CN115400722B - Modified diatomite loaded ferrous sulfide composite material and preparation method and application thereof - Google Patents
Modified diatomite loaded ferrous sulfide composite material and preparation method and application thereof Download PDFInfo
- Publication number
- CN115400722B CN115400722B CN202211003305.9A CN202211003305A CN115400722B CN 115400722 B CN115400722 B CN 115400722B CN 202211003305 A CN202211003305 A CN 202211003305A CN 115400722 B CN115400722 B CN 115400722B
- Authority
- CN
- China
- Prior art keywords
- ferrous sulfide
- composite material
- diatomite
- modified diatomite
- modified
- 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.)
- Active
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical class O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 134
- MBMLMWLHJBBADN-UHFFFAOYSA-N Ferrous sulfide Chemical compound [Fe]=S MBMLMWLHJBBADN-UHFFFAOYSA-N 0.000 title claims abstract description 115
- 239000002131 composite material Substances 0.000 title claims abstract description 73
- 238000002360 preparation method Methods 0.000 title claims abstract description 18
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 claims abstract description 60
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims abstract description 57
- 235000006408 oxalic acid Nutrition 0.000 claims abstract description 19
- 239000000725 suspension Substances 0.000 claims description 25
- 239000002351 wastewater Substances 0.000 claims description 24
- 150000002500 ions Chemical class 0.000 claims description 14
- 229910001385 heavy metal Inorganic materials 0.000 claims description 12
- 238000003756 stirring Methods 0.000 claims description 12
- 239000007788 liquid Substances 0.000 claims description 8
- 238000000926 separation method Methods 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 3
- 238000001179 sorption measurement Methods 0.000 abstract description 43
- 230000009467 reduction Effects 0.000 abstract description 21
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 21
- 238000006243 chemical reaction Methods 0.000 abstract description 16
- 239000000126 substance Substances 0.000 abstract description 9
- 230000001603 reducing effect Effects 0.000 abstract description 7
- 238000004065 wastewater treatment Methods 0.000 abstract description 7
- 239000010842 industrial wastewater Substances 0.000 abstract description 3
- 231100000086 high toxicity Toxicity 0.000 abstract description 2
- 238000005554 pickling Methods 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 13
- 238000000034 method Methods 0.000 description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 10
- 239000011651 chromium Substances 0.000 description 10
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 9
- 229910052804 chromium Inorganic materials 0.000 description 9
- 150000001450 anions Chemical group 0.000 description 8
- 239000002245 particle Substances 0.000 description 8
- 239000002253 acid Substances 0.000 description 7
- 239000008367 deionised water Substances 0.000 description 7
- 229910021641 deionized water Inorganic materials 0.000 description 7
- 230000004048 modification Effects 0.000 description 7
- 238000012986 modification Methods 0.000 description 7
- 239000011148 porous material Substances 0.000 description 7
- 239000000243 solution Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- VQWFNAGFNGABOH-UHFFFAOYSA-K chromium(iii) hydroxide Chemical group [OH-].[OH-].[OH-].[Cr+3] VQWFNAGFNGABOH-UHFFFAOYSA-K 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 5
- 238000002386 leaching Methods 0.000 description 5
- 238000011068 loading method Methods 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 239000003463 adsorbent Substances 0.000 description 4
- 238000005054 agglomeration Methods 0.000 description 4
- 230000002776 aggregation Effects 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 3
- 238000013507 mapping Methods 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000002835 absorbance Methods 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 150000001768 cations Chemical class 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000003795 desorption Methods 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- SURQXAFEQWPFPV-UHFFFAOYSA-L iron(2+) sulfate heptahydrate Chemical compound O.O.O.O.O.O.O.[Fe+2].[O-]S([O-])(=O)=O SURQXAFEQWPFPV-UHFFFAOYSA-L 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 230000000051 modifying effect Effects 0.000 description 2
- 230000005588 protonation Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 229940048181 sodium sulfide nonahydrate Drugs 0.000 description 2
- WMDLZMCDBSJMTM-UHFFFAOYSA-M sodium;sulfanide;nonahydrate Chemical group O.O.O.O.O.O.O.O.O.[Na+].[SH-] WMDLZMCDBSJMTM-UHFFFAOYSA-M 0.000 description 2
- 238000000967 suction filtration Methods 0.000 description 2
- 150000004763 sulfides Chemical class 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 231100000331 toxic Toxicity 0.000 description 2
- 230000002588 toxic effect Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229910001430 chromium ion Inorganic materials 0.000 description 1
- 239000002734 clay mineral Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- VDQVEACBQKUUSU-UHFFFAOYSA-M disodium;sulfanide Chemical compound [Na+].[Na+].[SH-] VDQVEACBQKUUSU-UHFFFAOYSA-M 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 230000005802 health problem Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 239000010985 leather Substances 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 238000003911 water pollution Methods 0.000 description 1
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
- B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
- B01J20/14—Diatomaceous earth
-
- 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
-
- 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
- C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/06—Controlling or monitoring parameters in water treatment pH
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Inorganic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Geochemistry & Mineralogy (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
The invention discloses a modified diatomite loaded ferrous sulfide composite material, and a preparation method and application thereof, and relates to the technical field of industrial wastewater treatment. The preparation method of the modified diatomite loaded ferrous sulfide composite material is characterized in that the diatomite loaded ferrous sulfide modified by oxalic acid pickling is used for obtaining the modified diatomite loaded ferrous sulfide composite material with good dispersibility, hexavalent chromium in industrial wastewater can be effectively adsorbed and reduced, and the adsorption and reduction rate is high, the adsorption capacity is large, and the chemical stability is high. The modified diatomite loaded ferrous sulfide composite material is particularly suitable for adsorbing and reducing high-toxicity hexavalent chromium in water, can effectively adsorb and reduce hexavalent chromium within the pH range of 3.0-9.0, and can reduce the concentration of hexavalent chromium to 0.047mg/L after being added into the water containing 50mg/L hexavalent chromium for reaction for 90min, and the removal rate reaches 99.91%.
Description
Technical Field
The invention relates to the technical field of industrial wastewater treatment, in particular to a modified diatomite loaded ferrous sulfide composite material, and a preparation method and application thereof.
Background
Hexavalent chromium is a soluble heavy metal ion with high toxicity and high mobility, is easily absorbed by human bodies, causes various health problems, and mainly exists in the form of HCrO 4 - or CrO 4 2- in water bodies. With the development of industries such as electroplating, dye, leather and steel manufacturing, metallic chromium and its compounds are widely used as raw materials in these industries, and the large amount of discharged chromium-containing waste residues and wastewater cause surface water to be polluted by chromium to different extents, so that it is highly demanded to find a method capable of effectively treating hexavalent chromium-containing wastewater.
There are many techniques that have been successfully applied to water pollution treatment, among which adsorption/reduction is one of the most widely used methods. Adsorbents (e.g., activated carbon, clay minerals, metal oxides, etc.) are used in the treatment of chromium-containing wastewater, wherein a portion of the adsorbent contains reducing properties that reduce hexavalent chromium in the water. Ferrous sulfide is considered to be an excellent adsorbent for removing hexavalent chromium due to its two reducing ions. However, ferrous sulfide has magnetism, is easy to agglomerate, reduces the specific surface area and the heterogeneous contact probability of the ferrous sulfide, so that the dispersion degree of the ferrous sulfide is improved, and the simplification of the synthesis process is the focus of current research. Based on the goal of reducing highly toxic, highly mobile hexavalent chromium to low toxic, low mobile trivalent chromium, dispersing ferrous sulfide on a support material is currently a viable method.
The prior art discloses a preparation method of an alumina-supported nano ferrous sulfide composite material, which uses alumina as a carrier, and covers nano ferrous sulfide particles on the surface of the alumina through heating and stirring to obtain the alumina-supported nano ferrous sulfide composite material, so that the problem that the existing nano ferrous sulfide is easy to agglomerate in the wastewater treatment process is solved, but the adsorption capacity and adsorption efficiency of the composite material are low and need to be further improved.
Disclosure of Invention
The invention aims to overcome the defects and the shortcomings of the prior art, and provides a preparation method of a modified diatomite loaded ferrous sulfide composite material, which realizes the effects of high chemical stability and large adsorption capacity while realizing high adsorption reduction rate by loading ferrous sulfide on diatomite with a modified porous structure, and can effectively adsorb and reduce hexavalent chromium in wastewater within a wide pH range of 3.0-9.0.
The invention further aims to provide a modified diatomite loaded ferrous sulfide composite material.
The invention further aims at providing an application of the modified diatomite loaded ferrous sulfide composite material in removing heavy metal ions in wastewater.
The above object of the present invention is achieved by the following technical scheme:
a preparation method of a modified diatomite loaded ferrous sulfide composite material comprises the following steps:
S1, adding oxalic acid into diatomite suspension to obtain mixed suspension, carrying out solid-liquid separation, and drying to obtain modified diatomite, wherein the concentration of oxalic acid in the mixed suspension is not lower than 3mmol/L, and the concentration of diatomite is 5-15 mg/mL;
S2, adding the modified diatomite in the S1 into ferrous sulfide suspension, stirring under an anaerobic condition, performing solid-liquid separation, and performing aftertreatment to obtain the modified diatomite loaded ferrous sulfide composite material, wherein the mass ratio of the ferrous sulfide to the modified diatomite is 1:1-3:1.
The following are to be described:
The oxalic acid solution in the step S1 is a modifier of diatomite, hydroxyl groups on the diatomite are protonated through acid leaching, so that the surface of the diatomite is positively charged, hexavalent chromium ions in the wastewater in the form of anion groups HCrO 4 - or CrO 4 2- are adsorbed, the specific surface area of the diatomite modified by oxalic acid is improved, the pore structure such as the number and the pore diameter of pores are improved, and the loading capacity of the diatomite to ferrous sulfide is further improved.
The diatomite has stable property, and the modified diatomite loaded ferrous sulfide can improve the chemical stability of the composite material, so that the prepared modified diatomite loaded ferrous sulfide composite material can effectively adsorb and reduce heavy metal ions in wastewater within a wide pH range of 3.0-9.0.
In addition, oxalic acid is a reducing binary weak acid, contains two carboxyl groups, and can effectively adsorb heavy metal ions by utilizing the coordination bond formed by the combination of unbound electrons of oxygen in the carboxyl groups and empty orbits of metal ions, so that oxalic acid is used for modifying diatomite, and the method has remarkable advantages in the adsorption and reduction of the heavy metal ions in subsequent wastewater. However, when the oxalic acid concentration is too low, poor modification of diatomite can occur, namely, the protonation degree of the diatomite is low, so that the adsorption reduction rate of the diatomite in wastewater treatment is reduced; the main component of the diatomite is silica, namely acid oxide, is insoluble in acid, so that the structure of the diatomite is not influenced when the concentration of oxalic acid is increased, and the oxalic acid has no further improvement effect on the diatomite when the concentration is too high.
In the step S1, the concentration of diatomite is required to be reasonably controlled, when the concentration of diatomite is too high, the dispersity of the suspension is reduced, so that undispersed diatomite cannot be completely leached when the diatomite is subjected to acid leaching modification, the modification effect is poor, and when the concentration of diatomite is too low, the diatomite in the suspension has few solid particles, so that the subsequent solid-liquid separation is not facilitated.
In the S2 step, the mass ratio of ferrous sulfide to modified diatomite can influence the dispersion and load of ferrous sulfide, and when the mass ratio is too small, namely the proportion of ferrous sulfide is small, the ferrous sulfide loaded by the modified diatomite is less, so that the adsorption reduction rate is low when wastewater treatment is carried out; when the proportion of ferrous sulfide is too large, namely the mass ratio is too large, because ferrous sulfide has sub-magnetism, excessive ferrous sulfide can cause agglomeration of ferrous sulfide particles, and the adsorption reduction rate in the wastewater treatment process can be reduced.
In addition, since ferrous sulfide itself has strong reducibility and is easily oxidized, stirring under an anaerobic condition is required in the step S2 to avoid oxidation of ferrous sulfide.
The modified diatomite suspension in the step S1 of the invention can be prepared by the following modes:
adding diatomite into deionized water to prepare suspension, and dispersing by using an ultrasonic dispersing instrument.
The diatomite surface has abundant hydroxyl groups, and the hydroxyl groups can adsorb metal cations such as calcium, magnesium and the like in tap water, so deionized water is used for preparing diatomite suspension, and the phenomenon that the protonation effect of the hydroxyl groups in acid leaching modified diatomite is influenced due to the fact that the metal cations such as calcium, magnesium and the like in water form precipitates on the diatomite surface is avoided.
The solid-liquid separation mode in the step S1 can be suction filtration.
The ferrous sulfide suspension in step S2 of the present invention may be prepared by:
ferrous salt and sulfide salt are added into deionized water filled with nitrogen, and the mixture is stirred under the condition of constant temperature water bath after being sealed.
Wherein the molar ratio of iron to sulfur element is 1:1-1:3, the water bath temperature is 50-80 ℃, and the stirring time is 1-2 h. The ferrous salt is ferrous sulfate (FeSO 4) or ferrous sulfate heptahydrate (FeSO 4·7H2 O), and the sulfide salt is sodium sulfide nonahydrate (Na 2S·9H2 O) or sodium sulfide (Na 2 S).
The post-treatment in the step S2 of the invention comprises the following operation steps:
The solid obtained after the solid-liquid separation was washed with oxygen-free water and dried under vacuum freezing conditions. Wherein, the solid-liquid separation can adopt a centrifugal or natural sedimentation mode at the rotating speed of 3000-8000 rpm, and the anaerobic water is deionized water filled with nitrogen.
In the preparation method of the modified diatomite loaded ferrous sulfide composite material, the condition which is not illustrated is the common condition in the prior art.
Preferably, the concentration of diatomite in the mixed suspension of the step S1 is 8-11 mg/mL, more preferably 10mg/mL.
Preferably, the concentration of oxalic acid in the mixed suspension of the step S1 is 5 to 15mmol/L, more preferably 5 to 10mmol/L, and still more preferably 5mmol/L.
Preferably, the mass ratio of the ferrous sulfide to the modified diatomite in the step S2 is 1:1-2:1, and more preferably 1:1.
Preferably, the stirring time in the step S2 is 0.5-2 h.
And S2, the stirring time in the step also affects the dispersion degree of ferrous sulfide, when the stirring time is too low, the ferrous sulfide and the modified diatomite cannot be fully mixed, so that the modified diatomite has poor limiting effect on agglomeration of the ferrous sulfide, and the ferrous sulfide cannot be uniformly dispersed and loaded on the modified diatomite, so that the adsorption reduction rate of the modified diatomite is further affected.
The preparation method of the modified diatomite loaded ferrous sulfide composite material is simple, the high-temperature roasting and other processes are not needed, the used raw materials are cheap and easy to obtain, and the prepared modified diatomite loaded ferrous sulfide composite material has the characteristics of good dispersibility, high adsorption and reduction rate, large adsorption capacity, high chemical stability and the like.
The invention also specifically protects a modified diatomite loaded ferrous sulfide composite material, which is prepared by the preparation method.
The modified diatomite loaded ferrous sulfide composite material disclosed by the invention has the advantages that the modified diatomite has rich pore structures, the loading of ferrous sulfide is realized, the surface of the modified diatomite is positively charged, the electrostatic force repulsive interaction of the modified diatomite further disperses ferrous sulfide particles, the agglomeration of the ferrous sulfide particles in the reaction process of adsorbing heavy metal ions in wastewater is effectively prevented, and the adsorption capacity and the adsorption reduction rate are improved. When hexavalent chromium in wastewater is treated, the hexavalent chromium mainly exists in the wastewater in the form of anion groups HCrO 4 - or CrO 4 2-, so that the positive charge on the surface of the modified diatomite can also promote the adsorption effect on the hexavalent chromium and accelerate the adsorption reduction rate.
The invention particularly protects the application of the modified diatomite loaded ferrous sulfide composite material in removing heavy metal ions in wastewater.
Preferably, the heavy metal ion in the wastewater is hexavalent chromium.
More preferably, the hexavalent chromium is present in the form of HCrO 4 - or CrO 4 2-.
The modified diatomite loaded ferrous sulfide composite material is suitable for wastewater with the pH value of 3.0-9.0, and more preferably, the initial pH value of the wastewater is 3.0-5.0.
Compared with the prior art, the invention has the beneficial effects that:
The invention provides a preparation method of a modified diatomite loaded ferrous sulfide composite material, which can effectively prevent agglomeration of ferrous sulfide particles and can realize the effects of large adsorption capacity and high adsorption reduction rate in wastewater treatment. In addition, the modified diatomite loaded ferrous sulfide composite material can well remove hexavalent chromium in the wastewater within the pH range of 3.0-9.0, and the strong anion removing capability also enables the interference degree of anions on the composite material to be low, so that the chemical stability of the composite material in removing heavy metal ions in the wastewater is improved.
The modified diatomite loaded ferrous sulfide composite material is particularly suitable for adsorbing and reducing hexavalent chromium in water, the concentration of hexavalent chromium is reduced to 0.306mg/L after the hexavalent chromium reacts for 30min in the water containing 50mg/L hexavalent chromium, the concentration of hexavalent chromium is reduced to 0.047mg/L after the hexavalent chromium reacts for 90min, and the removal rate reaches 99.91%; the maximum adsorption capacity reached after 90min of reaction was 135.9mg/g, corresponding to a molar concentration of 2.614mmol/g.
In addition, the modified diatomite loaded ferrous sulfide composite material disclosed by the invention is used for chemically adsorbing hexavalent chromium, the hexavalent chromium exists in a chromium hydroxide form after being adsorbed and reduced to trivalent chromium, and when the initial pH value of a water body is 3.0-9.0, the generated chromium hydroxide after the reaction is insoluble, so that the trivalent chromium can be fixed on the material, and desorption or migration cannot occur.
Drawings
FIG. 1 is a scanning electron microscope image of a modified diatomaceous earth-supported ferrous sulfide composite of example 1;
FIG. 2 is an elemental mapping analysis chart of the modified diatomite-supported ferrous sulfide composite material of example 1;
FIG. 3 is a graph showing the adsorption reduction capacity of a composite material of ferrous sulfide, modified diatomite, and different mass ratios of ferrous sulfide to modified diatomite for hexavalent chromium;
FIG. 4 is a graph of the ability of the modified diatomaceous earth loaded ferrous sulfide composite of example 1 to remove hexavalent chromium in the presence of anions;
FIG. 5 is a graph of the removal capacity of the modified diatomaceous earth loaded ferrous sulfide composite of example 1 for hexavalent chromium at various initial concentrations;
FIG. 6 is a graph comparing the stability of the modified diatomaceous earth loaded ferrous sulfide composite material of example 1 and ferrous sulfide.
Detailed Description
The invention will be further described with reference to the following specific embodiments, but the examples are not intended to limit the invention in any way. Raw materials reagents used in the examples of the present invention are conventionally purchased raw materials reagents unless otherwise specified.
Example 1
The preparation method of the modified diatomite loaded ferrous sulfide composite material comprises the following steps:
S1, adding 2.0g of diatomite into 200mL of deionized water to prepare a suspension, and performing ultrasonic dispersion for 30min to obtain a diatomite suspension;
S2, adding oxalic acid into diatomite suspension to obtain a mixed solution, magnetically stirring, and then carrying out suction filtration on the suspension, drying the obtained wet solid in an oven at 80 ℃ for 1h, and grinding the dried solid to obtain a product, namely modified diatomite, wherein the concentration of oxalic acid in the mixed solution is 5mmol/L, and the concentration of diatomite is 10mg/mL;
S3, adding 1.58g of ferrous sulfate heptahydrate and 2.72g of sodium sulfide nonahydrate into 100mL of deionized water filled with nitrogen for 30min, sealing, and magnetically stirring at a rotating speed of 800rpm under a constant-temperature water bath at 60 ℃ for 1h to obtain ferrous sulfide suspension;
S4, adding the modified diatomite into a ferrous sulfide suspension, wherein the mass ratio of the ferrous sulfide to the modified diatomite is 1:1, sealing, magnetically stirring for 30min, centrifuging the suspension at 6000 rpm for 3min, flushing with deionized water which is aerated with nitrogen and deoxidized, freezing, vacuum drying, and grinding to obtain the modified diatomite loaded ferrous sulfide composite material (the ferrous sulfide loading amount is 14.7 percent through detection).
Examples 2 to 12 and comparative examples 1 to 5
The preparation method of the modified diatomite loaded ferrous sulfide composite material is the same as in example 1, and the difference is shown in Table 1.
TABLE 1 recipe parameters of modified diatomaceous earth-supported ferrous sulfide composite materials of examples 1 to 12 and comparative examples 1 to 5
Performance testing
The adsorption capacity of the modified diatomite loaded ferrous sulfide composite material to hexavalent chromium is tested by the following method:
the Langmuir isotherm model assumes that there is a monolayer adsorption that occurs at a specific homogeneous site within the biological adsorbent. The linear Langmuir isotherm model is as follows:
wherein C e (mg/L) is the equilibrium concentration, q e (mg/g) is the adsorption capacity, q max and K L (L/mg) are Langmuir equilibrium constants, and q max (mg/g) is the theoretical maximum adsorption capacity.
See table 2 and fig. 5 for specific test results.
TABLE 2 test results of theoretical maximum adsorption capacity of composite materials
According to the above formula and the data in table 1, the theoretical maximum adsorption capacity q max of the composite material (the mass ratio of ferrous sulfide to modified diatomite is 1:1) is: 135.9mg/g. Wherein R 2 is 0.9511, the linear model fitting can be considered to be successful, and the theoretical maximum adsorption has credibility.
The adsorption reduction rate of hexavalent chromium is represented by the residual concentration of hexavalent chromium, and the specific method is as follows:
Adding 50mg of modified diatomite loaded ferrous sulfide composite material into 0.05L wastewater with the initial concentration of Cr (VI) of 50.0mg/L, dispersing the composite material in the solution for reaction by oscillation at room temperature, filtering the solution by a filter membrane with the wavelength of 0.45 mu m after the reaction is carried out for 3/5/10/20/30/60/90min, measuring the absorbance of hexavalent chromium in the supernatant by an ultraviolet spectrophotometer at the wavelength of 540nm, and converting the absorbance into the concentration by a standard curve with the R 2 of more than 0.999 to obtain the residual concentration of hexavalent chromium, wherein the residual concentration of hexavalent chromium after the reaction is carried out for 90min is shown in table 3.
The chemical stability of the composite material was tested by the following steps:
and (3) blowing nitrogen to the prepared ferrous sulfide and composite material (the mass ratio of the ferrous sulfide to the modified diatomite is 1:1), placing the materials in a dryer for 0, 7 and 15 days, and taking the materials for hexavalent chromium adsorption reaction to determine the chemical stability of the materials.
See fig. 6 for specific test results.
TABLE 3 test results of modified diatomite loaded ferrous sulfide composite Material Performance
As can be seen from the results in table 3, when the concentration of the diatomite suspension is high, the diatomite modification effect is poor under the same concentration of acid leaching conditions, which is characterized by a small adsorption capacity and a high residual concentration of hexavalent chromium; when the oxalic acid concentration was increased from 10mmol/L to 15mmol/L, the modifying effect was not further enhanced. In addition, when the mass ratio of ferrous sulfide to modified diatomite is increased, the effect of treating wastewater is not always enhanced. When the mass ratio of ferrous sulfide to modified diatomite is 1:1, the residual concentration of hexavalent chromium after reacting for 90min is 0.047mg/L; when the mass ratio of ferrous sulfide to modified diatomite is 3:1, the residual concentration of hexavalent chromium after 90min of reaction is 0.256mg/L. Namely, when the mass ratio of ferrous sulfide to modified diatomaceous earth is further increased, the adsorption reduction rate is lowered, and when the mass ratio of ferrous sulfide to modified diatomaceous earth is less than 1:1 (comparative example 4), the adsorption capacity for hexavalent chromium is significantly lowered. Moreover, after the diatomite is modified by using hydrochloric acid or sulfuric acid, the adsorption reduction rate and the adsorption capacity of the obtained composite material are not as great as those of the composite material obtained by using oxalic acid.
FIG. 1 is a scanning electron microscope image of the modified diatomaceous earth-supported ferrous sulfide composite material prepared in example 1. As can be seen from the pictures, the original diatomite has a disc-shaped porous structure (fig. 1 (a)), but the surface is relatively smooth and lacks rich adsorption sites, while the surface morphology of the diatomite modified by oxalic acid (fig. 1 (b)) is obviously improved, the adsorption sites are more rich, the pore structure is also obviously improved, the number of pores is increased, the pore diameter is small, namely the whole specific surface area is increased, and the loading and the dispersion of ferrous sulfide particles are facilitated. Fig. 1 (c) shows the surface morphology of the composite material with a rough lamellar surface structure, further illustrating the increased specific surface area. The surface of the composite material adsorbs part of diatomite scraps, and the surface of the diatomite scraps is negatively charged, which means that after the diatomite scraps are subjected to oxalic acid leaching modification, hydroxyl groups on the surface of the diatomite are protonated and positively charged, so that heavy metal ions in the form of anion groups in the wastewater can be effectively adsorbed. Fig. 1 (d) shows the surface morphology of the composite material after hexavalent chromium is adsorbed, and it can be seen that solid substances are adsorbed on the surface of the composite material, indicating that the solid substances generated in the reaction are precipitated on the surface of the composite material.
The element mapping analysis chart of the modified diatomite loaded ferrous sulfide composite material in example 1 is shown in fig. 2, and it can be seen that iron and sulfur are main elements on the surface of the modified diatomite and are uniformly distributed on the surface of the modified diatomite, which indicates that the modified diatomite is successfully loaded with ferrous sulfide particles and is uniformly dispersed.
Fig. 3 is a graph showing the adsorption and reduction capacities of the composite materials of the ferrous sulfide of comparative example 4, the modified diatomite of comparative example 5 and the preparation method with different mass ratios of the ferrous sulfide to the modified diatomite of examples 1, 5 and 6 on hexavalent chromium, and specifically shows the adsorption performance of the ferrous sulfide to the modified diatomite with the mass ratios of 1:1, 2:1, 3:1, pure ferrous sulfide and pure modified diatomite on hexavalent chromium. As can be seen from FIG. 3 (a), the other samples, except for the modified diatomaceous earth, have good removal ability for hexavalent chromium. In 4 samples with the mass ratio of ferrous sulfide to modified diatomite of 1:1, 2:1, 3:1 and pure ferrous sulfide, after the reaction is carried out for 90 minutes, the residual concentration of hexavalent chromium is respectively 0.047mg/L, 0.091mg/L, 0.256mg/L and 0.268mg/L, which shows that the adsorption reduction rate of the modified diatomite loaded ferrous sulfide composite material to hexavalent chromium in wastewater is improved, and the best is achieved when the mass ratio of ferrous sulfide to modified diatomite is 1:1. Fig. 3 (b) shows the removal effect of the composite material with the mass ratio of ferrous sulfide to modified diatomite of 1:1 on hexavalent chromium, and it can be seen that the residual concentration of hexavalent chromium decreases with increasing amount, i.e. the removal effect increases with increasing amount. In addition, FIG. 3 (c) shows that the modified diatomite loaded ferrous sulfide composite material has the best hexavalent chromium removal effect at initial pH values of 3.0 and 5.0, and the concentration of hexavalent chromium after 90 minutes of reaction is kept below 1.0 mg/L. It can be seen that the removal effect of the composite material under acidic conditions is better than that under alkaline and neutral conditions. This is because more H + reacts with FeS under acidic conditions, which causes the ferrous sulfide to dissolve more rapidly, producing reducing ions Fe 2+ and S 2-, further accelerating the reduction of hexavalent chromium, which also suggests that the positively charged surface of the modified diatomaceous earth is beneficial for accelerating the adsorption reduction rate of hexavalent chromium. In fig. 3 (d), the pH change chart during the reaction process is shown in fig. 3 (d), when the pH is 3.0-9.0, the pH of the solution is 6.8-10.5 after 90min of reaction, and the K sp of the chromium hydroxide is 6.3×10 -31, the content of the dissolved chromium hydroxide in the solution can be calculated according to the pH range after the reaction, which is within 2.51×10 -9～2.00×10-20 mol/L, and is lower than 1×10 -6, and the obtained modified diatomite loaded ferrous sulfide composite material can be regarded as complete precipitation, which shows that the obtained trivalent chromium exists in the form of chromium hydroxide and is insoluble after the adsorption reduction of hexavalent chromium, and the trivalent chromium can be fixed on the material without desorption or migration.
FIG. 4 is a graph showing the ability of the modified diatomaceous earth-supported ferrous sulfide composite of example 1 to remove hexavalent chromium in the presence of anions, showing that when Cl-, SO 4 2-、CO3 2- at a concentration of 1mmol/L coexist with a hexavalent chromium solution, the concentrations of hexavalent chromium in the reacted solution are 0.953mg/L, 0.401mg/L and 0.312mg/L, respectively. Therefore, when hexavalent chromium and Cl -、SO4 2-、CO3 2- groups coexist, cr (VI) still has good removal effect after 90 minutes of reaction, namely the modified diatomite loaded ferrous sulfide composite material is less influenced by anions in a water body and has good stability.
Fig. 6 is a comparison of the stability of the modified diatomite loaded ferrous sulfide composite material and the stability of ferrous sulfide of example 1, and it can be seen that the modified diatomite loaded ferrous sulfide composite material prepared by the invention has good stability, and the removal rate of hexavalent chromium can still reach more than 90% after the modified diatomite loaded ferrous sulfide composite material is placed for 15 days.
It should be noted that, although the test results of the corresponding scanning electron microscope image and the element mapping analysis image are not described in the other embodiments, the related performances are equivalent.
It is to be understood that the above examples of the present invention are provided by way of illustration only and not by way of limitation of the embodiments of the present invention. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.
Claims (4)
1. The application of the modified diatomite loaded ferrous sulfide composite material in removing heavy metal ions in wastewater is characterized in that the heavy metal ions in the wastewater are hexavalent chromium, and the initial pH value of the wastewater is 3.0-5.0;
the preparation method of the modified diatomite loaded ferrous sulfide composite material comprises the following steps:
s1, adding oxalic acid into diatomite suspension to obtain mixed suspension, carrying out solid-liquid separation, and drying to obtain modified diatomite, wherein the concentration of oxalic acid in the mixed suspension is 5-10 mmol/L, and the concentration of diatomite is 5-15 mg/mL;
S2, adding the modified diatomite in the S1 into ferrous sulfide suspension, stirring under an anaerobic condition, performing solid-liquid separation, and performing aftertreatment to obtain the modified diatomite loaded ferrous sulfide composite material, wherein the mass ratio of the ferrous sulfide to the modified diatomite is 1:1-2:1.
2. The use according to claim 1, wherein the concentration of diatomite in the mixed suspension of the step S1 in the preparation method of the modified diatomite-supported ferrous sulfide composite material is 8-11 mg/mL.
3. The use of claim 1, wherein the stirring time in step S2 is 0.5 to 2 hours in the preparation method of the modified diatomite-supported ferrous sulfide composite material.
4. The use according to claim 1 wherein said hexavalent chromium is present in the form of HCrO 4 - or CrO 4 2- .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211003305.9A CN115400722B (en) | 2022-08-19 | 2022-08-19 | Modified diatomite loaded ferrous sulfide composite material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211003305.9A CN115400722B (en) | 2022-08-19 | 2022-08-19 | Modified diatomite loaded ferrous sulfide composite material and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115400722A CN115400722A (en) | 2022-11-29 |
| CN115400722B true CN115400722B (en) | 2024-04-26 |
Family
ID=84161456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211003305.9A Active CN115400722B (en) | 2022-08-19 | 2022-08-19 | Modified diatomite loaded ferrous sulfide composite material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115400722B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2345930A1 (en) * | 2000-08-29 | 2002-02-28 | Eric L. Winchester | Removing chromium from water |
| CN110040785A (en) * | 2019-04-04 | 2019-07-23 | 河海大学 | A kind of titanate radical nanopipe composite material and preparation method and application loading ferrous sulfide |
-
2022
- 2022-08-19 CN CN202211003305.9A patent/CN115400722B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2345930A1 (en) * | 2000-08-29 | 2002-02-28 | Eric L. Winchester | Removing chromium from water |
| CN110040785A (en) * | 2019-04-04 | 2019-07-23 | 河海大学 | A kind of titanate radical nanopipe composite material and preparation method and application loading ferrous sulfide |
Non-Patent Citations (1)
| Title |
|---|
| Adsorption characteristics of mercury (II) ions from aqueous solution onto chitosan-coated diatomite;Necmettin Caner等;Industrial & Engineering Chemistry Research;第1-39页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115400722A (en) | 2022-11-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wu et al. | Green synthesis of reusable super-paramagnetic diatomite for aqueous nickel (II) removal | |
| WO2005102942A1 (en) | Reducing water purification material, method for producing reducing water purification material, method for treating wastewater, and wastewater treatment apparatus | |
| CN114797783B (en) | Adsorbent for selectively removing Cr (VI) and preparation method and application thereof | |
| CN111135798B (en) | Rust material and preparation method and application thereof | |
| CN114100634B (en) | Preparation method, product and application of magnetic multi-component iron-carbon composite Fenton-like catalyst | |
| CN113385138A (en) | Preparation method and application of Schneider mineral | |
| CN113546606A (en) | Preparation and application of lignin-doped metal organic framework-derived carbon-iron composite material | |
| CN114425305B (en) | Mercury adsorption material, preparation method thereof and application thereof in flue gas or solution mercury removal | |
| CN114452936A (en) | Preparation method and application of fenton sludge-based magnetic adsorbent | |
| CN115400722B (en) | Modified diatomite loaded ferrous sulfide composite material and preparation method and application thereof | |
| CN114849659B (en) | Method for removing heavy metal cadmium and phosphate in water by using lanthanum-iron loaded chitosan microsphere adsorbent | |
| CN111282541A (en) | Arsenic removal composite material and preparation method thereof | |
| KR101481465B1 (en) | Method for manufacturing iron sulfide coated Porous supporter and iron sulfide coated Porous supporter manufactured by samemethod | |
| JP4936559B2 (en) | Arsenic remover | |
| CN114367271B (en) | Load type MnO X Preparation method of @ NiCo-MOF composite material | |
| CN115090275A (en) | Nano composite material for sewage treatment and application thereof | |
| CN113289570B (en) | Arsenic adsorbing material and preparation method and application thereof | |
| CN114749139A (en) | Amorphous nano zero-valent iron, preparation method thereof and application of amorphous nano zero-valent iron in removing antimony in water body | |
| CN113121758B (en) | Nano-iron oxyhydroxide gel composite material and preparation method and application thereof | |
| CN113996271A (en) | Bimetal modified carbon nanotube adsorbent and preparation method and application thereof | |
| CN112934170A (en) | Magnetic nano-ore composite material for efficiently removing thallium, and preparation method and application thereof | |
| TWI666172B (en) | Nano iron-alumina composite material, and preparation method and application thereof | |
| CN112934178A (en) | Nanocomposite and method for efficiently removing arsenic in wastewater | |
| Denizli et al. | Adsorption of mercury (II) ions on Procion Blue MX-3G-attached magnetic poly (vinyl alcohol) gel beads | |
| Yu et al. | Removal of Cr (vi) in wastewater by Fe–Mn oxide loaded sludge biochar |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |