the like. Wherein, the adsorption method has the problems of low unit removal amount of the adsorption material, low adsorption rate and the like; the ion exchange method has higher cost and is easy to cause secondary pollution; the biological method is difficult in strain screening work and has strict requirements on the growth environment; the membrane separation method has the advantages of high energy consumption, high operation cost and short service time of the membrane.
The nano FeS has the characteristics of surface effect, volume effect, strong reducibility, adsorbability and the like. However, the nano FeS has small particle size and relatively high surface energy, and is easy to agglomerate, so that the activity of the nano FeS is reduced. And the effect of treating the acidic chromium-containing wastewater by the nano FeS is not clear.
The fly ash is an industrial waste with high porosity and large specific surface area, and when the fly ash is added into chromium-polluted water, Cr (III) and Cr (VI) can enter pores of the fly ash structure to be adsorbed, fixed and precipitated, thereby playing a role in reducing toxicity. Obviously, the adsorption capacity of the common fly ash is limited, and the possibility of the desorbed chromium ions entering the water body again exists.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides the fly ash loaded nano FeS, the preparation method thereof and the application thereof in removing Cr in water, wherein the fly ash loaded nano FeS (nFeS-F) can simultaneously and efficiently remove Cr (VI) and Cr (III) in water through the combined action of the fly ash and the FeS, and can be reduced and adsorbed in polluted water containing heavy metal chromium ions to reduce the toxicity of the water.
The fly ash loaded nano FeS prepared by the method has high specific surface area, and the chromium content in the solution is kept stable through a dynamic test of 600h, which shows that the fly ash loaded nano FeS has long-term stability, has good effects on the removal rate and adsorption capacity of Cr (VI) and total chromium, and has the advantages of easy separation from the solution and the like. The method is characterized in that the surface groups of the fly ash and the reducibility of FeS are utilized to reduce Cr (VI) in the water body into Cr (III), the Cr (III) is migrated and fixed on the surface of nFeS through charge adsorption, ion exchange is further carried out, a stable complex is generated, the size of the complex is large and stable, and finally the Cr (VI) and the Cr (III) are simultaneously removed from the water body.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the invention discloses a preparation method of fly ash loaded nano FeS, which comprises the following steps:
step 1: mixing fly ash and Na 2 S, adding water, stirring, mixing, reacting, and carrying out solid-liquid separation to obtain adsorbed S 2- The fly ash particles of (1); according to the mass ratio, the fly ash: na (Na) 2 S＝(2～8):60。
Step 2:
FeSO (ferric oxide) is added 4 Prepared into FeSO 4 The solution is dripped into the solution adsorbed with S at a constant speed 2- In fly ash particles of (2) so that FeSO is present 4 And S 2- Reacting to generate FeS, and performing ultrasonic treatment to obtain suspension; wherein, according to the molar ratio of S 2- ：Fe 2+ ＝1:(1～1.1)；
And step 3:
removing the supernatant from the suspension to obtain an initial product;
and cleaning and vacuum drying the initial product to obtain the fly ash loaded nano FeS (nFeS-F).
In the step 1, according to the solid-liquid ratio, the weight ratio of the fly ash: water ═ 4-5 g: (200) 220) mL.
In the step 1, the stirring and mixing reaction is carried out for 8-24h, preferably 8-10h, and the stirring rate is 1200-2000 r/min.
In the step 1, the particle size of the fly ash is 120-150 meshes.
In the step 2, FeSO 4 The molar concentration of the solution is 0.15-0.75 mol/L.
In the step 2, the dropping speed is 0.15-0.60 mL/s.
In the step 2, the ultrasonic frequency is 20-40 kHz, and the ultrasonic time is 5-20 min.
In the step 3, the supernatant is removed by centrifugal separation at 2500-4000rpm for 10-20 min.
In the step 3, the temperature of vacuum drying is 100-120 ℃, and the drying time is 1-2 hours.
The fly ash loaded nano FeS is prepared by the method, and the specific surface area of FeS on nFeS-F is 101.36-115.29m 2 The particle size of FeS is 40-80 nm.
According to the application of the fly ash loaded nano FeS in removing Cr in water, the removal rate of Cr (VI) is more than or equal to 80%, the removal rate of total chromium is more than or equal to 79%, the adsorption capacity of Cr (VI) is more than or equal to 37.15mg/g, and the adsorption capacity of total chromium is more than or equal to 33.41 mg/g.
The application of the fly ash loaded nano FeS in removing Cr in water can remove heavy metal polluted water with Cr metal concentration of 0.5-200mg/L and pH less than or equal to 8, the removal rates of Cr (VI) and total chromium can respectively reach 92.87% and 83.53%, and when the concentration of a chromium solution reaches more than 200mg/L, the removal rate of total chromium is continuously reduced because Cr (III) with rapidly increased concentration in the solution cannot be removed; when the pH value of the solution is less than or equal to 8, the removal rate of Cr (VI) can reach 92.87% in 1h, the pH value is more than 9, and the removal capability is obviously inhibited.
The application of the fly ash loaded nano FeS in removing Cr in water is that the mass of the added fly ash loaded nano FeS is determined according to the content of Cr in water, and the specific calculation formula is as follows:
n 1 ：n 2 10, wherein n 1 Amount of nFeS-F substance, n 2 Is the amount of Cr in the water.
The specific operation process is as follows: placing the nFeS-F into heavy metal polluted water, stirring, removing the Cr (VI) within 1h to reach more than 80%, reacting for 2.5h, and separating supernatant to obtain the water with the Cr content of less than 7.13mg/g after removal.
The main passivation mechanism of nFES-F on Cr is CrO 4 2- 、HCr 2 O 7- Anion exchange enters the interlayer of the fly ash, and the main adsorption mechanism for fixing the fly ash is as follows: the nano FeS attached on the fly ash is ionized to generate Fe 2+ And S 2- Has strong reducing effect and can convert CrO 4 2- 、HCr 2 O 7－ The two react with Cr (VI) to reduce Cr (VI) into Cr 3+ To remove Cr 6+ The purpose of (1) is to reduce the toxicity of pollutants; in the process Fe 2+ Is oxidized into Fe 3+ In Cr (III); meanwhile, Fe exists on the surface of silicon and aluminum oxide in the fly ash under the condition that a large amount of-OH-exists 3+ Reducing groups such as Fe and the like are more easily formed, and can react with Cr (VI) to generate Cr (III) and form oxygen-containing groups, the oxygen-containing groups and the Cr (III) form a-O-Cr-O structure, and chemical bonding adsorption is generated through Si-O-Si bonds, Al-O-Al bonds and the-O-Cr-O structure contained in the surface of the oxygen-containing groups, so that the removal of chromium ions is further promoted; finally, the chromium ions are made into Cr (OH) 3 With Cr 3+ Coprecipitating Cr 3+ Fixed and adsorbed on fly ash, etc. to form a chromium-rich layer to be attached on the surface of nFeS-F. The application removes the high-toxicity Cr in the wastewater by skillful design of a new composite material and utilizing the synergistic effects of oxidation reduction, ion exchange, chemical bonding and the like, and has high removal rate and simple and convenient process.
The preparation method of the fly ash loaded nano FeS adopts a reduction precipitation method, and the composite material prepared by the method not only can adsorb, fix and enrich Cr (VI), but also has strong reducing capability, can convert the Cr (VI) into Cr (III) with lower toxicity on the surface of the fly ash, and is further fixed in a fly ash structure body, so that the aim of reducing and precipitating pollutant chromium is achieved.
The technical scheme of the invention has the following beneficial effects:
1) the FeS adopted by the invention is nano-scale FeS, has the advantages of large specific surface area, small particle size and the like, and can be better loaded on the fly ash.
2) Compared with fly ash, the synthesized nFES-F composite material not only can exchange and adsorb chromium ions, but also can be chemically converted into Cr (III) with lower toxicity, and can be completely adsorbed and fixed on the fly ash-loaded nano FeS, so that the Cr removal efficiency in water is higher; because of the participation of chemical reaction, the former has faster rate of chromium exchange and adsorption and is less susceptible to interference of other ions.
3) The research shows that the preparation method of the nFES-F composite material is simple and the synthesis efficiency is high.
4) The research realizes triple synergistic effects of oxidation reduction, ion exchange and chemical bonding in the process of removing high-toxicity Cr in the wastewater through the ingenious design of a new composite material.
Drawings
FIG. 1 is an XRD pattern of fly ash prepared in example 1 of the present invention and nFES-F.
FIG. 2 is a photograph of nFES-F TEM prepared in example 1.
FIG. 3 is a graph comparing the effect of different fly ash size fractions prepared in example 1 on Cr (VI) and total chromium removal.
FIG. 4 shows different FeSO's prepared in example 1 4 The effect of concentration on Cr (VI) and total chromium removal rate is compared with the figure.
FIG. 5 is a graph comparing the effect of different dropping flow rates on Cr (VI) and total chromium removal as prepared in example 1.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention, but not to limit the scope of the invention, which is defined by the claims. Unless otherwise specified, the test reagents and materials used in the examples of the present invention are commercially available. Unless otherwise specified, the technical means used in the examples of the present invention are conventional means well known to those skilled in the art.
In the following examples, the Cr content of the supernatant was determined by the following method; measuring the concentration of total chromium (Cr (T)) in the supernatant by using a potassium permanganate oxidation-diphenylcarbazide spectrophotometry; the concentration of hexavalent chromium (Cr (vi)) was measured by dibenzoyl dihydrazide spectrophotometry.
Example 1
Weighing 4g of 150-mesh fly ash with the particle size fraction of 120- 2 S is placed in a conical flask, deionized water is added, stirring is carried out for 8 hours, and then Na is poured out 2 S solution to obtain adsorbed S 2- The fly ash particles of (1).
0.45mol/L of FeSO is pumped by a peristaltic pump 4 Dropwise adding the solution into the prepared conical flask at a constant speed of 0.45mL/s, and performing ultrasonic treatment at 40kHz frequency for 10min to obtain suspension; wherein, in terms of molar ratio, S 2- ：Fe 2+ ＝1:1.1；
And pouring the suspension into a centrifuge tube, centrifuging for 15min, washing impurities by using deionized water, and performing vacuum drying in a vacuum drying oven to obtain the fly ash-loaded nano FeS (nFeS-F).
FIG. 1 is an XRD pattern of fly ash prepared in example 1 of the present invention along with nFES-F; the characteristic diffraction peaks of the loaded nFeS-F at 2 theta of 20.85 degrees, 26.62 degrees, 50.11 degrees and 68.10 degrees all exist, which shows that the original crystal structure of the fly ash is not changed by the fly ash loaded nano FeS; the loaded nFeS-F shows FeS diffraction peaks at 2 theta of 32.68 degrees and 43.17 degrees, which indicates that the FeS is successfully loaded on the surface of the fly ash. A new composite nFeS-F is formed.
FIG. 2 is a TEM image of nFES-F prepared in example 1, showing that the FeS crystals loaded on the surface of fly ash are flaky and have an average length of 40-80nm, which illustrates that the ultrasonic precipitation method can load nano FeS on the fly ash particles; the nano FeS is uniformly distributed in the nFeS-F, and the dispersion degree is good, so that the coal ash is used as a carrier material to effectively improve the stability of the nano FeS and inhibit the self coagulation and agglomeration of the nano FeS.
Example 2
Weighing 4g of 150-mesh fly ash with the particle size fraction of 120- 2 S is placed in a conical flask, deionized water is added, stirring is carried out for 8 hours, and then Na is poured out 2 S solution to obtain adsorbed S 2- The fly ash particles of (1).
0.45mol/L of FeSO is pumped by a peristaltic pump 4 The solution was added dropwise at a constant rate of 0.33mL/s to the above prepared Erlenmeyer flask, and ultrasonic waves were applied at a frequency of 40kHzTreating for 10min to obtain suspension; wherein, in terms of molar ratio, S 2- ：Fe 2+ ＝1:1.1；
And pouring the suspension into a centrifuge tube, centrifuging for 15min, washing impurities by using deionized water, and performing vacuum drying in a vacuum drying oven to obtain the fly ash loaded nano FeS (nFeS-F).
Example 3
Weighing 4g of 150-mesh fly ash with the particle size fraction of 120- 2 S is placed in a conical flask, deionized water is added, stirring is carried out for 8 hours, and then Na is poured out 2 S solution to obtain adsorbed S 2- The fly ash particles of (1).
0.45mol/L of FeSO is pumped by a peristaltic pump 4 Dropwise adding the solution into the prepared conical flask at a constant speed of 0.53mL/s, and performing ultrasonic treatment at 40kHz frequency for 10min to obtain suspension; wherein, in terms of molar ratio, S 2- ：Fe 2+ ＝1:1.1；
And pouring the suspension into a centrifuge tube, centrifuging for 15min, washing impurities by using deionized water, and performing vacuum drying in a vacuum drying oven to obtain the fly ash loaded nano FeS (nFeS-F).
Example 4
Weighing 4g of 150-mesh fly ash with the particle size fraction of 120- 2 S is placed in a conical flask, deionized water is added, stirring is carried out for 8 hours, and then Na is poured out 2 S solution to obtain adsorbed S 2- The fly ash particles of (1).
0.60mol/L of FeSO is pumped by a peristaltic pump 4 Dropwise adding the solution into the prepared conical flask at a constant speed of 0.33mL/s, and performing ultrasonic treatment at 40kHz frequency for 10min to obtain suspension; wherein, in terms of molar ratio, S 2- ：Fe 2+ ＝1:1.1；
And pouring the suspension into a centrifuge tube, centrifuging for 15min, washing impurities by using deionized water, and performing vacuum drying in a vacuum drying oven to obtain the fly ash loaded nano FeS (nFeS-F).
Example 5
Weighing 4g of 150-mesh fly ash with the particle size fraction of 120- 2 S is placed in a conical flask, deionized water is added, stirring is carried out for 8 hours, and then Na is poured out 2 S solution to obtain adsorbed S 2- Fly ash ofAnd (3) granules.
0.45mol/L of FeSO is pumped by a peristaltic pump 4 Dropwise adding the solution into the prepared conical flask at a constant speed of 0.33mL/s, and performing ultrasonic treatment at 30kHz frequency for 10min to obtain suspension; wherein, in terms of molar ratio, S 2- ：Fe 2+ ＝1:1.1；
And pouring the suspension into a centrifuge tube, centrifuging for 15min, washing impurities by using deionized water, and performing vacuum drying in a vacuum drying oven to obtain the fly ash loaded nano FeS (nFeS-F).
Example 6
This example is a comparison of the effect of different fly ash fractions synthesized in example 1 on Cr-contaminated wastewater.
The Cr-polluted wastewater is an aqueous solution prepared from potassium dichromate, and the Cr concentration C in the aqueous solution 1 Is 100 mg/L. The addition amount of nFES-F was 5.0g/L, and the pH was 4. The process is as follows: respectively adding 200mL of Cr polluted wastewater and 1g of nFES-F into a conical flask, placing the conical flask on a magnetic stirrer for stirring, and filtering impurities and extracting supernatant after 2min, 5min, 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 120min and 150min respectively; the concentration of Cr (T) in the clear solution was determined by potassium permanganate oxidation-diphenylcarbodihydrazide spectrophotometry, and the concentration of Cr (VI) was determined by diphenylcarbodihydrazide spectrophotometry (the same applies hereinafter). Calculating formula eta (C) by using removal rate (eta) 1 -C 2 )/C 1 (wherein, C 1 Indicating the Cr concentration, C, in the Cr-contaminated wastewater before adsorption 2 The same applies hereinafter to the concentration of Cr in the solution after adsorption), the removal rate under different conditions was calculated. So as to research the difference of the effect of the composite material on removing Cr-polluted wastewater under the influence of different fly ash particle sizes.
FIG. 3 is a graph comparing the effect of different fly ash size fractions prepared in example 1 on Cr (VI) and total chromium removal; shown in FeSO 4 The mass concentration of the substance is 0.45mol/L, FeSO 4 When the dropping flow rate is 0.53mL/s, the removal rate of nFeS-F to Cr (VI) and total chromium shows a trend of increasing and then decreasing along with the gradual decrease of the size fraction of the fly ash. When the particle size fraction of the fly ash is 120-150 meshes, the removal rate of Cr (VI) and total chromium reaches the maximum of 92.09 percent and 80.27 percent. This is because the fly ash particle sizeThe specific surface area is increased, and the adsorption capacity to chromium is enhanced. Meanwhile, the specific surface area of the fly ash is increased, and the adsorption sites are gradually increased, so that the fly ash is loaded with more FeS. Studies have shown that nFeS-F adsorption of Cr (VI) consumes H + Meanwhile, the nFeS-F surface is positively charged, and the removal rate of Cr (VI) is improved by charge adsorption. When the particle size of the fly ash is too small, the prepared nFES-F is easy to float on the water surface and is difficult to settle in the process of treating chromium-containing wastewater, so that the removal effect is influenced. Therefore, the purpose of 120-150 is selected as the subsequent experiment coal ash particle size fraction.
Example 7
This example is a different FeSO prepared using example 1 4 And (3) comparing the effect of the concentration on the removal rate of the Cr polluted wastewater.
The Cr concentration in the wastewater was 100 mg/L. The addition amount of nFES-F was 5.0g/L, and the pH was 4. The process is as follows: respectively adding 200ml of simulated Cr polluted wastewater and 1g of nFES-F into a conical flask, placing the conical flask on a magnetic stirrer for stirring, and filtering impurities and extracting supernatant after 2min, 5min, 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 120min and 150min respectively; and calculating the removal rate of the chromium pollution wastewater under different conditions. To study different FeSO 4 The difference of the effect of the concentration on the removal rate of Cr polluted wastewater.
FIG. 4 shows different FeSO's prepared in example 1 4 A comparison graph of the effect of the concentration on the Cr (VI) and the total chromium removal rate; when FeSO 4 When the mass concentration of the substances is 0.45mol/L, the removal rates of Cr (VI) and total chromium reach maximum values, namely 92.58 percent and 82.99 percent respectively. This is due to FeSO 4 The solution concentration has a great influence on the nucleation and growth rate of the crystals. Fe constituting FeS crystals in solution 2+ An increase in ion concentration is more favorable for an increase in the number of crystal grains. With FeSO 4 The concentration is increased, a large number of tiny crystal grains are rapidly generated, a larger collision area and more active sites can be provided, and therefore the Cr (VI) and total chromium removal rate is increased. With FeSO 4 The amount concentration of the substances continues to increase, the Cr (VI) and total chromium removal rate does not significantly increase, and the Fe in the solution is shown 2+ The concentration is already close to saturation, so 0.45mol/L is selected as FeSO in the subsequent experiment 4 The quantitative concentration of the substance.
Example 8
This example is a comparison of the effect of using different dropping flow rates prepared in example 1 on the removal of Cr contaminated wastewater.
The Cr concentration in the wastewater was 100 mg/L. The addition amount of nFES-F was 5.0g/L, and the pH was 4. The process is as follows: respectively adding 200ml of Cr polluted wastewater and 1g of nFES-F into a conical flask, placing the conical flask on a magnetic stirrer for stirring, and filtering impurities after 2min, 5min, 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 120min and 150min respectively, and then extracting supernatant; and calculating the removal rate. So as to research the difference of the influence effect of different dripping flow rates on the removal rate of the Cr polluted wastewater.
FIG. 5 is a graph comparing the effect of different dropping flow rates on Cr (VI) and total chromium removal as prepared in example 1; shows that the particle size fraction of the fly ash is 120-150 meshes, FeSO 4 When the mass concentration of the substance is 0.45mol/L, the removal rate of nFeS-F to Cr (VI) and total chromium shows a trend of increasing and then decreasing along with the increase of the dropping flow rate. When the dropping flow rate is 0.33mL/s, the removal rates of Cr (VI) and total chromium reach maximum values, which are 89.15% and 79.68%, respectively. The reason is that the dropping flow rate of the solution has influence on the crystal structure of the FeS, and the supersaturation nucleation and growth rate theory proves that the dropping flow rate is in direct proportion to the nucleation rate and the growth rate of the FeS crystal. When the dropping flow rate is small, the grain diameter of the generated crystal nucleus is small, and the crystal nucleus has higher surface free energy, so that the removal rate of Cr (VI) and total chromium is maximum. When the dropping flow rate is increased, the crystal particle diameter is rapidly increased and the specific surface area is reduced, resulting in a reduction in the removal effect of Cr (VI) and total chromium. Taken together, 0.43mL/s was selected as the dropwise addition flow rate for the subsequent experiment.
Comparative example 1
This comparative example provides the use of a kaolinite-loaded FeS (FeS-Kaolinite) for treating chromium-containing wastewater, the preparation of which is described in example 1, except that the replacement support material is kaolinite.
The method for treating the chromium-containing heavy metal wastewater by using the kaolinite loaded FeS has the advantages that the removal rate of the heavy metal chromium wastewater is 76.8 percent, and the FeS-kalinite ratio table is shown in example 6The area is 31.68m 2 Per g, FeS specific surface area on FeS-Kaolinite is about 101.18m 2 /g。
It is stated that not all materials capable of being supported can achieve the effects of high removal rate and large specific surface area. The coal ash cannot be crystallized due to sudden change from high-temperature combustion to low-temperature cooling in the coal burning process, and the main structure of the coal ash is mainly a large amount of Si-Al fused glass body structure, so that the coal ash has a plurality of pore passages, a large specific surface area and adsorption performance.
Comparative example 2
This comparative example provides the use of fly ash directly added to FeS for the treatment of chromium containing wastewater, the preparation of which is described in example 1, except that loading was carried out untreated.
When the fly ash is added into FeS for removing Cr in water, the removal rate of Cr (VI) and the total chromium can respectively reach 63.44 percent and 51.62 percent when the concentration of Cr metal in the removed water is 0.5-100 mg/L; when the concentration of the chromium solution reaches more than 100mg/L, the agglomeration phenomenon is obvious due to the increase of the corresponding FeS addition amount, and the total chromium removal rate is continuously reduced.
Comparative example 3
The application of the fly ash directly used for treating the chromium-containing wastewater has poor adsorption effect when the fly ash is independently used as an adsorbent for treating the chromium-containing wastewater, the removal rate of the heavy metal chromium wastewater is 41.40%, the adsorption quantity is limited, and a large amount of sludge is generated when the fly ash is excessively used, so that secondary pollution is caused.
Comparative example 4
The application of FeS directly used for treating chromium-containing wastewater has the advantages that FeS is used as an adsorbent, the FeS has the characteristics of small particle size, high surface energy, unstable particles and the like, the removal rate of the heavy metal chromium wastewater is 70.26%, and meanwhile, the FeS is used as the adsorbent independently and is easy to agglomerate, so that the activity of the FeS is reduced, and the removal effect is influenced.
The above embodiments are merely illustrative of specific embodiments of the present invention, and do not limit the scope of the present invention, and those skilled in the art can make modifications based on the prior art. Without departing from the spirit of the invention, it is intended that all changes and modifications that may be effected by one of ordinary skill in the art to the disclosed embodiments be within the scope and range of equivalents of the invention as defined by the claims appended hereto.

Claims (10)

1. The preparation method of the fly ash loaded nano FeS is characterized by comprising the following steps:
step 1: mixing fly ash and Na 2 S, adding water, stirring, mixing, reacting, and carrying out solid-liquid separation to obtain adsorbed S 2- The fly ash particles of (1); according to the mass ratio, the fly ash: na (Na) 2 S＝(2～8):60；
Step 2:
FeSO (ferric oxide) is added 4 Is prepared into FeSO 4 The solution is dripped into the solution adsorbed with S at a constant speed 2- In fly ash particles of (2) so that FeSO is present 4 And S 2- Reacting to generate FeS, and performing ultrasonic treatment to obtain suspension; wherein, according to the molar ratio of S 2- ：Fe 2+ ＝1:(1～1.1)；
And step 3:
removing the supernatant from the suspension to obtain an initial product;
and cleaning and vacuum drying the initial product to obtain the fly ash loaded nano FeS.
2. The method for preparing nano FeS loaded by fly ash as claimed in claim 1, wherein in the step 1, the ratio of fly ash: water ═ 4-5) g: (200) 220) mL.
3. The method for preparing FeS loaded with pulverized fuel ash as claimed in claim 1, wherein in step 1, the stirring and mixing reaction is carried out for 8-24h at a stirring speed of 1200-2000 r/min.
4. The preparation method of the fly ash-loaded nano FeS as claimed in claim 1, wherein in the step 1, the particle size of the fly ash is 120-150 meshes.
5. The fly ash load of claim 1The preparation method of the nano FeS is characterized in that in the step 2, FeSO is used 4 The molar concentration of the solution is 0.15-0.75 mol/L.
6. The preparation method of the fly ash-loaded nano FeS as claimed in claim 1, wherein in the step 2, the dropping rate is 0.15-0.60 mL/s.
7. The preparation method of the fly ash-loaded nano FeS as claimed in claim 1, wherein in the step 2, the ultrasonic frequency is 20-40 kHz, and the ultrasonic time is 5-20 min.
8. The method for preparing the fly ash loaded nano FeS as claimed in claim 1, wherein in the step 3, the supernatant removal is performed by centrifugal separation at 2500-4000rpm for 10-20 min;
and/or the temperature of vacuum drying is 100-120 ℃, and the drying time is 1-2 h.
9. The fly ash-loaded nano FeS is characterized by being prepared by the method of any one of claims 1 to 8, and the specific surface area of the FeS on the fly ash-loaded nano FeS is 101.36-115.29m 2 The particle size of FeS is 40-80 nm.
10. The application of the fly ash loaded nano FeS in removing Cr from water as claimed in claim 9, wherein the fly ash loaded nano FeS is placed in heavy metal polluted water and stirred, the removal rate of Cr (VI) is more than or equal to 80%, the removal rate of total chromium is more than or equal to 79%, the adsorption capacity of Cr (VI) is more than or equal to 37.15mg/g, and the adsorption capacity of total chromium is more than or equal to 33.41 mg/g.
CN202210778812.3A 2022-07-04 2022-07-04 Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water Pending CN114950343A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210778812.3A CN114950343A (en) 2022-07-04 2022-07-04 Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210778812.3A CN114950343A (en) 2022-07-04 2022-07-04 Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water

Publications (1)

Publication Number Publication Date
CN114950343A true CN114950343A (en) 2022-08-30

Family

ID=82967447

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210778812.3A Pending CN114950343A (en) 2022-07-04 2022-07-04 Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water

Country Status (1)

Country Link
CN (1) CN114950343A (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101481465B1 (en) * 2013-08-27 2015-01-13 한국지질자원연구원 Method for manufacturing iron sulfide coated Porous supporter and iron sulfide coated Porous supporter manufactured by samemethod
CN106492752A (en) * 2016-10-27 2017-03-15 辽宁石油化工大学 A kind of adsorbent new preparation process for processing waste water containing chrome
CN106698582A (en) * 2017-01-24 2017-05-24 天津师范大学 Method for treating industrial wastewater containing heavy metal contaminants by utilizing industrial fly ash and nano iron
CN114195246A (en) * 2021-09-29 2022-03-18 河南力浮科技有限公司 Preparation of nanoscale FeS/LDH composite material and application of nanoscale FeS/LDH composite material in passivation removal of chromium in water

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101481465B1 (en) * 2013-08-27 2015-01-13 한국지질자원연구원 Method for manufacturing iron sulfide coated Porous supporter and iron sulfide coated Porous supporter manufactured by samemethod
CN106492752A (en) * 2016-10-27 2017-03-15 辽宁石油化工大学 A kind of adsorbent new preparation process for processing waste water containing chrome
CN106698582A (en) * 2017-01-24 2017-05-24 天津师范大学 Method for treating industrial wastewater containing heavy metal contaminants by utilizing industrial fly ash and nano iron
CN114195246A (en) * 2021-09-29 2022-03-18 河南力浮科技有限公司 Preparation of nanoscale FeS/LDH composite material and application of nanoscale FeS/LDH composite material in passivation removal of chromium in water

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
付赛欧: ""褐煤负载纳米FeS制备及其处理酸性含铬废水试验研究"", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》, no. 03, pages 021 - 918 *

Similar Documents

Publication Publication Date Title
CN106750356A (en) A kind of method that metal-organic framework materials of utilization UiO 66 purify selenium-containing wastewater
CN107983306A (en) A kind of activated carbon-carried nano iron oxide adsorbent and preparation method thereof
CN106698582A (en) Method for treating industrial wastewater containing heavy metal contaminants by utilizing industrial fly ash and nano iron
CN112915972A (en) high-Cr (VI) adsorption amount core-shell structure high-molecular magnetic nanosphere and preparation method and application thereof
CN104039711B (en) Water purification composition containing magnesia and its application
CN114797783B (en) Adsorbent for selectively removing Cr (VI) and preparation method and application thereof
CN113368812B (en) Co3O4Halloysite composite material, preparation method and application
CN112108107A (en) Arsenic adsorption material, preparation method thereof and application thereof in deep dearsenification
CN104475010B (en) Modified silica sand of porous silica and preparation method thereof
CN102357323B (en) Nanometer iron oxide-modified quartz sand filter material and preparation method thereof
CN112892476A (en) Biochar composite material and preparation method and application thereof
CN113441108A (en) Preparation method of modified attapulgite loaded nano zero-valent iron heavy metal adsorbent, product and application thereof
CN114425305B (en) Mercury adsorption material, preparation method thereof and application thereof in flue gas or solution mercury removal
CN109174066A (en) A kind of preparation method of nano lanthanum oxide de-fluoridation adsorbent
CN110624507A (en) Preparation method and adsorption performance of 4A molecular sieve composite material
CN113117643A (en) Modified biomass charcoal adsorption material, preparation method and application thereof, and method for regenerating modified biomass charcoal adsorption material
Chen et al. Adsorption properties and mechanism of Cd2+ in water by Zr-containing silica residue purification
CN114950343A (en) Fly ash loaded nano FeS, preparation method thereof and application of fly ash loaded nano FeS in removing Cr in water
CN117339551A (en) Composite material synthesis method with reduction and adsorption effects on tellurium
CN109694114B (en) Application of aluminum-substituted ferrihydrite in heavy metal adsorption
CN112808247B (en) Composite mercury removal material and preparation method and application thereof
CN113559825B (en) Preparation method, product and application of ZIF-8/sodium bentonite composite material
CN111036171A (en) Magnetic clay mineral material and preparation method and application thereof
CN106215851B (en) Preparation method and application of copper reagent modified nano aluminum oxide
CN109012571B (en) Modified electrolytic manganese waste residue, preparation method thereof and industrial wastewater treatment method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination