CN110787777A

CN110787777A - Adsorbent for adsorbing antimony ions or total phosphorus

Info

Publication number: CN110787777A
Application number: CN201910947789.4A
Authority: CN
Inventors: 延卫; 王宁; 冯江涛; 陈杰; 李晶晶; 杨国锐; 王嘉楠
Original assignee: Xian Jiaotong University
Current assignee: Xian Jiaotong University
Priority date: 2019-10-08
Filing date: 2019-10-08
Publication date: 2020-02-14

Abstract

The application relates to a composite adsorbent for adsorbing antimony ions or total phosphorus, which comprises a metal oxide or hydrate of the metal oxide, a conductive polymer and a coupling agent; the conductive polymer is an organic polymer, the molecular composition of which contains at least one of N or S, and the conductivity of the material after being soaked for 1 hour by 1mol/L hydrochloric acid is more than two orders of magnitude higher than that of the material after being soaked for 1 hour by 1mol/L sodium hydroxide solution; or the molecular composition of the conductive polymer contains at least one of N or S and has a single-double bond alternating structure; the coupling agent contains more than 15% of carbon-containing elements in molecules, and the molecular composition contains at least one of amino, carboxyl, hydroxyl or sulfonic group; or the coupling agent is one or the combination of any of organic acid, organic amine, silicon-hydroxyl-containing compound and amino acid of an alkane chain of C1-C10; the metal oxide is titanium dioxide. The composite adsorbent is simple in synthesis and convenient to use, and has a good adsorption effect on antimony ions or total phosphorus.

Description

Adsorbent for adsorbing antimony ions or total phosphorus

Technical Field

The application relates to an adsorbent for adsorbing antimony ions or total phosphorus, a membrane protective agent containing the adsorbent and a water treatment agent, in particular to a metal oxide/conductive polymer composite adsorbent which is suitable for the technical field of wastewater treatment.

Background

In recent years, China generates about 700 hundred million cubic cubes of various waste water every year. Although some of these waste waters have been treated, the waste waters still contain organic pollutants, inorganic substances, and the like to some extent, and show high concentrations of COD and BOD, high chromaticity, high levels of nutrients (total phosphorus, total nitrogen, and the like) and heavy metal ions (for example, copper ions, lead ions, antimony ions, zinc ions, and the like), and the like. Moreover, the waste water generally contains a plurality of pollutants or a plurality of heavy metal ions at the same time, the waste water containing only one pollutant is very rare, and the discharge of the waste water into the environment can cause great harm to the environment. Especially, the national emission standard of various pollutants and the environmental requirements of the public are continuously improved, and the removal of the substances in the wastewater is more and more important. Especially, under the condition that the concentration of various pollutants contained in the wastewater after the wastewater is subjected to pretreatment is relatively low, the concentration of the pollutants is further reduced, which is a problem to be solved in the field of environment in recent years.

The adsorption method can effectively reduce the concentration of pollutants in the wastewater, and particularly has obvious advantages for removing the pollutants with lower concentration. For example: the adsorption method has the advantages of simple operation, low energy consumption, low cost, no secondary pollution and the like, and is an effective method for removing various low-concentration pollutants. During the adsorption operation, the most central one is the adsorbent with excellent performance. The preferred adsorbent needs to have the characteristics of low cost, simple preparation, convenient use, high organic matter removal efficiency, easy regeneration and the like.

The conductive polymer is a macromolecule with long-chain conjugated pi bonds, and has excellent physicochemical properties, particularly electrochemical properties. Due to its reversible "doping-dedoping" properties as well. In recent years, more and more researches are carried out to apply the organic silicon composite material to the aspect of adsorption of water body pollutants, and the renewable performance of the organic silicon composite material is improved by virtue of the doping-de-doping performance of the organic silicon composite material. However, the use of conductive polymers as adsorbents has disadvantages in that, first, the adsorption capacity is low; secondly, the density of the adsorbent is lower than that of water, so that the adsorbent has great problems in the aspects of mixing with water body for adsorption and separation after the adsorption is finished.

The composite material technology, especially the organic-inorganic composite material technology opens up a new field for researching new materials. Organic and inorganic materials can be compounded to generate new performances which are not possessed by single organic or inorganic materials while the original characteristics of each component material are kept, so that research and exploration of novel organic-inorganic composite materials are increasingly paid attention by scientists.

The Chinese patent with the application number of CN200510057168.7 discloses a metal oxide conductive powder/polyaniline conductive polymer composite material and a preparation method thereof, wherein the composite material comprises the following raw material substances: the preparation method comprises the steps of mixing the aqueous solution of the aniline monomer with the aqueous solution of the doping acid, adding the metal oxide conductive powder into the mixture, stirring and mixing the mixture, adding the aqueous solution of the oxidant into the mixture to react, and collecting a target product from a reaction product. The Chinese patent with the application number of CN201611178355.5 discloses a preparation method of a polypyrrole composite nascent manganese dioxide adsorbent, wherein the adsorbent is obtained by carrying out oxidative polymerization on pyrrole monomers and nascent manganese dioxide. The Chinese patent with the application number of CN201310092391.X discloses a preparation method and application of a polyaniline/titanium dioxide/graphene conductive composite membrane, wherein 3-60 wt% of titanium dioxide, 0.05-5 wt% of graphene and 0.6-10 wt% of aniline are added into a protonic acid solution, an in-situ polymerization method is adopted to prepare a polyaniline/titanium dioxide/graphene composite material, and graphene enhances the adhesion capacity and the conductive capacity of the composite material. The above prior arts are all obtained by oxidative polymerization of metal oxide and pyrrole monomer or aniline monomer, wherein the comonomers are compounds with relatively low molecular weight and do not show the property of conductivity.

The Chinese patent with the application number of CN201710033951.2 discloses a star-shaped adsorbent, which comprises metal hydroxide particles with flocculation and a plurality of grafts connected to the surfaces of the metal hydroxide particles, wherein the adsorbent is in a star-shaped structure, and the star-shaped structure takes the metal hydroxide particles as the center. The adsorbent is prepared by selecting metal hydroxide particles with flocculation capacity as base materials, grafting polyacrylamide on the surfaces of the number-of-hydroxide particles by a free radical polymerization method to obtain a high-efficiency inorganic-organic hybrid flocculant, and introducing a large amount of functional group dithiocarbamate for adsorbing heavy metal ions on a star-shaped framework. The formation of the graft is mainly coupled by means of chemical bonds, and the graft cannot be separated from the graft and has complete irreversibility, so that the graft and the graft are difficult to form a synergistic adsorption effect in the adsorption process.

The Chinese patent with the application number of CN201810957111.X discloses a preparation method of a cellulose-based adsorbent for removing antimony ions in printing and dyeing wastewater. According to the invention, polyaniline is doped in the traditional cellulose-based adsorption material, so that the polyaniline has a good complexing effect on antimony ions, and can be adsorbed by carrying out an oxidation-reduction reaction with the antimony ions, so that the antimony ions in the printing and dyeing wastewater are effectively removed, the harm of heavy metal antimony to natural water is reduced, and important environmental and social benefits are achieved.

The Chinese patent with application number CN201711444947.1 discloses a method for simultaneously removing COD and total phosphorus, which at least comprises the following sewage treatment steps: 1) carrying out pre-mixing reaction on the sewage and ferrate; 2) conveying the mixture reacted in the step 1) to a packed tower through a pipeline for catalytic reaction, and performing adsorption filtration; the catalytic filler in the packed tower comprises the following substances in percentage by mass: 60-80% of active carbon, 10-30% of ferric hydroxide and 5-10% of metal catalyst. Because the filtering and adsorbing dephosphorization effects of ferrate and filler are combined, the using amount of the medicament is reduced, which is only about 1% of the adding amount of the traditional chemical dephosphorization process, and no sludge is generated.

Disclosure of Invention

The composite adsorbent is simple to synthesize, convenient to use and good in adsorption effect on antimony ions or total phosphorus, wherein a conductive polymer and an inorganic metal oxide are compounded to obtain a composite adsorbent material, the synthesized composite adsorbent material is easy to regenerate and can be recycled for multiple times, and the cost of an adsorption process is greatly reduced.

The present application relates to a composite adsorbent for adsorbing antimony ions or total phosphorus, comprising a metal oxide or a hydrate of a metal oxide, a conductive polymer, and a coupling agent for compounding the metal oxide or the hydrate of a metal oxide with the conductive polymer; the conductive polymer is an organic polymer, the molecular composition of which contains at least one of N or S, and the conductivity of the material after being soaked for 1 hour by 1mol/L hydrochloric acid is more than two orders of magnitude higher than that of the material after being soaked for 1 hour by 1mol/L sodium hydroxide solution; or the molecular composition of the conductive polymer contains at least one of N or S and has a single-double bond alternating structure; the coupling agent contains more than 15% of carbon-containing element in the molecule, and the molecular composition contains at least one of amino, carboxyl, hydroxyl or sulfonic group, and can be organic matter or organic acid salt; or the coupling agent is one or the combination of any of organic acid, organic amine, silicon-hydroxyl-containing compound and amino acid of an alkane chain of C1-C10; the metal oxide is titanium dioxide.

Preferably, the conductive polymer is one or a mixture of polypyrrole, polyaniline, polythiophene, polypyrrole methylene polymers or polypyrrole methane polymers. More preferably, the conductive polymer is polyaniline.

Preferably, the organic acid in the coupling agent is one or a mixture of more of monobasic acid, dibasic acid and tribasic acid; the organic amine in the coupling agent is a mono-amine, a di-amine or a tri-amine, or is a mixture of one or more of primary, secondary and tertiary amines.

Preferably, the weight ratio of the metal oxide or the hydrate of the metal oxide to the conductive polymer is 1-500: 100, and the weight ratio of the coupling agent to the conductive polymer is 0.01-10: 100.

Preferably, the regeneration method comprises the following steps: the regeneration method of the adsorbent for adsorbing the antimony ions comprises the following steps: firstly, the concentration of the used composite adsorbent is 0.01-15 mol.L^-1Soaking in the acid solution for 1-120 min; carrying out solid-liquid separation for the first time; then, putting the separated solid into a solution with the concentration of 0.01-15 mol.L^-1Soaking in the aqueous alkali for 1-120 min; carrying out solid-liquid separation for the second time to obtain the regenerated composite adsorbent;

the regeneration method for the adsorption total phosphorus adsorbent comprises the following steps: firstly, the concentration of the used composite adsorbent is 0.01-15 mol.L^-1Soaking in the aqueous alkali for 1-120 min; carrying out solid-liquid separation for the first time; then, putting the separated solid into a solution with the concentration of 0.01-15 mol.L^-1Soaking in the acid solution for 1-120 min; and carrying out solid-liquid separation for the second time to obtain the regenerated composite adsorbent.

The application also relates to a membrane protectant and a water treatment agent comprising a composite adsorbent as described above.

According to the composite adsorbent, the beneficial technical effects comprise that:

1. according to the invention, the metal oxide and the conductive polymer are combined, and the bonding force of the two components is enhanced through the coupling agent, so that the prepared composite adsorbent has better adsorption and regeneration performances, the raw materials are easy to obtain, the synthesis process is simple, and the cost is low;

2. the composite adsorbent provided by the invention has the advantages of small usage amount, large pollutant adsorption amount, short adsorption balance time and low pollutant treatment cost;

3. the composite adsorbent material provided by the invention can be suitable for adsorbing and removing different pollutants in wastewater, and has broad adsorption spectrum;

4. the composite adsorbent provided by the invention has excellent regeneration performance, almost no loss of the adsorption performance of the regenerated adsorbent, still has good adsorption performance after repeated regeneration, and is suitable for large-scale industrial production and application.

5. Has extremely strong adsorption performance for antimony ions or total phosphorus in the mixed pollutant solution.

Detailed Description

Hereinafter, embodiments of the present application will be described in detail to make objects, technical solutions and advantages of the present application more apparent. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The composite adsorbent is a composite adsorbent material formed by coupling and combining an inorganic material and an organic material through a coupling agent, and can be used for simultaneously adsorbing and removing pollutants such as chromaticity, COD (chemical oxygen demand), total phosphorus, heavy metal ions and the like in water. The inorganic material in the composition of the adsorbent is metal oxide, the organic material is conductive polymer, and the coupling agent is organic substance or organic salt.

The composite adsorbent comprises a metal oxide or a hydrate of the metal oxide, a conductive polymer and a coupling agent for compounding the metal oxide or the hydrate of the metal oxide with the conductive polymer; the conductive polymer is an organic polymer, the molecular composition of which contains at least one of N or S, and the conductivity of the material after being soaked for 1 hour by 1mol/L hydrochloric acid is more than two orders of magnitude higher than that of the material after being soaked for 1 hour by 1mol/L sodium hydroxide solution; or the molecular composition of the conductive polymer contains at least one of N or S and has a single-double bond alternating structure; the coupling agent contains more than 15% of carbon-containing element in the molecule, and the molecular composition contains at least one of amino, carboxyl, hydroxyl or sulfonic group, and can be organic matter or organic acid salt; or the coupling agent is one or the combination of any one of organic acid, organic amine, silicon hydroxyl compound and amino acid of an alkane chain of C1-C10.

Experiments show that the optimal choice of metal oxide for adsorbing antimony ions or total phosphorus from a mixed solution containing multiple metal ions is TiO₂The metal oxide may also be Fe₃O₄、Al₂O₃、MnO₂One or a mixture of more of ZnO and MgO. The conductive polymer can be one or a mixture of polypyrrole, polyaniline, polythiophene, polypyrrole methylene polymers or polypyrrole methane polymers, and is preferably polyaniline.

Preferably, the weight ratio of the metal oxide or the hydrate of the metal oxide to the conductive polymer is 1-500: 100, and the weight ratio of the coupling agent to the conductive polymer is 0.01-10: 100. That is, when the weight of the conductive polymer is taken as a reference value of 100, the weight of the metal oxide or the hydrate of the metal oxide is 1 to 500, and the weight of the coupling agent is 0.01 to 10. More preferably, the weight ratio of the metal oxide or the hydrate of the metal oxide to the conductive polymer is 50-400: 100, and the weight ratio of the coupling agent to the conductive polymer is 2-9: 100. Most preferably, the weight ratio of the metal oxide or the hydrate of the metal oxide to the conductive polymer is 100-250: 100, and the weight ratio of the coupling agent to the conductive polymer is 3-8: 100.

The metal oxide referred to in this application is combined with water after contacting with water to form a hydrate of the metal oxide, that is, hydroxyl is formed on the surface of the metal oxide. The organic acid in the coupling agent can be one or a mixture of more of monobasic, dibasic and tribasic acids, and the amine can be one or a mixture of more of monobasic, dibasic or tribasic amines and primary and secondary tertiary amines. The organic acid is mainly used as a coupling agent, acid radical groups in the organic acid enter a molecular chain of the conductive polymer through doping, and meanwhile, hydrogen bonds are formed between the acid radical groups and hydroxyl groups on the oxide, so that the conductive polymer and the oxide are tightly combined together. The prior art pickling, which mainly utilizes the acidity of the used acid to remove some substances from the surface of the material to be washed, is completely different from the action mechanism of the organic acid used in the present application.

The structure of the composite adsorbent can be that the metal oxide is coated in the conductive polymer material, or the conductive polymer is coated in the metal oxide, or the two substances are embedded and mixed with each other, and the two components are coupled together by a coupling agent. The conductive polymer in the material is mainly used for firmly combining with the metal oxide or the hydrate of the metal oxide under the action of the coupling agent, and the characteristic of good environmental stability of the conductive polymer is utilized, so that on one hand, the adsorption performance of the metal oxide or the hydrate of the metal oxide is enhanced, including the adsorption capacity of the conductive polymer on pollutants is improved, and the desorption regeneration performance of the conductive polymer is improved; another aspect is to protect the metal oxide or metal oxide hydrate from the environment. The metal oxide or the hydrate of the metal oxide is firmly combined with the conductive polymer under the action of the coupling agent, so that on one hand, the density of the composite adsorbent material is improved, and the composite adsorbent material can be better subjected to solid-liquid separation after adsorption is finished; on the other hand, the conductive polymer can improve the adsorption performance of pollutants under the synergistic action with the conductive polymer, including adsorption capacity and desorption regeneration performance. The coupling agent has the main function of organically combining the conductive polymer and the metal oxide or the hydrate of the metal oxide, and enhancing the binding force between the conductive polymer and the metal oxide or the hydrate of the metal oxide, so that the adsorption performance and the stability of the compound are improved, and the coupling agent does not directly act with adsorbate such as metal ions. The composite adsorbent is mainly used for adsorbing pollutants by virtue of acting forces such as electrostatic action, hydrogen bond action and coordination action.

The mechanism of action of the coupling agent includes the following aspects:

firstly, the coupling agent regulates and controls the doping state of the conductive polymer through functional groups on the molecular chain of the coupling agent, and regulates and controls the combination condition between the polymer and the oxide through changing the content and the distribution condition of the surface charges of the polymer. After regulation and control, the conductive polymer and the oxide are well compounded in a doping mode of hydroxyl or acid radical groups, amino groups, sulfonic groups and the like on the surface of the oxide, so that the conductive polymer can protect adsorption sites on the surface of the oxide, hydroxyl anions on the surface of the oxide and hydrogen ions are prevented from forming hydroxyl which is difficult to dissociate, and the reduction of adsorption capacity is avoided. In the presence of the coupling agent, hydroxyl groups on the metal oxide can dope the conductive polymer, so that the conductive polymer and the coupling agent are strongly combined.

Secondly, the coupling agent can modify dangling bonds or groups on the surface of the oxide through weak interaction, so that the coupling agent and the conductive polymer are combined more tightly. But this is very different from other chemically bonded grafting methods. For example, the two components are mainly bonded by chemical bonding, such as the two components cannot be separated after grafting and have complete irreversibility, so that the two components are difficult to form synergistic adsorption effect in the adsorption process. The coupling mechanism by the doping method is mainly combined by electrostatic action, hydrogen bond action and coordination action force, and has reversibility, so that coupling regulation and control can be realized by simple acid-base treatment, and the adsorption and desorption effects on the surface of the oxide are enhanced.

In conclusion, the coupling agent has the functions of enabling the surface of the oxide or the metal oxide hydrate to form abundant hydroxyl and form hydrogen bonds with functional groups on the coupling agent, so that the oxide or the metal oxide hydrate is combined more firmly; and secondly, the coupling agent and the conductive polymer can be doped into the conductive polymer chains through doping to form strong interaction, so that the coupling agent and the conductive polymer can be combined more tightly. Through the two actions, the coupling agent tightly combines the conductive polymer and the metal oxide/metal oxide hydrate together, so that the adsorption stability of the adsorbent is greatly improved. The third function of the coupling agent is to regulate and control the surface properties of the metal oxide/conductive polymer material, effectively increase the number of load charges on the surface of the composite material, change the potential value of the surface of the material and greatly improve the adsorption performance of the material on organic pollutants and heavy metal ions.

The conductive polymer can improve the adsorption performance of the adsorbent, belongs to a conjugated high molecular substance with a structure in which single bonds and double bonds alternately appear in a molecular structure, has a molecular weight of more than 1 ten thousand, and is different from a polymerized monomer with a lower molecular weight. The hydroxyl groups of the conductive polymer and the oxide in the conductive polymer/metal oxide composite material are combined in a mutual doping mode. When the composite material is applied to adsorption of substances such as heavy metal ions, under the state of higher pH value (pH > 3; namely low coupling agent concentration), the doped polymer generates ion exchange or de-doping behavior due to instability. The hydroxyl groups on the oxide are preferentially dedoped due to the relatively small charge. The negatively charged hydroxyl group binds to a substance in an aqueous solution in order to maintain electrical neutrality, and is selectively adsorbed by chelation, electrostatic adsorption, or pore adsorption. Therefore, the selective adsorption characteristics and adsorption performance of the composite material are determined by the oxide. The conductive polymer provides protection for hydroxyl groups on the surface of the oxide, so that the formation of hydroxyl groups (-OH) which are difficult to dissociate is avoided, the capacity of combining the hydroxyl groups with heavy metal ions is improved, and particularly, N and S in the conductive polymer can form coordinate bonds with the heavy metal ions, so that a chelating effect is achieved, and the adsorption capacity is improved. Therefore, under the synergistic effect, the adsorption performance and affinity of the composite material to the adsorbed substances are greatly improved.

Example one

The composite adsorbent material comprises conductive polymer polypyrrole, metal oxide titanium dioxide and coupling agent formic acid. The ratio of the three substances is titanium dioxide to polypyrrole to formic acid is 10:100: 0.1. The specific synthesis steps are as follows: firstly, adding 0.1 part of formic acid into 1000 parts of water at room temperature, stirring and dissolving, then dispersing 1.0 part of titanium dioxide into the solution, stirring for 1h, then adding 100 parts of polypyrrole, stirring for 8-12 h at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent of titanium dioxide, polypyrrole and formic acid, namely 10:100: 0.1.

Example two

The composite adsorbent material comprises conductive high-molecular polypyrrole, metal oxide manganese dioxide and a coupling agent oxalic acid. The ratio of the manganese dioxide to the polypyrrole to the oxalic acid is 50:100: 1.0. The specific synthesis steps are as follows: firstly, adding 1.0 part of oxalic acid into 1000 parts of water at room temperature, stirring and dissolving, then dispersing 50 parts of manganese dioxide into the solution, stirring for 1h, then adding 100 parts of polypyrrole, stirring for 8-12 h at 30 ℃, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent of manganese dioxide, polypyrrole and oxalic acid of 50:100: 1.0.

EXAMPLE III

The composite adsorbent material comprises conductive polymer polypyrrole, metal oxide ferroferric oxide and coupling agent caproic acid. The ratio of the three substances is 80:100: 2.0. The specific synthesis steps are as follows: firstly, adding 2.0 parts of hexanoic acid into 1000 parts of water at room temperature, stirring and dissolving, dispersing 80 parts of ferroferric oxide into the solution, adding 100 parts of polypyrrole, stirring at room temperature for 8-12 h, filtering, washing the obtained solid with a large amount of clear water, and drying at 50 ℃ for 12h to obtain the composite adsorbent containing ferroferric oxide, polypyrrole and hexanoic acid in a ratio of 80:100: 2.0.

Example four

The composite adsorbent material comprises conductive polymer polypyrrole, metal oxide aluminum oxide and coupling agent capric acid. The ratio of the three substances is 100:100: 3.6. The specific synthesis steps are as follows: firstly, adding 3.6 parts of capric acid into 1000 parts of water at room temperature, stirring and dissolving, dispersing 100 parts of aluminum oxide into the solution, adding 100 parts of polypyrrole, stirring for 8-12 h at 55 ℃, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent containing aluminum oxide, polypyrrole and capric acid in a ratio of 100:100: 3.6.

EXAMPLE five

The composite adsorbent material comprises conductive polymer polypyrrole, metal oxide zinc oxide and coupling agent butyric acid. The ratio of the three substances is zinc oxide polypyrrole butyric acid 300:100: 8. The specific synthesis steps are as follows: firstly, adding 8.0 parts of butyric acid into 1000 parts of water at room temperature, stirring and dissolving, then dispersing 300 parts of zinc oxide into the solution, stirring for 2 hours, then adding 100 parts of polypyrrole, stirring for 8-12 hours at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12 hours at 50 ℃ to obtain the composite adsorbent of titanium dioxide, polypyrrole and formic acid, namely 100:100: 3.6.

EXAMPLE six

The composite adsorbent material comprises conductive polymer polythiophene, metal oxide magnesium oxide and coupling agent triethylene diamine. The ratio of the three substances is magnesium oxide, polythiophene and triethylene diamine is 220:100: 9.8. The specific synthesis steps are as follows: firstly, adding 9.8 parts of triethylene diamine into 1000 parts of water at room temperature, stirring and dissolving, then dispersing 220 parts of magnesium oxide into the solution, then adding 100 parts of polythiophene, stirring for 8-12 h at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent of magnesium oxide, polythiophene and triethylene diamine (220: 100: 9.8).

EXAMPLE seven

The composite adsorbent material comprises conductive polymer polythiophene, metal oxide titanium dioxide and coupling agent hexamethylene diamine. The ratio of the three substances is titanium dioxide, polythiophene and hexanediamine is 200:100: 9.0. The specific synthesis steps are as follows: firstly, adding 9.0 parts of hexamethylenediamine into 1000 parts of water at room temperature, stirring and dissolving, then dispersing 200 parts of titanium dioxide into the solution, stirring for 8 hours, then adding 100 parts of polythiophene, stirring for 8-12 hours at 35 ℃, filtering, washing the obtained solid with a large amount of clear water, and drying for 12 hours at 50 ℃ to obtain the composite adsorbent of titanium dioxide, polythiophene and hexamethylenediamine, 200:100: 9.0.

Example eight

The composite adsorbent material comprises conductive polymer polyaniline, metal oxide manganese dioxide and coupling agent ethylenediamine. The ratio of the three substances is manganese dioxide, polyaniline and ethylenediamine is 150:100: 8.1. The specific synthesis steps are as follows: firstly, adding 8.1 parts of ethylenediamine into 1000 parts of water at room temperature, stirring and dissolving, then dispersing 150 parts of manganese dioxide into the solution, stirring for 1 hour at room temperature, then adding 100 parts of polyaniline, stirring for 8-12 hours at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12 hours at 50 ℃ to obtain the composite adsorbent with manganese dioxide, polyaniline and ethylenediamine being 150:100: 8.1.

Example nine

The composite adsorbent material comprises conductive polymer polyaniline, metal oxide aluminum oxide and coupling agent propylamine. The ratio of the three substances is aluminum oxide to polyaniline to propylamine is 135:100: 8.0. The specific synthesis steps are as follows: firstly, adding 8.0 parts of propylamine into 1000 parts of water at room temperature, stirring and dissolving, then dispersing 135 parts of aluminum oxide into the solution, stirring for 4 hours at room temperature, then adding 100 parts of polyaniline, stirring for 8-12 hours at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12 hours at 50 ℃ to obtain the composite adsorbent of aluminum oxide, polyaniline and propylamine, wherein the ratio of aluminum oxide to polyaniline to propylamine is 135:100: 8.0.

Example ten

The composite adsorbent material comprises conductive polymer polyaniline, metal oxide ferroferric oxide and coupling agent acetic acid. The ratio of the three substances is ferroferric oxide, polyaniline and acetic acid is 120:100: 7.6. The specific synthesis steps are as follows: firstly, adding 7.6 parts of acetic acid into 1000 parts of water at room temperature, stirring and dissolving, dispersing 120 parts of ferroferric oxide into the solution, stirring for 2 hours at room temperature, adding 100 parts of polyaniline, stirring for 8-12 hours at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12 hours at 50 ℃ to obtain the composite adsorbent of ferroferric oxide, polyaniline and acetic acid, wherein the ratio of the ferroferric oxide to the acetic acid is 120:100: 7.6.

EXAMPLE eleven

The composite adsorbent material comprises conductive polymer polyaniline, metal oxide zinc oxide and coupling agent trimethylsilane. The ratio of the three substances is zinc oxide, polyaniline and trimethylsilane is 100:100: 6.9. The specific synthesis steps are as follows: firstly, at room temperature, adding 6.9 parts of glutamic trimethylsilane into 1000 parts of water, stirring for 30min, dispersing 100 parts of zinc oxide into the solution, adding 100 parts of polyaniline, stirring for 8-12 h at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent of zinc oxide, polyaniline and trimethylsilane in a ratio of 100:100: 6.9.

Example twelve

The composite adsorbent material comprises conductive polymer polyaniline, polypyrrole, metal oxide titanium dioxide and coupling agent leucine. The ratio of the titanium dioxide to the polyaniline is as follows: polypyrrole leucine: 100:50:50: 7.0. The specific synthesis steps are as follows: firstly, adding 7.0 parts of leucine into 1000 parts of water at room temperature, stirring and dissolving, dispersing 100 parts of titanium dioxide into the solution, stirring for 5 hours at room temperature, adding 50 parts of polyaniline and 50 parts of polypyrrole, stirring for 8-12 hours at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12 hours at 50 ℃ to obtain titanium dioxide, namely polyaniline: polypyrrole leucine: 100:50:50:7.0 composite adsorbent.

EXAMPLE thirteen

The composite adsorbent material comprises conductive polymer polyaniline, polypyrrole, metal oxide aluminum oxide and coupling agent adipic acid. The proportion of the materials is aluminum oxide to polyaniline: polypyrrole: adipic acid 160:90:10: 6.0. The specific synthesis steps are as follows: firstly, at room temperature, adding 6.0 parts of adipic acid into 1000 parts of water, stirring and dissolving, dispersing 160 parts of aluminum oxide into the solution, adding 90 parts of polyaniline and 10 parts of polypyrrole, stirring at 60 ℃ for 8-12 h, filtering, washing the obtained solid with a large amount of clear water, and drying at 50 ℃ for 12h to obtain aluminum oxide: polypyrrole and adipic acid composite adsorbent.

Example fourteen

The composite adsorbent material comprises conductive polymer polyaniline, polypyrrole, metal oxide magnesium oxide and coupling agent pentanediamine. The ratio of the materials is magnesium oxide to polyaniline: polypyrrole pentanediamine 190:40:60: 4.8. The specific synthesis steps are as follows: firstly, at room temperature, adding 4.8 parts of pentamethylene diamine into 1000 parts of water, stirring and dissolving, dispersing 190 parts of magnesium oxide into the solution, adding 40 parts of polyaniline and 60 parts of polypyrrole, stirring for 2 hours at 50 ℃, filtering, washing the obtained solid with a large amount of clear water, and drying for 12 hours at 50 ℃ to obtain magnesium oxide, namely polyaniline: polypyrrole pentanediamine 190:40:60:4.8 composite adsorbent.

Example fifteen

The composite adsorbent material comprises conductive macromolecular polypyrrole methane, metal oxide titanium dioxide and coupling agent 3-aminopropyl trihydroxy silane. The ratio of the titanium dioxide to the polypyrrolylmethane to the 3-aminopropyltrihydroxysilane is 240 to 100 to 3.4. The specific synthesis steps are as follows: firstly, adding 3.4 parts of 3-aminopropyl trihydroxysilane into 1000 parts of water at room temperature, stirring for 30min, dispersing 240 parts of titanium dioxide into the solution, adding 100 parts of polypyrrole methane, stirring for 8-12 h at 50 ℃, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent of titanium dioxide polypyrrole methane 3-aminopropyl trihydroxysilane 240:100: 3.4.

Example sixteen

The composite adsorbent material comprises conductive high-molecular polypyrrole methylene, metal oxide manganese dioxide and a coupling agent diethylenetriamine. The proportion of the manganese dioxide, the polypyrrolylmethene and the diethylenetriamine is 260:100: 5.0. The specific synthesis steps are as follows: firstly, at room temperature, adding 5.0 parts of diethylenetriamine into 1000 parts of water, stirring and dissolving, then dispersing 260 parts of manganese dioxide into the solution, then adding 100 parts of polypyrrolylmethene, stirring for 10 hours at room temperature, filtering, washing the obtained solid with a large amount of clear water, and then drying for 12 hours at 50 ℃ to obtain the composite adsorbent of manganese dioxide, polypyrrolylmethene and diethylenetriamine, 260:100: 5.0.

Example seventeen

The composite adsorbent material comprises conductive high-molecular polypyrrole methylene, metal oxide aluminum oxide and a coupling agent heptanoic acid. The ratio of the materials is 380:100: 2.0. The specific synthesis steps are as follows: firstly, adding 2.0 parts of heptanoic acid into 1000 parts of water at room temperature, stirring for dissolving, dispersing 380 parts of aluminum oxide into the solution, stirring for 30min, adding 100 parts of polypyrrolamethylene, carrying out oxidative polymerization at room temperature for 8-12 h, filtering, washing the obtained solid with a large amount of clear water, and drying at 50 ℃ for 12h to obtain the composite adsorbent of aluminum oxide, polypyrrolamethylene and heptanoic acid 380:100: 2.0.

EXAMPLE eighteen

The composite adsorbent material comprises conductive polymer polypyrrole methane, polypyrrole methylene, metal oxide ferroferric oxide and coupling agent phenylalanine. The ratio of the materials is ferroferric oxide, namely polypyrrolylmethane, polypyrrolylmethene and phenylalanine is 100:40:60: 6.0. The specific synthesis steps are as follows: firstly, at room temperature, adding 6.0 parts of phenylalanine into 1000 parts of water, stirring and dissolving, dispersing 100 parts of ferroferric oxide into the solution, stirring for 60min, adding 40 parts of polypyrrole methane and 60 parts of polypyrrole methylene, stirring for 8-12 h at 50 ℃, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent containing ferroferric oxide, polypyrrole methane, polypyrrole methylene and phenylalanine, wherein the ratio of the ferroferric oxide to the polypyrrole methylene to the phenylalanine is 100:40:60: 6.0.

Example nineteen

The composite adsorbent material comprises conductive polymer polypyrrole methane, polypyrrole methylene, metal oxide titanium dioxide and coupling agent diphenyl dihydroxy silane. The ratio of the titanium dioxide to the polypyrrolylmethane to the polypyrrolylmethylene to the diphenyl dihydroxy silane is 200:80:20: 8.0. The specific synthesis steps are as follows: firstly, adding 8.0 parts of diphenyldihydroxysilane into 1000 parts of water at room temperature, stirring for 30min, dispersing 200 parts of titanium dioxide into the solution, stirring for 30min, adding 80 parts of polypyrrole methane and 20 parts of polypyrrole methylene, carrying out oxidative polymerization for 8-12 h at room temperature, filtering, washing the obtained solid with a large amount of clear water, and drying for 12h at 50 ℃ to obtain the composite adsorbent of titanium dioxide, polypyrrole methane, polypyrrole methylene and diphenyl dihydroxy silane, wherein the molar ratio of titanium dioxide to polypyrrole methylene to diphenyl dihydroxy silane is 200:80:20: 8.0.

The standard of consideration for selective adsorption of the target heavy metal ions by the composite material of the present application is selection by the degree of matching between the unit cell parameters of the heavy metal ion hydroxide and the unit cell parameters of the oxide. The higher the degree of matching, the stronger the material's selective adsorption of heavy metal ions. The mechanism of the metal oxide for absorbing heavy metal ions is similar to the epitaxial lattice growth theory. It can be expressed that in the process of adsorbing heavy metal ions, when the unit cell structure of the heavy metal ion hydrate (or hydroxyl complex) is matched with the unit cell structure of the oxide to a higher degree, the more preferentially the oxide is adsorbed to perform similar epitaxial lattice growth. It is to be noted that such a mode of adsorption is not "epitaxial growth" in the true sense, and it shows only one tendency and affinity. For adsorbing antimony ions, the unit cell structure of titanium dioxide is most closely matched with that of antimony ion hydrate, so that the selection of titanium dioxide as the metal oxide in the composite adsorbent is the optimal choice.

Examples of Selective adsorption of antimony ions or Total phosphorus

A500 mg/Sb (V) ion solution is roughly prepared by adopting potassium pyroantimonate (KSbO6H6) as a stock solution, the stock solution is diluted to a specific concentration in a gradient manner, an inductively coupled plasma atomic emission spectrometer (ICP-OES) is used for measuring the actual concentration of antimony ions, and the adsorption efficiency and the adsorption quantity are calculated according to the actual concentration. Preparing 0.5g/L stock solution, weighing 0.07165g of dry potassium dihydrogen phosphate with constant weight, adding water to dissolve, and fixing the volume in a 100mL volumetric flask; when in use, the solution is diluted by five times to standard solution (0.1 g/L); the total phosphorus concentration was determined by ammonium molybdate spectrophotometry.

Weighing 0.04g (two per thousand) or 0.02g (one per thousand) of polyaniline/titanium dioxide composite adsorbent into a 50mL centrifuge tube, adding 20mL of phosphate solution or Sb (V) solution, oscillating and adsorbing at normal temperature for 1h, centrifuging, filtering, collecting supernatant, and determining the content of residual phosphate (ultraviolet spectrophotometry) or antimony ions (ICP-OES) in the supernatant. The results are as follows:

the application also aims to relate to a using method of the composite adsorbent, which comprises the steps of adding the composite adsorbent provided by the application into wastewater to be treated, stirring for a certain time, then carrying out solid-liquid separation, and discharging the separated effluent, namely the treated water. The effective dosage of the adsorbent accounts for one ten thousandth to ten percent of the mass of the treated water. The stirring may be magnetic stirring, electric stirring, jet stirring or a method using air or inert gas bubbling stirring. The stirring time after the adsorbent and the wastewater are mixed is generally 10min to 300min, and the solid-liquid separation method can be filter cloth filtration, filter membrane filter pressing, centrifugal filtration, vacuum filtration, ultrafiltration, filter pressing and the like.

The application also aims to relate to a regeneration method of the composite adsorbent, which comprises the steps of sequentially soaking the adsorbent subjected to adsorption treatment in an acid-base solution to regenerate and activate the adsorbent, wherein the regenerated and activated composite adsorbent can respectively adsorb COD (chemical oxygen demand), chromaticity, total phosphorus, heavy metal ions and the like in treated water according to different regeneration and activation methods, and can be combined with a membrane treatment technology to treat different waste waters. The acid-base solution here may be an aqueous solution, an alcohol solution, or a mixed solution of water and alcohol of an acid or a base. The weight ratio of the acid-base solution to the adsorbent is 0.5: 1-100: 1. Preferably, the weight ratio of the acid-base solution to the adsorbent is 1: 1-50: 1.

The alkali used for regeneration and activation can be one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, barium hydroxide and ammonia water, and the concentration can be 0.01-15 mol.L^-1(ii) a The acid used for regeneration and activation can be one or a mixture of more of nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, hydrofluoric acid or C1-C10 alkane-based organic acid and organic acid with benzene ring and/or naphthalene ring, and the concentration can be 0.01-15 mol.L^-1. The contact soaking time of the acid-base solution on the regeneration of the composite adsorbent can be 1-120 min.

And soaking the adsorbent after adsorbing the pollutants in acid and alkali solutions for 1-120 min or in alkali and acid solutions for 1-120 min in sequence, so that desorption of the pollutants and regeneration of the adsorbent can be realized. The composite adsorbent can be used for the next adsorption treatment process after regeneration and activation, and the operation is very simple. The regeneration method of the composite adsorbent for adsorbing the total phosphorus comprises the step of firstly regenerating the used composite adsorbent at the concentration of 0.01-15 mol.L^-1Soaking in the aqueous alkali for 1-120 min; carrying out solid-liquid separation for the first time; then, putting the separated solid into a solution with the concentration of 0.01-15 mol.L^-1Soaking in the acid solution for 1-120 min; and carrying out solid-liquid separation for the second time to obtain the regenerated composite adsorbent. The regeneration method of the composite adsorbent for adsorbing antimony ions is just opposite, and the used composite adsorbent is firstly used at the concentration of 0.01-15 mol.L^-1Soaking in the acid solution for 1-120 min; carrying out solid-liquid separation for the first time; then, putting the separated solid into a solution with the concentration of 0.01-15 mol.L^-1Soaking in the aqueous alkali for 1-120 min; and carrying out solid-liquid separation for the second time to obtain the regenerated composite adsorbent. This is because, desorption with an alkali solution and regeneration with an acid solution can bring a positive charge to the surface of the composite material, thereby adsorbing anions (total phosphorus); the composite material is desorbed by an acid solution and regenerated by an alkali solution, so that the surface of the composite material can be charged with negative charges, and cations (antimony ions) can be adsorbed.

The advantages of adopting the composite adsorbent of the application to treat wastewater include:

the adsorption treatment process is simple, the treatment effect is good, and the chromaticity, COD, total phosphorus, heavy metal ions and the like of the wastewater can be removed simultaneously under proper conditions;

the adsorption treatment method is suitable for treating various waste water with lower concentration, including domestic sewage, printing and dyeing waste water, coking waste water, chemical industry waste water, paper-making waste water, metallurgical waste water, mineral processing waste water, oil refining waste water, food processing waste water, breeding waste water, electroplating waste water and the like;

the regeneration method of the adsorbent is simple, and the purpose of regeneration can be achieved only by simply soaking the adsorbed adsorbent with an acid-base solution.

Example one of use and regeneration

For pharmaceutical wastewater with 73 times of chroma, 89mg/L COD and 10.3mg/L Total Phosphorus (TP), five thousandths of adsorbent (the twelve adsorbents in the example) by weight percent is used for treating the wastewater, the wastewater is magnetically stirred for 150min and then filtered by using filter paper, and the filtrate is tested for chroma, COD and total phosphorus concentration. And (3) regenerating a filter cake, soaking for 10min by using a 1.0mol/L barium hydroxide solution, then carrying out solid-liquid separation, soaking the solid for 60min in 1.5mol/L sulfuric acid, and carrying out solid-liquid separation. The obtained solid is the regenerated adsorbent, and the regenerated adsorbent can be subjected to adsorption and regeneration again in the same way. The adsorption effect of the adsorbent is still not obviously changed after the cyclic regeneration for 4 times.

TABLE 1 effect of adsorbent cyclic adsorption treatment of pharmaceutical wastewater

Number of times of adsorption and regeneration	0	1	2	3	4
						Chroma/multiple	9	12	11	17	14
COD/(mg/L)	43.6	50.3	45.8	48.8	37.7
						TP/(mg/L)	0.19	0.27	0.36	0.28	0.21

Example two of use and regeneration

For chemical wastewater with the chroma of 97 times, the COD of 113mg/L and the total phosphorus of 9.8mg/L, ten percent of the adsorbent (the adsorbent in the thirteen embodiment in the adsorbent) is used for treating the wastewater, the wastewater is magnetically stirred for 150min and then filtered by using filter paper, and the chroma, the COD and the total phosphorus of the filtrate are tested. And (3) regenerating a filter cake, soaking for 60min by using 1.5mol/L ammonia water solution, then carrying out solid-liquid separation, soaking the solid in 1.5mol/L acetic acid solution for 20min, and carrying out solid-liquid separation. The obtained solid is the regenerated adsorbent, and the regenerated adsorbent can be subjected to adsorption and regeneration again in the same way. The adsorption effect of the adsorbent is still not obviously changed after the cyclic regeneration for 4 times.

TABLE 2 effect of chemical wastewater treatment by cyclic adsorption of adsorbent

Number of times of adsorption and regeneration	0	1	2	3	4
						Chroma/multiple	13	10	17	13	16
COD/(mg/L)	37.8	40.5	38.3	39.1	38.7
						TP/(mg/L)	0.23	0.29	0.26	0.18	0.27

Example three of use and regeneration

For chemical wastewater with 116 times of chroma, 92mg/L of COD and 8.7mg/L of total phosphorus, five percent of adsorbent (the adsorbent in the example eighteen in the adsorbent) is used for treating the wastewater, the wastewater is magnetically stirred for 180min and then filtered by using filter paper, and the filtrate is tested for chroma, COD and total phosphorus. And (3) regenerating a filter cake, soaking for 180min by using a 0.1mol/L calcium hydroxide solution, then carrying out solid-liquid separation, soaking the solid in a 3.0mol/L valeric acid solution for 30min, and carrying out solid-liquid separation. The obtained solid is the regenerated adsorbent, and the regenerated adsorbent can be subjected to adsorption and regeneration again in the same way. The adsorption effect of the adsorbent is still not obviously changed after the cyclic regeneration for 4 times.

TABLE 3 effect of chemical wastewater treatment by cyclic adsorption of adsorbent

Number of times of adsorption and regeneration	0	1	2	3	4
						Chroma/multiple	19	21	20	23	20
COD/(mg/L)	43.7	30.3	39.8	39.1	42.1
						TP/(mg/L)	0.17	0.13	0.16	0.21	0.15

Yet another aspect of the present application relates to a membrane protectant or a water treatment agent comprising a composite adsorbent as described above. Besides the above-mentioned removed substances, the composite adsorbent of the present application can effectively adsorb and remove the submicron particles in water, and particularly has good adsorption effect on soluble or slightly soluble organic small molecules and macromolecules such as protein, polysaccharide, humic acid, polymeric flocculant and the like in water, wherein the organic molecules are the main components of the submicron particles in water. The submicron particles are easy to attach to the surface of the membrane material and are easy to block the membrane pores because the particle size of the submicron particles is close to that of the membrane pores, so that the permeability of the membrane greatly slides down, and the membrane pressure is increased. The adsorbent can effectively adsorb the submicron particles in water, and meanwhile, the particles of the adsorbent are larger than 1 micron and far larger than the pore diameter of the membrane, and cannot be attached to the surface of the membrane material and block membrane pores, so that the membrane material is protected, the permeability of the membrane is kept, and the membrane pressure is not obviously increased in the operation process.

Although the embodiments disclosed in the present application are described above, the descriptions are only for the convenience of understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A composite adsorbent for adsorbing antimony ions or total phosphorus, comprising a metal oxide or a hydrate of a metal oxide, a conductive polymer, and a coupling agent for compounding the metal oxide or the hydrate of a metal oxide with the conductive polymer;

the conductive polymer is an organic polymer, the molecular composition of which contains at least one of N or S, and the conductivity of the material after being soaked for 1 hour by 1mol/L hydrochloric acid is more than two orders of magnitude higher than that of the material after being soaked for 1 hour by 1mol/L sodium hydroxide solution; or the molecular composition of the conductive polymer contains at least one of N or S and has a single-double bond alternating structure;

the coupling agent contains more than 15% of carbon-containing elements in molecules, and the molecular composition contains at least one of amino, carboxyl, hydroxyl or sulfonic group; or the coupling agent is one or the combination of any of organic acid, organic amine, silicon-hydroxyl-containing compound and amino acid of an alkane chain of C1-C10;

the metal oxide is titanium dioxide.

2. The composite adsorbent for adsorbing antimony ions or total phosphorus according to claim 1, wherein the conductive polymer is one or a mixture of polypyrrole, polyaniline, polythiophene, polypyrrole methylene polymers or polypyrrole methane polymers.

3. The composite adsorbent for adsorbing antimony ions or total phosphorus according to claim 1, wherein the conductive polymer is polyaniline.

4. The composite adsorbent for adsorbing antimony ions or total phosphorus according to claim 2, wherein the organic acid in the coupling agent is one or a mixture of monobasic, dibasic and tribasic acids.

5. The composite adsorbent for adsorbing antimony ions or total phosphorus according to claim 2, wherein the organic amine in the coupling agent is one or a mixture of a mono-amine, a di-amine or a tri-amine.

6. The composite adsorbent for adsorbing antimony ions or total phosphorus according to any one of claims 1 to 5, wherein the weight ratio of the metal oxide or the hydrate of the metal oxide to the conductive polymer is 1 to 500:100, and the weight ratio of the coupling agent to the conductive polymer is 0.01 to 10: 100.

7. The composite adsorbent for adsorbing antimony ions or total phosphorus according to claim 6, wherein the regeneration method for the adsorbent adsorbing antimony ions is: firstly, the concentration of the used composite adsorbent is 0.01-15 mol.L^-1Soaking in the acid solution for 1-120 min; carrying out solid-liquid separation for the first time; then, putting the separated solid into a solution with the concentration of 0.01-15 mol.L^-1Soaking in the aqueous alkali for 1-120 min; carrying out solid-liquid separation for the second time to obtain the regenerated composite adsorbent;

8. A membrane protective agent comprising the composite adsorbent according to any one of claims 1 to 7.

9. A water treatment agent comprising the composite adsorbent according to any one of claims 1 to 7.