CN110921813A - Application of modified mussel shell filler in biological aerated filter for sewage treatment - Google Patents
Application of modified mussel shell filler in biological aerated filter for sewage treatment Download PDFInfo
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- C02F3/00—Biological treatment of water, waste water, or sewage
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- C02F3/06—Aerobic processes using submerged filters
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- C02F3/02—Aerobic processes
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- C02F3/107—Inorganic materials, e.g. sand, silicates
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
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- C02F2101/105—Phosphorus compounds
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- C02F2101/16—Nitrogen compounds, e.g. ammonia
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- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
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- 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
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Abstract
The invention provides a preparation method of a modified mussel shell filler, which comprises the following steps: s1, preparing magnetic nanoparticles; s2, pretreatment of mussel shells: cleaning mussel shell, oven drying, carbonizing at high temperature under nitrogen protection, and grinding; s3, preparing the magnetic mussel shell: respectively adding magnetic nanoparticles and ammonia water into water, heating, dropwise adding a silane coupling agent, reacting at constant temperature under the protection of nitrogen, adding mussel shell powder, continuing to react, cooling to room temperature, washing a product with deionized water for three times, and separating by using a magnet for later use; s4, preparing the modified mussel shell filler: adding magnetic mussel shell into water, stirring, adding organic acid, reacting, washing with water and ethanol for three times, magnetically separating, drying, and grinding to obtain modified mussel shell filler. The modified mussel shell filler has good purification performance on sewage in the biological aerated filter, and has the advantages of simple modification conditions, convenient operation and strong operability.
Description
Technical Field
The invention relates to the technical field of sewage treatment, in particular to a modified mussel shell filler, a preparation method thereof and application of the modified mussel shell filler in sewage treatment in an aeration biological filter.
Background
With the development of science and technology, the water consumption of industry and living is increasing day by day, but the water resource is limited, so the sewage recycling is the very necessary process, can alleviate water pressure to a certain extent. In the field of sewage treatment, in addition to the conventional physical methods including adsorption, air flotation separation, electromagnetic effect, etc., there are also physical-chemical methods and chemical oxidation methods. However, the above method cannot achieve good effect, so that the biofilm method is rapidly developed to improve the water treatment quality, and the main principle is that microorganisms are attached to the surface of a carrier to grow into a film shape, organic pollutants in sewage are adsorbed, stabilized and oxidized by the microorganisms in the process that the sewage flows through the surface of the carrier and contacts with the biofilm, and are finally converted into H2O、CO2、NH3And microbial cell material to purify sewage. The biofilm process is mainly used for secondary biological treatment in sewage at present, and in the biofilm process treatment process, a biofilter is the most representative structural form, and can be divided into an anaerobic biofilter and an aerobic biofilter according to whether the biofilter needs to supply oxygen during operation, and the anaerobic biofilter has the advantages that: the organic matter removing efficiency is high, the effluent suspended matter SS is low, the operation is stable, the management is simple and convenient, and the anaerobic biofilter has the main problems that the water inlet distribution is not easy to be uniform and the filter material is easy to block. In the aerobic biofilter, the aerobic biofilter is also called as a common biofilter according to the structure of the filter pool, the oxygen supply mode and whether a back flushing system is provided or not, and the common biofilter has the advantage of high removal rate of Biochemical Oxygen Demand (BOD).
A Biological Aerated Filter (BAF) is a novel technology for treating sewage by using a filler as a biofilm carrier through functions of biodegradation, adsorption and the like. The filler not only determines the initial construction and cost of the BAF process, but also is a key factor influencing the BAF treatment effect. Static tests show that the shells can remove phosphorus from water by chemical action under acidic conditions. The anti-phosphorus sewage treatment method is characterized in that the anti-phosphorus sewage treatment method is used for removing phosphorus in sewage. Hydrolytic acidification is used as a pretreatment process, and can reduce the treatment cost and improve the treatment efficiency by combining with other processes. Many researches on the aspect are carried out, such as the treatment of domestic sewage by using a hydrolysis acidification and suspension filter material BAF integrated device, the treatment of campus domestic sewage by using hydrolysis acidification integrated D-A2O and the treatment of urban domestic sewage by using hydrolysis acidification and biological contact oxidation processes, and good treatment effects are obtained. At present, researches on the application of modified mussel shells as biological aerated filter packing for treating domestic sewage are rarely reported.
Disclosure of Invention
The invention provides a modified mussel shell filler and a preparation method thereof and application of a biological aerated filter to sewage treatment, and aims to provide a modified mussel shell filler and a preparation method thereof and application of a biological aerated filter to sewage treatment2+Dissolve out, organic acid remains on modified mussel shell filler surface simultaneously, easily breeds anaerobic bacteria, through aeration equipment entering sewage, total phosphorus in the high-efficient removal sewage consumes COD and ammonia nitrogen waste in the sewage, plays the effect of purifying sewage.
The invention provides a preparation method of a modified mussel shell filler, which comprises the following steps:
s1, preparation of magnetic nanoparticles: heating ferric chloride hexahydrate and ferrous chloride tetrahydrate to reaction temperature in nitrogen atmosphere, dropwise adding ammonia water, reacting at constant temperature for 2-5h under the protection of nitrogen, cooling to room temperature, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating with magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding magnetic nanoparticles and ammonia water into deionized water, heating to reaction temperature, dropwise adding a silane coupling agent, reacting at constant temperature for 3-6h under the protection of nitrogen, adding mussel shell powder, continuing to react for 2-3h, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and separating by using a magnet for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 20-30min, adding organic acid, stirring at room temperature for 6-12 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 6-9 hr, and grinding to obtain modified mussel shell filler.
As a further improvement of the invention, in the step S1, the reaction temperature is 50-60 ℃, and the mass ratio of the ferric chloride hexahydrate to the ferrous chloride tetrahydrate is 1: (2-3); the mass fraction of the ammonia water is 20-24%; the mass volume ratio of the ferric chloride hexahydrate to the ammonia water is 1: (10-30).
As a further improvement of the invention, the mass ratio of the magnetic nanoparticles, the silane coupling agent and the mussel shell powder in the step S3 is 2 (0.01-0.03): 10; the mass fraction of the ammonia water is 20-24%; the mass-volume ratio of the magnetic nanoparticles to the ammonia water is 1: (10-20).
As a further improvement of the present invention, in step S4, the organic acid is selected from one or more of citric acid, acetic acid, malic acid, formic acid, malonic acid, stearic acid, succinic acid, tartaric acid and ascorbic acid; the mass ratio of the magnetic mussel shell to the organic acid is 10: (2-5).
As a further improvement of the invention, the silane coupling agent is an epoxy alkyl silane coupling agent, and is selected from one or a mixture of KH560, KH791 and Nanda-73.
The invention further protects the modified mussel shell filler prepared by the preparation method.
The invention further protects the application of the modified mussel shell filler in sewage treatment in a biological aerated filter.
As a further improvement of the invention, water enters the bottom of the filter tank from a water inlet tank, air and water are in the same direction from bottom to top, treated water flows out from the top, a certain amount of activated sludge is added as sludge seeds when the reactor is started, when the sludge settlement ratio reaches 30%, modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration rate is 0.2-0.4L/min.
As a further improvement of the present invention, the preparation method of the magnetic nanoparticles comprises: dissolving cobalt chloride hexahydrate in a book in nitrogen atmosphere, then dropwise adding ammonia water, slowly adding sodium borohydride under the protection of nitrogen, reacting for 1-2h, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use.
As a further improvement of the invention, the mass ratio of the cobalt chloride hexahydrate to the sodium borohydride is (70-100): 1; the mass fraction of the ammonia water is 20-24%; the mass ratio of the cobalt chloride hexahydrate to the ammonia water is 1: (10-20).
The invention has the following beneficial effects:
according to the method, the carbonized mussel shell is connected with the mussel shell powder carbonized at high temperature through the silane coupling agent, so that the prepared mussel shell powder is magnetic, is convenient for magnetic separation, avoids complex steps such as filtering, centrifuging and the like on the adsorbent after the dye is removed, and simplifies the operation;
CaCO of shell3The components are gradually dissolved in an acidic environment and Ca is released2+These Ca2+Can react with PO under certain conditions4 3-The magnetized mussel shell powder is treated by organic acid to form Ca2+Dissolving out, meanwhile, organic acid is remained on the surface of the modified mussel shell filler, anaerobic bacteria are easy to breed, and the organic acid enters sewage through an aeration device, so that the total phosphorus in the sewage is efficiently removed, COD (chemical oxygen demand) and ammonia nitrogen waste in the sewage are consumed, and the sewage purification effect is achieved;
the mussel shell powder is modified by adopting the epoxy hydrocarbon silane coupling agent, and the mussel shell powder contains more carboxyl groups on calcium carbonate, so that the efficient coupling effect is achieved, the coupling efficiency is further improved, and the using amount of the coupling agent is reduced;
the modified mussel shell filler has good purification performance on sewage in the biological aerated filter, and has the advantages of simple modification conditions, convenient operation and strong operability. The waste mussel shells are used as raw materials, so that the method has good environmental benefits and can generate good economic benefits.
Drawings
FIG. 1 is a graph showing comparison of the detection of adsorption rates of total phosphorus, COD and ammonia nitrogen in examples 4 and 5 and examples 8 and 9 of the present invention;
FIG. 2 is a graph showing comparison between the detection of the removal rate of the adsorbent in examples 4 and 5 and examples 8 and 9 of the present invention;
FIG. 3 is a graph comparing the detection of the adsorption rates of total phosphorus, COD and ammonia nitrogen in example 3 of the present invention and comparative examples 1, 2 and 3;
FIG. 4 is a graph showing comparison between the detection of the removal rate of the adsorbent in example 3 of the present invention and that in comparative examples 1, 2 and 3;
FIG. 5 is a graph showing comparison between the adsorption rates of total phosphorus, COD and ammonia nitrogen and the removal rate of the adsorbent in example 7 and comparative example 4 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is obvious that the embodiments described are only some representative embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
Example 1
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: heating 1g of ferric chloride hexahydrate and 2g of ferrous chloride tetrahydrate to the reaction temperature of 50 ℃ in a nitrogen atmosphere, then dropwise adding 10mL of 20 wt% ammonia water, reacting at constant temperature for 2h under the protection of nitrogen, cooling to room temperature, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 2g of magnetic nanoparticles and 20mL of 20 wt% ammonia water into deionized water, heating to a reaction temperature, dropwise adding 0.01g of silane coupling agent, reacting at a constant temperature for 3 hours under the protection of nitrogen, adding 10g of mussel shell powder, continuing to react for 2 hours, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and separating by using a magnet for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 20min, adding organic acid, stirring at room temperature for 6 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 6 hr, and grinding to obtain modified mussel shell filler.
Example 2
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: heating 1g of ferric chloride hexahydrate and 3g of ferrous chloride tetrahydrate to the reaction temperature of 60 ℃ in a nitrogen atmosphere, then dropwise adding 30mL of 24 wt% ammonia water, reacting at constant temperature for 5 hours under the protection of nitrogen, cooling to room temperature, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 2g of magnetic nanoparticles and 40mL of 24 wt% ammonia water into deionized water, heating to the reaction temperature, dropwise adding 0.03g of silane coupling agent, carrying out nitrogen protection constant-temperature reaction for 6 hours, adding 10g of mussel shell powder, continuing the reaction for 3 hours, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and carrying out magnet separation for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 30min, adding organic acid, stirring at room temperature for 12 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 9 hr, and grinding to obtain modified mussel shell filler.
Example 3
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: heating 1g of ferric chloride hexahydrate and 2.5g of ferrous chloride tetrahydrate to 55 ℃ in a nitrogen atmosphere, then dropwise adding 20mL of 22 wt% ammonia water, reacting at a constant temperature for 3.5h under the protection of nitrogen, cooling to room temperature, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 2g of magnetic nanoparticles and 30mL of 22 wt% ammonia water into deionized water, heating to the reaction temperature, dropwise adding 0.02g of silane coupling agent, reacting at constant temperature for 4.5h under the protection of nitrogen, adding 10g of mussel shell powder, continuing to react for 2.5h, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and separating a magnet for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 25min, adding organic acid, stirring at room temperature for 9 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 7 hr, and grinding to obtain modified mussel shell filler.
Example 4
An application of modified mussel shell filler prepared in example 3 in sewage treatment in a biological aerated filter, water enters the bottom of the filter from a water inlet tank, air and water are in the same direction from bottom to top, treated water flows out from the top, a certain amount of activated sludge is added as sludge seeds when a reactor is started, when the sludge settlement ratio reaches 30%, the modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration amount is 0.2L/min.
Example 5
An application of modified mussel shell filler prepared in example 3 in sewage treatment in a biological aerated filter, wherein water enters the bottom of the filter from a water inlet tank, air and water are in the same direction from bottom to top, treated water flows out from the top, a certain amount of activated sludge is added as sludge seeds when a reactor is started, when the sludge settlement ratio reaches 30%, the modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration amount is 0.4L/min.
Example 6
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: dissolving 0.7g of cobalt chloride hexahydrate in a book in nitrogen atmosphere, then dropwise adding 7mL of 20 wt% ammonia water, slowly adding 0.01g of sodium borohydride under the protection of nitrogen, reacting for 1h, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 2g of magnetic nanoparticles and 20mL of 20 wt% ammonia water into deionized water, heating to a reaction temperature, dropwise adding 0.01g of silane coupling agent, reacting at a constant temperature for 3 hours under the protection of nitrogen, adding 10g of mussel shell powder, continuing to react for 2 hours, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and separating by using a magnet for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 20min, adding organic acid, stirring at room temperature for 6 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 6 hr, and grinding to obtain modified mussel shell filler.
Example 7
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: dissolving 1g of cobalt chloride hexahydrate in a book in nitrogen atmosphere, then dropwise adding 20mL of 24 wt% ammonia water, slowly adding 0.01g of sodium borohydride under the protection of nitrogen, reacting for 2 hours, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 2g of magnetic nanoparticles and 40mL of 24 wt% ammonia water into deionized water, heating to the reaction temperature, dropwise adding 0.03g of silane coupling agent, carrying out nitrogen protection constant-temperature reaction for 6 hours, adding 10g of mussel shell powder, continuing the reaction for 3 hours, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and carrying out magnet separation for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 30min, adding organic acid, stirring at room temperature for 12 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 9 hr, and grinding to obtain modified mussel shell filler.
Example 8
An application of the modified mussel shell filler prepared in example 7 in sewage treatment in a biological aerated filter is characterized in that water enters the bottom of the filter from a water inlet tank, air and water are in the same direction from bottom to top, the treated water flows out from the top, a certain amount of activated sludge is added as sludge seeds when a reactor is started, when the sludge settlement ratio reaches 30%, the modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration amount is 0.2L/min.
Example 9
An application of the modified mussel shell filler prepared in example 7 in sewage treatment in a biological aerated filter is characterized in that water enters the bottom of the filter from a water inlet tank, air and water are in the same direction from bottom to top, the treated water flows out from the top, a certain amount of activated sludge is added as sludge seeds when a reactor is started, when the sludge settlement ratio reaches 30%, the modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration amount is 0.4L/min.
Comparative example 1
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: heating 5g of ferric chloride hexahydrate and 1g of ferrous chloride tetrahydrate to 55 ℃ in a nitrogen atmosphere, then dropwise adding 50mL of 22 wt% ammonia water, reacting at constant temperature for 3.5h under the protection of nitrogen, cooling to room temperature, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating magnets for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 10g of magnetic nanoparticles and 10mL of 22 wt% ammonia water into deionized water, heating to the reaction temperature, dropwise adding 0.05g of silane coupling agent, reacting at constant temperature for 4.5h under the protection of nitrogen, adding 10g of mussel shell powder, continuing to react for 2.5h, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and separating a magnet for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 25min, adding organic acid, stirring at room temperature for 9 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 7 hr, and grinding to obtain modified mussel shell filler.
Comparative example 2
A preparation method of a modified mussel shell filler comprises the following steps:
s1, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s2, preparing the modified mussel shell filler: adding mussel shell powder into deionized water, stirring for 25min, adding organic acid, stirring at room temperature for 9 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 7 hr, and grinding to obtain modified mussel shell filler.
Comparative example 3
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: heating 1g of ferric chloride hexahydrate and 2.5g of ferrous chloride tetrahydrate to 55 ℃ in a nitrogen atmosphere, then dropwise adding 20mL of 22 wt% ammonia water, reacting at a constant temperature for 3.5h under the protection of nitrogen, cooling to room temperature, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 2g of magnetic nanoparticles and 30mL of 22 wt% ammonia water into deionized water, heating to the reaction temperature, dropwise adding 0.02g of silane coupling agent, reacting at constant temperature for 4.5h under the protection of nitrogen, adding 10g of mussel shell powder, continuing to react for 2.5h, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and carrying out magnet separation to obtain the magnetic mussel shell.
Comparative example 4
A preparation method of a modified mussel shell filler comprises the following steps:
s1, preparation of magnetic nanoparticles: dissolving 10g of cobalt chloride hexahydrate in a book in nitrogen atmosphere, then dropwise adding 10mL of 24 wt% ammonia water, slowly adding 0.01g of sodium borohydride under the protection of nitrogen, reacting for 2 hours, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding 10g of magnetic nanoparticles and 10mL of 24 wt% ammonia water into deionized water, heating to the reaction temperature, dropwise adding 0.05g of silane coupling agent, reacting at constant temperature under the protection of nitrogen for 6 hours, adding 10g of mussel shell powder, continuing to react for 3 hours, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and separating by using a magnet for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 30min, adding organic acid, stirring at room temperature for 12 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 9 hr, and grinding to obtain modified mussel shell filler.
Test example 1
The results of the detection of the adsorption rates of COD, total phosphorus and total ammonia nitrogen in the sewage and the removal rate of the adsorbent after adsorption in examples 4 and 5 and examples 8 and 9 of the invention are shown in FIG. 1 and FIG. 2. Note in fig. 1: a is p <0.05 compared to example 4; b is p <0.05 compared to example 4; c is p <0.05 compared to example 4. In fig. 2, note that: p is <0.05 compared to example 4.
As can be seen from fig. 1 and 2, the adsorption efficiencies of the modified mussel shells prepared in examples 4 and 5 and examples 8 and 9 on COD, total phosphorus and total ammonia nitrogen in sewage all reach more than 98%, wherein the adsorption efficiencies of example 5 on COD and ammonia nitrogen are the highest and reach 99.7% and 99.5%, respectively, and the adsorption rate of example 9 on total phosphorus is the highest and reaches 99.2%.
As can be seen from fig. 1 and 2, in examples 4, 5, 8 and 9, the removal rate was 99.2% by removing with a magnet after adsorption, and the removal rate of the adsorbent was 99.8% in example 4.
Test example 2
The modified mussel shell filler prepared in example 3 and comparative examples 1-3 is used for treating sewage in an aeration biological filter, the adsorption rate of COD, total phosphorus and total ammonia nitrogen in the sewage and the removal rate of an adsorbent after adsorption are detected, water enters the bottom of the filter from a water inlet tank, air and water are in the same direction from bottom to top, the treated water flows out from the top, a certain amount of activated sludge is added as sludge seeds when a reactor is started, when the sludge settlement ratio reaches 30%, the modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration amount is 0.3L/min. The results are shown in FIGS. 3 and 4. Note in FIG. 3: a is p <0.05 compared to comparative example 3; b is p <0.05 compared to comparative example 3; c is p <0.05 compared to comparative example 3. Note in fig. 4: p is <0.05 compared to comparative example 2.
As can be seen from FIGS. 3 and 4, in comparative example 1, compared with example 3, the ratio of raw materials is different, the performance of the modified mussel shell is different, the structure is also different, the adsorption efficiency of COD, total phosphorus and total ammonia nitrogen in sewage is obviously reduced, and the modified mussel shell filler prepared in example 3 is inferior.
As can be seen from FIGS. 3 and 4, in comparative example 2, in comparison with example 3, magnetic mussel shell was not prepared, and the Ca on the surface of the prepared modified mussel shell filler was obtained although mussel shell powder was modified with organic acid2+Dissolve out, organic acid remains on modified mussel shell filler surface, breeds anaerobic bacteria, gets into in the sewage through aeration equipment, removes the total phosphorus in the sewage, consumes COD and the ammonia nitrogen waste in the sewage, but its adsorption efficiency to COD in the sewage, total phosphorus and total ammonia nitrogen still is not as embodiment 3, and its clearance greatly reduced, and the removal effect is not good, still has great pollution after purifying sewage.
As can be seen from FIGS. 3 and 4, in comparative example 3, the magnetic mussel shell prepared without treating the shell with an organic acid has no surface Ca, as compared with example 32+The modified mussel shell filler is not dissolved out, no organic acid remains on the surface of the modified mussel shell filler, anaerobic bacteria are fewer, the total phosphorus in the sewage is removed, the efficiency of consuming COD and ammonia nitrogen wastes in the sewage is obviously reduced, the modified mussel shell filler is not as good as the modified mussel shell filler prepared in example 3, but the removal rate is close to that of example 3.
Test example 3
The modified mussel shell filler prepared in example 7 and comparative example 4 is used for treating sewage in an aeration biological filter, the adsorption rate of COD, total phosphorus and total ammonia nitrogen in the sewage and the removal rate of an adsorbent after adsorption are detected, water enters the bottom of the filter from a water inlet tank, air and water are in the same direction from bottom to top, the treated water flows out from the top, a certain amount of activated sludge is added as a sludge seed when a reactor is started, when the sludge settlement ratio reaches 30%, the modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration amount is 0.3L/min. The results are shown in FIG. 5. Note that: a is p <0.05 compared to comparative example 4; b is p <0.05 compared to comparative example 4, c is p <0.05 compared to comparative example 4, d is p <0.05 compared to comparative example 4.
As can be seen from fig. 5, in comparative example 3, compared with example 7, the ratio of raw materials is different, the properties of the prepared modified mussel shell are different, the structure is also different, the adsorption rate of the modified mussel shell to COD, total phosphorus and total ammonia nitrogen in sewage and the removal rate of the adsorbent are obviously reduced, and the modified mussel shell filler prepared in example 7 is inferior.
Compared with the prior art, the method has the advantages that the carbonized mussel shell is connected with the mussel shell powder carbonized at high temperature through the silane coupling agent, so that the prepared mussel shell powder is magnetic, is convenient for magnetic separation, avoids complex steps of filtering, centrifuging and the like on an adsorbent after dye is removed, and simplifies operation;
CaCO of shell3The components are gradually dissolved in an acidic environment and Ca is released2+These Ca2+Can react with PO under certain conditions4 3-The magnetized mussel shell powder is treated by organic acid to form Ca2+Dissolving out, meanwhile, organic acid is remained on the surface of the modified mussel shell filler, anaerobic bacteria are easy to breed, and the organic acid enters sewage through an aeration device, so that the total phosphorus in the sewage is efficiently removed, COD (chemical oxygen demand) and ammonia nitrogen waste in the sewage are consumed, and the sewage purification effect is achieved;
the mussel shell powder is modified by adopting the epoxy hydrocarbon silane coupling agent, and the mussel shell powder contains more carboxyl groups on calcium carbonate, so that the efficient coupling effect is achieved, the coupling efficiency is further improved, and the using amount of the coupling agent is reduced;
the modified mussel shell filler has good purification performance on sewage in the biological aerated filter, and has the advantages of simple modification conditions, convenient operation and strong operability. The waste mussel shells are used as raw materials, so that the method has good environmental benefits and can generate good economic benefits.
Various modifications may be made to the above without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is therefore intended to be limited not by the above description, but rather by the scope of the appended claims.
Claims (10)
1. A preparation method of a modified mussel shell filler is characterized by comprising the following steps:
s1, preparation of magnetic nanoparticles: heating ferric chloride hexahydrate and ferrous chloride tetrahydrate to reaction temperature in nitrogen atmosphere, dropwise adding ammonia water, reacting at constant temperature for 2-5h under the protection of nitrogen, cooling to room temperature, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating with magnet for later use;
s2, pretreatment of mussel shells: cleaning mussel shell brought back by a farm, removing residual shellfish meat, byssus and surface moss, drying at 100 deg.C, placing into a high temperature resistance furnace for nitrogen protection high temperature carbonization, heating to 50 deg.C every 10min, raising temperature to 800 deg.C at most, carbonizing for 30min, cooling, and grinding for use;
s3, preparing the magnetic mussel shell: respectively adding magnetic nanoparticles and ammonia water into deionized water, heating to reaction temperature, dropwise adding a silane coupling agent, reacting at constant temperature for 3-6h under the protection of nitrogen, adding mussel shell powder, continuing to react for 2-3h, cooling to room temperature, washing the synthesized magnetic mussel shell with deionized water for three times, and separating by using a magnet for later use;
s4, preparing the modified mussel shell filler: adding magnetic mussel shell into deionized water, stirring for 20-30min, adding organic acid, stirring at room temperature for 6-12 hr, washing with deionized water and anhydrous ethanol for three times, magnetically separating, drying at 80 deg.C for 6-9 hr, and grinding to obtain modified mussel shell filler.
2. The method for preparing the modified mussel shell filler according to claim 1, wherein the reaction temperature in step S1 is 50-60 ℃, and the mass ratio of the ferric chloride hexahydrate and the ferrous chloride tetrahydrate is 1: (2-3); the mass fraction of the ammonia water is 20-24%; the mass volume ratio of the ferric chloride hexahydrate to the ammonia water is 1: (10-30).
3. The method for preparing the modified mussel shell filler according to claim 1, wherein the mass ratio of the magnetic nanoparticles to the silane coupling agent to the mussel shell powder in step S3 is 2 (0.01-0.03): 10; the mass fraction of the ammonia water is 20-24%; the mass-volume ratio of the magnetic nanoparticles to the ammonia water is 1: (10-20).
4. The method for preparing a modified mussel shell filler according to claim 1, wherein the organic acid in step S4 is selected from one or more of citric acid, acetic acid, malic acid, formic acid, malonic acid, stearic acid, succinic acid, tartaric acid and ascorbic acid; the mass ratio of the magnetic mussel shell to the organic acid is 10: (2-5).
5. The method for preparing a modified mussel shell filler according to claim 1, wherein the silane coupling agent is an epoxy alkyl silane coupling agent selected from KH560, KH791 and Nada-73.
6. A modified mussel shell filler obtained by the process of any one of claims 1 to 5.
7. Use of the modified mussel shell filler of claim 6 in biological aerated filter treatment of sewage.
8. The use of the modified mussel shell filler in the treatment of sewage in an aeration biological filter according to claim 7, wherein water enters the bottom of the filter from a water inlet tank, air and water flow in the same direction from bottom to top, the treated water flows out from the top, a certain amount of activated sludge is added as sludge seeds when the reactor is started, when the sludge settling ratio reaches 30%, the modified mussel shell filler is added, the hydraulic retention time is 8 hours, and the aeration amount is 0.2-0.4L/min.
9. The method for preparing the modified mussel shell filler according to claim 1, wherein the magnetic nanoparticles are prepared by: dissolving cobalt chloride hexahydrate in a book in nitrogen atmosphere, then dropwise adding ammonia water, slowly adding sodium borohydride under the protection of nitrogen, reacting for 1-2h, washing the synthesized magnetic nanoparticles with deionized water for three times, and separating by using a magnet for later use.
10. The method for preparing the modified mussel shell filler according to claim 9, wherein the mass ratio of cobalt chloride hexahydrate to sodium borohydride is (70-100): 1; the mass fraction of the ammonia water is 20-24%; the mass ratio of the cobalt chloride hexahydrate to the ammonia water is 1: (10-20).
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| CN113713777A (en) * | 2021-09-13 | 2021-11-30 | 湖南农业大学 | Preparation method of eggshell powder vomitoxin adsorbent |
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