CN111097373B

CN111097373B - Porous adsorption material and oxygen-carrying and adsorption composite functional material and application thereof

Info

Publication number: CN111097373B
Application number: CN201811249559.2A
Authority: CN
Inventors: 张洪刚; 刘李璇; 潘纲; 陈俊
Original assignee: Research Center for Eco Environmental Sciences of CAS
Current assignee: Research Center for Eco Environmental Sciences of CAS
Priority date: 2018-10-25
Filing date: 2018-10-25
Publication date: 2022-05-06
Anticipated expiration: 2038-10-25
Also published as: CN111097373A

Abstract

The invention provides a porous adsorption material, an oxygen-carrying and adsorption composite functional material and application thereof, the oxygen-carrying and adsorption composite functional material is used for repairing a water body, the problems of efficiently adsorbing pollutants such as nitrogen and phosphorus in the water body, improving water body anaerobism and the like can be solved, the cost is low, and the ecological safety is good. The composite functional material provided by the invention is prepared by carrying out pressure swing adsorption-oxygen loading on porous particles prepared from a modified base material, wherein the modified base material is prepared by sequentially carrying out impregnation modification on the base material by a metal cation salt solution and an alkaline solution, and then calcining at the high temperature of 1000 ℃ under 600-; the matrix material is selected from one or the combination of more than two of natural clay minerals, industrial solid wastes and activated carbon.

Description

Porous adsorption material, oxygen-carrying and adsorption composite functional material and application thereof

Technical Field

The invention belongs to the technical field of environmental science and engineering, and particularly relates to a water body repairing material prepared from natural and cheap materials and application of the water body repairing material in water environment repairing.

Background

The water environment pollution is one of the environmental problems of global attention, even if the input of exogenous pollutants is effectively controlled, the water body pollution state can be continued for a long time due to endogenous pollutants accumulated in the water environment all the year round, and meanwhile, the risk of releasing the endogenous pollutants accumulated in the sediment into the water is further aggravated because the bottom of the polluted water body is always in an anaerobic environment.

The sediment is also called deposit, is an important reservoir and accumulation reservoir for the pollutants entering surface water bodies such as rivers, lakes and the like, and is an endogenous source for overlying water pollution. Particularly, when exogenous pollution is effectively controlled or completely intercepted, sediment can become an important source of pollutants in surface water bodies. How to effectively control the release of endogenous pollution of natural water bodies such as lakes, reservoirs and the like becomes a scientific problem to be urgently solved in the world at present.

Eutrophication of water bodies is the most common phenomenon in a plurality of water environment problems, and especially the outbreak of algal blooms caused by the eutrophication of water bodies is an environmental problem faced by countries all over the world at present. The eutrophication of water body refers to the process that under the influence of human activities, a large amount of nutrients such as nitrogen, phosphorus and the like required by organisms enter into the slow-flow water body such as lakes, estuaries, gulfs and the like, so that algae and other plankton are rapidly propagated, the water body transparency is reduced, the dissolved oxygen amount of the water body is reduced, organic matters in the water are accumulated, and the aquatic ecological balance is destroyed. Many large lakes such as the nido lake, the Taihu lake, the Yanghu lake, the Dian lake and the West lake in China are in moderate or severe eutrophication state and frequently burst blue algae blooms, which causes serious threat and damage to the local public health and the aquatic ecological environment. In addition, eutrophication of many rivers occurs in some river sections, such as the sea river basin, the Huangpu river basin, the Zhujiang Guangzhou river section, etc., and the problems of water eutrophication and cyanobacterial bloom become important factors restricting the economic and social development of China currently and in the future for a long time.

As is well known, nutrient elements such as nitrogen, phosphorus and the like are limiting elements for water eutrophication, so that the control of the concentration of nitrogen and phosphorus in the water is also the key for controlling the occurrence of water eutrophication. The prior treatment methods of the phosphorus-containing wastewater mainly comprise traditional treatment methods such as a precipitation method, an adsorption method, a biological method and the like, and the prior art or the materials aiming at the aspect of release control of phosphorus on a substrate sludge-water interface of the eutrophic water body are less.

The existing eutrophic lake treatment technology is mainly divided into an in-situ covering treatment technology and a phosphorus fixing agent adsorption technology represented by 'Phoslock'. The in-situ covering is divided into salt covering, in-situ passivation covering and the like. In-situ covering is a relatively common substrate sludge in-situ remediation technology, but the traditional covering material only can temporarily and physically isolate substrate sludge pollutants and cannot continuously improve the anaerobic environment polluting the substrate sludge, so that the remediation effect and the time efficiency are not ideal. In addition, the pollutants in the sediments are fixed by using salts during the covering process, however, the use of the salts has the problems of poor chemical and ecological safety, great influence on organisms in the water body, public acceptance difficulty and easy secondary pollution to the water body, so that a plurality of limitations exist in the practical application. The in-situ passivation technology is to make the pollutants in the bottom sediment inert by using artificial or natural substances with passivation effect of the pollutants, so that the pollutants are relatively stable in the bottom sediment, and the release of the pollutants in the bottom sediment to a water body is greatly reduced. However, the passivation effect is influenced by the pH value and the oxidation-reduction state of the water body, and phosphorus is easily released again to cause pollution when the pH value and the oxidation-reduction state are changed. The currently internationally known phosphorus fixing agent technology of 'Phoslock' and the like covers the bottom mud by using chemically modified clay minerals of lanthanum, aluminum and the like to achieve the effect of fixing phosphorus in the bottom mud within a certain time and preventing the phosphorus from being released again, and the technology can not effectively improve the anaerobic environment polluting the bottom mud, has no effect on other pollutants except phosphorus, such as ammonia nitrogen, organic pollutants, heavy metals and the like, and has very high cost.

On the other hand, in the polluted water body, the interior of the water body is often in an anaerobic or anoxic state due to the reduction of the transparency of the water body, the decomposition and decomposition of organic matters in the bottom mud including settled algae and plant debris and the like, and the consumption of a large amount of dissolved oxygen and other adverse factors. The release problem of endogenous pollutants can be caused under the anaerobic condition, and the release of the pollutants which is relatively sensitive to oxidation reduction environment, such as phosphate, iron, manganese, sulfur and the like, is taken as the main pollutant, the water quality deterioration of the water body can be further aggravated, the water body pollution state can be continued, the eutrophication and even the outbreak of algal blooms can be accelerated, the anaerobic state of the water environment can be further worsened, and the vicious circle can be formed. The vicious circle of 'water quality deterioration-water body and bottom anaerobic-endogenous pollutant release' not only leads to the decay of aquatic animals and plants and hinders the water environment restoration effect, but also threatens the drinking water safety and human health.

However, technical bottlenecks still exist in the current market for problems of water environment bottom anaerobism, especially deepwater bottom anaerobism, sediment anaerobism and the like. The technology for improving the bottom anaerobic property commonly used in the market can be mainly divided into two modes of artificial aeration and hydraulic circulation, wherein the artificial aeration comprises a surface aeration technology and a deep aeration technology, and has the advantages of being capable of quickly improving the dissolved oxygen of the water body, but has the defect that aeration equipment consuming electric energy needs to be operated continuously or intermittently, is only suitable for smaller water bodies in practical application, is very high in cost of large-area water areas and can not be continuous, and particularly, the deep aeration often disturbs bottom mud, so that a large amount of oxygen-consuming substances in the bottom mud are re-suspended, on the contrary, the oxygen in the water body is consumed, and the dissolved oxygen is lower than that before the aeration after the aeration is stopped. The hydraulic circulation comprises a horizontal circulation mode and a vertical circulation mode, water in an area with higher dissolved oxygen can be exchanged with water in an anaerobic area to solve the problem of bottom anaerobic, but a high-power circulating water pump is often required to continuously operate, the practical application is limited by high cost, and the efficiency is not high.

How to provide a treatment material which can effectively reduce the treatment cost and energy consumption, and can exert multiple effects on treating the polluted water body to achieve the high-efficiency and environment-friendly water body remediation effect is one of the technical difficulties which need to make a breakthrough in the field at present.

Disclosure of Invention

In view of the above, the invention provides a porous adsorption material with low cost and good ecological safety, and provides an oxygen-carrying and adsorption composite functional material based on the porous adsorption material, and the oxygen-carrying and adsorption composite functional material is used for repairing a water body, so that the problems of high-efficiency adsorption of pollutants such as nitrogen and phosphorus in the water body, improvement of water body anaerobism and the like can be solved, and the porous adsorption material is low in cost and has good ecological safety.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a porous adsorption material, which is prepared by calcining a particle prepared from a modified base material at a high temperature of 600-;

the matrix material is selected from one or the combination of more than two of natural clay minerals, industrial solid wastes and activated carbon;

the concentration of the metal cation salt solution used for the impregnation modification of the matrix material is 1-5mol/L (e.g., 1mol/L, 2mol/L, 4mol/L, 5mol/L, etc.), and the pH is 5-10 (e.g., 5, 6, 8, 10, etc.);

the concentration of the alkaline solution for dipping and modifying the matrix material is 1-5mol/L (such as 1mol/L, 2mol/L, 4mol/L, 5mol/L and the like), the alkaline solution is controlled in the concentration range, better modification effect is ensured, cost can be effectively controlled, and environmental protection benefit is good.

According to the invention, cheap natural clay minerals, industrial solid wastes and/or activated carbon are used as base materials, 1-5mol/L, pH of metal cation salt solution with the pH value of 5-10 and more preferably 7-9 is used for carrying out impregnation modification, then 1-5mol/L of alkaline solution is used for carrying out impregnation modification, the obtained modified base materials are prepared into particles and then are calcined for secondary modification at the high temperature of 600-1000 ℃, and the obtained porous adsorption material has high adsorption performance on nitrogen, particularly ammonia nitrogen, and phosphorus; and the nitrogen-phosphorus composite adsorbing material is put into a water body, so that nitrogen and phosphorus in the water body can be adsorbed, nitrogen and phosphorus pollutants in the bottom sediment covered by the nitrogen and phosphorus composite adsorbing material can be adsorbed and fixed, and the risk of releasing endogenous pollutants is relieved. The release of endogenous pollutants in the sediment to the water body can be inhibited through the processes of physical isolation, chemical adsorption and the like. In addition, the porous adsorption material has good oxygen carrying performance, can be directly used for adsorbing nitrogen, phosphorus and other pollutants in a water body, and can also carry oxygen to prepare an oxygen carrying and adsorption composite functional material.

The porous adsorption material of the invention is prepared by using cheap industrial solid waste, natural clay mineral and/or activated carbon as a matrix material. Wherein the natural clay mineral is preferably selected from one or more of zeolite, bentonite and kaolin; the industrial solid waste is industrial waste material containing metal cations, such as but not limited to aluminum, iron and/or calcium ions, and the like, preferably from fly ash and/or aluminum-containing sludge, and the like; the natural zeolite contains SiO as main component₂、Al₂O₃、CaO、Na₂O、K₂O、MgO、Fe₂O₃、TiO₂The main component of the fly ash comprises SiO₂、Al₂O₃、Fe₂O₃、CaO、Na₂O、K₂O, MgO, etc. The porous adsorption material has the advantages of wide source of matrix materials, low price, no need of adding any toxic chemicals, high safety and no ecological risk to lake water. As some preferred embodiments, the matrix material is selected from the group consisting of zeolite and/or bentonite in combination with fly ash.

In some preferred embodiments, the matrix material is washed, dried and ground through a 50-150 mesh sieve, such as a 50-mesh sieve, a 100-mesh sieve, a 120-mesh sieve, a 150-mesh sieve, etc., prior to the impregnation modification with the metal cation salt solution.

In some preferred embodiments, the matrix material is a combination of zeolite and fly ash, wherein the modified matrix material forms particles having a mass ratio of modified zeolite to modified fly ash of 5:1 to 1:1 (e.g., 5:1, 3:2, 1:1, etc.). Or the matrix material is a combination of zeolite, bentonite and fly ash, wherein in the particulate matter prepared from the modified matrix material, the mass ratio of the modified zeolite to the modified bentonite to the modified fly ash is 3-6:1-3: 1-3. The modified zeolite, the modified fly ash or the modified bentonite refer to modified substances which are subjected to impregnation modification by a metal cation salt solution and impregnation modification by an alkaline solution in sequence. The preferred matrix materials have the characteristics of wider sources, lower cost, relative safety and the like.

When the impregnation modification is carried out, the concentration of the metal cation salt solution is controlled to be 1-5mol/L, the pH range is controlled to be 5-10, the pore volume of the porous adsorption material can be improved, and the material with strong adsorption and oxygen carrying performances is obtained. In order to obtain better modification effect and stronger capability of adsorbing nitrogen and phosphorus, the metal cation salt solution is preferably selected from one or a combination of more than two of aluminum chloride aqueous solution, potassium chloride aqueous solution, calcium chloride aqueous solution and ferric chloride aqueous solution, and the aluminum chloride aqueous solution is more preferably selected to achieve better and more stable phosphorus adsorption effect; the alkaline solution is preferably selected from one or more of sodium hydroxide solution, potassium hydroxide solution and calcium hydroxide solution; more preferably sodium hydroxide solution. By introducing active ions Na⁺、K⁺And/or Ca²⁺Or further introducing Al³⁺And/or Fe³⁺The cation exchange capacity of the porous adsorption material is improved, and meanwhile, when the ions exchange with the ions with large ionic radius, the internal pore channels of the material can be loosened, the pore volume of the material is increased, and the oxygen carrying performance and the adsorption capacity to nitrogen and phosphorus of the material are improved. Preferably, when the impregnation modification is performed by the metal cation salt solution, the solid-to-liquid ratio of the base material and the metal cation salt solution is 1:10-1:5 (such as 1:10, 1:8, 1:6, 1:5, etc.), the unit of the solid-to-liquid ratio is g/ml, and the impregnation time is 12-48h, such as 12h, 24h, 48h, preferably 24 h. In the impregnation modification with the alkaline solution, the solid-to-liquid ratio of the base material subjected to the impregnation modification with the metal cation salt solution to the alkaline solution is 1:10 to 1:5 (e.g., 1:10, 1:8, 1:6, 1:5, etc.), the unit of the solid-to-liquid ratio is g/ml, and the impregnation time is 12 to 48 hours, e.g., 12 hours, 24 hours, 48 hours, preferably 24 hours. By adopting the optimized impregnation modification process conditions, the better modification effect is ensured to be obtained, the pore volume of the material is improved, and the oxygen carrying performance and the adsorption performance on nitrogen and phosphorus are improved. The inventor of the application finds that if the base material is modified by the alkaline solution and then modified by the metal cation salt solution, the adsorption amount of the metal cations on the material is influenced, and the adsorption performance of the adsorption material is influenced.

The material is calcined at the high temperature of 600-; the inventor of the application finds that if the calcination temperature is less than 600-1000 ℃, the obtained material can be dispersed in water and is easy to resuspend to pollute the water. The calcination time under the high-temperature condition is preferably 1-3.5h, so that the impurities in the material can be effectively removed, the specific surface area is greatly increased, and the ammonia nitrogen and phosphorus adsorption capacity of the material is remarkably improved. In some preferred embodiments, the calcination procedure of the high temperature calcination comprises: raising the temperature from room temperature to 190-200 ℃ at a temperature raising rate of 2-10 ℃/min, and stabilizing (or maintaining) at 190-200 ℃ for 0.5-1.5 h; continuously heating to 600-1000 ℃, the heating rate is 2-10 ℃/min, and the temperature is stabilized at 600-1000 ℃ for 1-3.5 h; then the temperature is reduced to 400-500 ℃ at the speed of 2-10 ℃/min, and then the temperature is cooled to the room temperature. The calcination temperature is controlled by adopting the optimized calcination procedure, so that the service life of the modified material is prolonged, the material structure is not easy to break, the material can be used for a long time without melting, the good phosphorus release resistance control effect is still kept, and the loss on ignition is within the range of 7.3-15.4%.

The pore diameter of the porous adsorption material provided by the invention is between 2 nm and 30nm (such as 2 nm to 15nm, 2 nm to 20nm, 2 nm to 30nm, 2 nm to 40nm, 10nm to 30nm and the like); the particles have a diameter of 1-8mm, such as 1mm, 3mm, 5mm, 8mm, etc. The porous adsorption material may be irregular particles or spherical particles, and the specific shape thereof is not particularly limited, and spherical particles are more preferable. When the modified matrix material is used for preparing particles, extrusion granulation or wet granulation can be adopted.

The porous adsorption material provided by the invention has stronger oxygen carrying performance, so the invention also provides an oxygen carrying + adsorption composite functional material, the material is subjected to oxygen carrying treatment on the porous adsorption material, so that oxygen is loaded in the pore channel and the crystal structure of the porous adsorption material, the loaded oxygen is not limited in gaseous oxygen form, and can exist in structural oxygen molecules or atomic forms, such as oxygen atoms and certain sites (such as certain sites on the zeolite molecular structure) in the porous adsorption material are chemically combined.

Preferably, the composite functional material is obtained by immersing the porous adsorption material in oxygen and performing pressure swing adsorption-oxygen carrying treatment, wherein the oxygen is high-purity oxygen with the purity of more than or equal to 95% (such as 95-99%); the high-purity oxygen can be industrial oxygen or medical oxygen, is wide in source, low in price, green and environment-friendly, and has no ecological safety risk to a water environment. Further preferably, the pressure swing adsorption-oxygen carrying treatment process conditions include: the porous adsorption material is placed in a container (such as a high-pressure-resistant sealed tank), is pressurized by high-purity oxygen with the oxygen content of more than or equal to 95 percent, is stabilized (namely maintained) for 2 to 4 hours under the positive pressure condition within the pressure range of +0.05 to 0.2MPa, is vacuumized, and is stabilized for 0.5 to 1 hour under the negative pressure condition within the pressure range of-0.05 to-0.15 MPa. The optimized positive-negative pressure oxygen carrying process is convenient to operate, environment-friendly, low in cost, free of adding any chemical agent and large in temperature change, and can be carried out in batches. It is further preferable to perform the above operation of loading oxygen (i.e., repeat the above operation) in cycles under the positive pressure condition and the negative pressure condition in accordance with the process conditions of the pressure swing adsorption treatment, the number of cycles being more than 1, for example, 2, 3, 4, etc., and the preferred number of cycles being 3. In the specific implementation process, the operation of loading oxygen can be carried out in the high-pressure-resistant sealed tank, and the specific values of positive pressure and negative pressure, the cycle times and the stabilization time can be regulated and controlled according to the material difference and the number so as to regulate and control the oxygen loading amount.

The composite functional material is preferably stored in a sealed pressure-resistant container or a sealed packaging bag, and the sealed pressure-resistant container or the sealed packaging bag is preferably filled with oxygen so as to ensure the stability of the oxygen carrying performance of the material and prolong the shelf life.

The porous adsorption material provided by the invention can be directly used as an adsorption material to be applied to water body remediation, is particularly suitable for adsorbing pollutants such as nitrogen and/or phosphorus in water body and/or bottom mud and inhibiting endogenous pollutants from being released to the water body; the porous adsorption material can be applied to the water body to be restored in a spraying mode, and can be manually sprayed or mechanically sprayed, the porous adsorption material is put into the restored water body and naturally settled by means of gravity and covers the surface of bottom mud, extra energy power does not need to be consumed in the implementation process, the water ecological system is energy-saving and environment-friendly, and the natural settling process has small disturbance to the water ecological system.

The porous adsorption material provided by the invention can be further prepared into the oxygen-carrying and adsorption composite functional material, and is particularly suitable for improving the dissolved oxygen content of the water body, improving the anaerobic environment of bottom sediment, adsorbing pollutants such as nitrogen and/or phosphorus in the water body and inhibiting the release of endogenous pollutants to the water body when being applied to water body restoration. The oxygen-carrying + adsorption composite functional material is applied to a water body to be restored in a spraying mode, can be manually sprayed or mechanically sprayed, is put into the restored water body, naturally settles by means of gravity and covers the surface of bottom sediment, does not need to consume extra energy power in the implementation process, is energy-saving and environment-friendly, and has small disturbance to a water ecosystem in the natural settling process.

According to the invention, cheap natural clay minerals, industrial solid wastes and/or activated carbon are utilized, firstly, 1-5mol/L, pH is used as a metal cation salt solution with 5-10, more preferably pH value of 7-9, for impregnation modification, then, the metal cation salt solution and 1-5mol/L alkaline solution are used for impregnation modification, after the metal cation salt solution is formed into particles, the particles are calcined for secondary modification at high temperature of 600-1000 ℃, the obtained porous particle material is subjected to pressure swing adsorption and oxygen loading, then, high-concentration oxygen is loaded, and the obtained oxygen-loading and adsorption composite functional material has high adsorption performance on nitrogen, particularly ammonia nitrogen, and phosphorus; the nitrogen and phosphorus pollutants in the sediment covered by the nitrogen and phosphorus adsorption material can be adsorbed and fixed by putting the nitrogen and phosphorus adsorption material into a water body, so that the risk of releasing endogenous pollutants is relieved; more importantly, the material has higher oxygen carrying capacity and oxygen releasing capacity, and particularly, when the material is put into a water body, the material can spontaneously release oxygen carried by the material, and simultaneously, a large number of micro-nano oxygen bubbles are spontaneously formed at a solid-liquid interface, so that the dissolved oxygen of the water body can be rapidly improved, an aerobic isolation layer can be formed between a bottom sediment-water interface, and the anaerobic/anoxic environment polluting the bottom of the water body can be improved for a long time. The release of endogenous pollutants in the sediment to a water body can be inhibited through processes of physical isolation, chemical adsorption and the like, even the biogeochemical cycle process of a sediment-water interface is influenced due to the continuous improvement of an oxidation-reduction environment, the functions of in-situ remediation of the polluted environment, namely water quality improvement, water body dissolved oxygen improvement, anaerobic sediment remediation, endogenous pollutant sealing and the like can be synchronously realized through the application of the material, the long-acting remediation effect of treating the 'principal and subordinate' of the polluted water environment is really realized, and the function which cannot be realized by the prior art or the material in the field of water environment remediation is solved.

The technical scheme provided by the invention has the following beneficial effects:

(1) the invention utilizes raw materials such as natural clay mineral, industrial solid waste and/or active carbon to prepare the porous adsorption material, and in addition, the porous adsorption material can be used for preparing the composite functional material of oxygen carrying and adsorption. The obtained composite functional material not only has high adsorption performance on nitrogen and phosphorus, but also can adsorb and fix nitrogen and phosphorus pollutants in the sediment, so that the risk of releasing endogenous pollutants is reduced; simultaneously has higher oxygen carrying and releasing capacity, spontaneously forms a large number of micro-nano oxygen bubbles on a solid-liquid interface, can quickly improve the dissolved oxygen of water, but also can form an aerobic isolated layer between the bottom mud-water interface, improve the anaerobic environment at the bottom of the polluted water body for a long time, the release of endogenous pollutants in the sediment to a water body is inhibited through the processes of physical isolation, chemical adsorption and the like, even the biogeochemical cycle process of the sediment-water interface is influenced due to the continuous improvement of the oxidation-reduction environment, the material can synchronously realize the functions of in-situ remediation of the polluted water environment, namely improving water quality, improving water body dissolved oxygen, restoring anaerobic bottom mud, sealing endogenous pollutants and the like through the application of the material, and really realizes the long-acting remediation effect of treating both principal and secondary aspects of the polluted water environment, which is one of the technical difficulties to be urgently broken through in the field of water environment remediation.

(2) The oxygen-carrying and adsorption composite functional material provided by the invention has the advantages that the sources of raw materials needed by the preparation are wide, the cost is low, any toxic chemical is not needed to be added in the preparation process, the safety is high, and no ecological risk is caused to lake water bodies.

(3) According to the material disclosed by the invention, in the preparation process, the calcination temperature is controlled to be 600-1000 ℃, and the calcination time is preferably controlled to be 1-3.5h, so that impurities in the material can be more thoroughly removed, the specific surface area is greatly increased, the ammonia nitrogen and phosphorus adsorption quantity of the material is remarkably improved, the service life of the material is prolonged by controlling the calcination temperature, the material can be used for a long time, and a good phosphorus release resistance control effect is still kept.

(4) The material of the invention, in a preferred embodiment, is modified by impregnation to introduce the active ion Na⁺、K⁺、Ca²⁺Or further introducing Al³⁺、Fe³⁺The cation exchange capacity of the modified material is improved, and Na is added⁺、K⁺、Ca²⁺And Al³⁺When the ion exchange reaction is carried out with the ions with large ionic radius, the pore canals in the material can be loosened, the pore volume of the material is increased, and the oxygen carrying performance and the adsorption capacity to nitrogen and phosphorus of the material are improved.

(5) According to the material disclosed by the invention, the concentration of the salt solution used for impregnation modification is controlled to be 1-5mol/L, and the pH value is controlled to be 5-10, so that the obtained modified oxygen carrying material is large in pore volume.

(6) In the preferred scheme, the material adopts a pressure swing adsorption and positive-negative pressure oxygen carrying mode, can adopt oxygen with the purity of more than or equal to 95 percent such as industrial oxygen or medical oxygen, has wide sources, is cheap, is green and environment-friendly, and has no ecological safety risk to a water environment.

(7) The material disclosed by the invention has obvious adsorption capacity on ammonia nitrogen and phosphorus and obvious adsorption effect on ammonia nitrogen and phosphorus in sediment interstitial water, so that the material can be widely applied to the field of preparation of ammonia nitrogen and phosphorus adsorption materials, and particularly can be widely applied to the aspect of release control of ammonia nitrogen and phosphorus in a sediment-water interface.

(8) The oxygen-carrying and adsorption composite functional material provided by the invention spontaneously releases oxygen carried by the material after being put into a water body so as to improve the dissolved oxygen of the water body, simultaneously spontaneously forms a large number of micro-nano oxygen bubbles at a solid-liquid interface, continuously and slowly releases oxygen, and forms an aerobic isolation layer between a substrate sludge-water interface so as to continuously restore the anaerobic environment of the substrate sludge-water interface.

(9) The material disclosed by the invention can be applied to water environment restoration, can be mechanically or manually put into a restored water body, naturally settles by means of gravity and covers a sediment-water interface, does not need to consume extra energy power in the implementation process, is energy-saving and environment-friendly, and has small disturbance on a water ecosystem in the natural settling process.

Drawings

FIG. 1 is a graph of the isothermicity of adsorption of ammonia nitrogen by a material in one embodiment;

FIG. 2 is a graph illustrating the effect of material addition on ammonia nitrogen adsorption capacity in one embodiment;

FIG. 3 is a graph showing the effect of adsorption time of a material on ammonia nitrogen adsorption capacity in one embodiment;

FIG. 4 is a graph of the effect of ammonia nitrogen concentration on adsorption capacity in one embodiment;

FIG. 5 is an isotherm plot of phosphorus adsorption by a material in one embodiment;

FIG. 6 is a graph illustrating the effect of material dosing on phosphorus adsorption in one embodiment;

FIG. 7 is a graph of the effect of adsorption time of a material on the amount of phosphorus adsorbed in one embodiment;

FIG. 8 is a graph of the effect of phosphorus concentration on adsorption capacity in one embodiment;

FIG. 9 is O₂-a TPD detection result;

FIG. 10 is a graph of adsorption and desorption curves for different materials;

FIG. 11 is a pore size distribution curve;

figure 12 is an XRD pattern;

FIG. 13 shows the results of IR spectroscopy;

FIG. 14 is a graph showing the DO improvement effect of a material applied in situ in the field in one embodiment of the present invention.

Detailed Description

In order to better understand the technical solution of the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.

The natural zeolite, bentonite and fly ash used in the following examples are all conventional raw materials in the art, for example, zeolite can be purchased from quarries, fly ash can be obtained from coal combustion waste of power plants, and bentonite can be obtained from commercial products.

Example 1

A porous adsorption material is prepared by the following steps:

1) washing natural zeolite, bentonite and fly ash with deionized water respectively, drying at 105 ℃, grinding and sieving with a 50-mesh sieve for later use;

respectively adding the treated zeolite, bentonite and fly ash into an aluminum chloride aqueous solution, wherein the solid-liquid ratio is 1:5 (the solid unit is g, the liquid unit is ml), the concentration of the aluminum chloride aqueous solution is 1mol/L, the pH value is 8, oscillating and soaking at 95 ℃ for 24h, filtering, cooling the obtained residue, and drying; adding sodium hydroxide aqueous solution into the dried material, wherein the solid-to-liquid ratio is 1:5 (the solid unit is g, the liquid unit is ml), the concentration of the used sodium hydroxide aqueous solution is 1mol/L, oscillating and soaking for 24h, filtering, cooling the obtained solid, and drying for later use;

2) uniformly mixing the modified zeolite in the step 1), bentonite and fly ash according to a mass ratio of 5:3:1.5, and adding deionized water to prepare particles with the diameter (average particle size) of 1 mm;

3) drying the particles obtained in the step 2) at 105 ℃, then putting the particles into a muffle furnace for high-temperature calcination, wherein the temperature is raised to 200 ℃ at room temperature at a constant heating rate (2 ℃/min), and the particles are stabilized at 200 ℃ for 0.5 h; continuously heating to 600 ℃, wherein the heating rate is 2 ℃/min, and the temperature is stabilized for 1h at 600 ℃; then the temperature is reduced to 400 ℃ at the speed of 2 ℃/minute, and the porous granular material (or called porous adsorption material) is prepared after the temperature is cooled to the room temperature.

An oxygen-carrying and adsorption composite functional material is prepared on the basis of the porous adsorption material prepared in the steps 1) -3), and further comprises the following steps:

carrying out high-concentration oxygen loading treatment on the porous granular material prepared in the step 3), pressurizing with industrial oxygen with the purity of 99%, stabilizing for 2 hours under the program of pressurizing pressure plus 0.05MPa, and then vacuumizing under the pressure range of-0.05 MPa, stabilizing for 0.5 hours; the operation is circulated for 1 time, and finally the oxygen-carrying and adsorption composite functional material is prepared.

Example 2

In the embodiment, zeolite and fly ash are modified to prepare a porous adsorption material and an oxygen-carrying and adsorption composite functional material, wherein the porous adsorption material is prepared according to the following steps:

1) washing natural zeolite, bentonite and fly ash with deionized water respectively, drying at 105 ℃, grinding and sieving with a 100-mesh sieve for later use;

respectively adding the treated zeolite, bentonite and fly ash into an aluminum chloride aqueous solution with a solid-to-liquid ratio of 1:6 (g in solid unit and ml in liquid unit), wherein the concentration of the aluminum chloride aqueous solution is 2mol/L, the pH value is 8, carrying out oscillation impregnation at 95 ℃ for 24 hours, filtering, cooling the obtained residue, and drying; adding sodium hydroxide aqueous solution into the dried material, wherein the solid-to-liquid ratio is 1:6 (the solid unit is g, the liquid unit is ml), the concentration of the used sodium hydroxide aqueous solution is 2mol/L, oscillating and soaking for 24h, filtering, cooling the obtained solid, and drying for later use;

2) uniformly mixing the zeolite treated in the step 1), bentonite and fly ash according to a mass ratio of 6:3:1.5, and adding deionized water to prepare particles with the diameter (average particle size) of 2 mm;

3) and (3) drying the particles obtained in the step 2), then placing the dried particles into a muffle furnace for high-temperature calcination, wherein the procedure is that the temperature is increased to 800 ℃ at a constant rate at room temperature, the temperature increase rate is 10 ℃/min, the particles are stabilized at 800 ℃ for 3h, and the particles are cooled to room temperature to obtain the porous particle material (or called porous adsorption material).

The preparation of the oxygen-carrying + adsorption composite functional material is based on the porous adsorption material prepared in the steps 1) -3), and also comprises the following steps:

carrying out high-concentration oxygen loading treatment on the porous granular material prepared in the step 3), pressurizing with industrial oxygen with the purity of 99%, stabilizing for 2 hours under the program of pressurizing pressure plus 0.05MPa, then vacuumizing to the pressure range of minus 0.05MPa and stabilizing for 0.5 hours, and circularly operating for 1 time to finally prepare the oxygen-loading and adsorption composite functional material.

Example 3

1) washing natural zeolite, bentonite and fly ash with deionized water respectively, drying at 105 ℃, grinding and sieving with a 150-mesh sieve for later use;

respectively adding the treated zeolite, bentonite and fly ash into an aluminum chloride aqueous solution, wherein the solid-to-liquid ratio is 1:7 (solid unit is g, liquid unit is ml), the concentration of the aluminum chloride aqueous solution is 3mol/L, the pH value is 7, oscillating and soaking at 95 ℃ for 24h, filtering, cooling the obtained residue, and drying; adding sodium hydroxide aqueous solution into the dried material, wherein the solid-to-liquid ratio is 1:7 (the solid unit is g, the liquid unit is ml), the concentration of the used sodium hydroxide aqueous solution is 3mol/L, oscillating and soaking for 24h, filtering, cooling the obtained solid, and drying for later use;

2) uniformly mixing the zeolite treated in the step 1), bentonite and fly ash according to a mass ratio of 6:3:1.5, and adding deionized water to prepare particles with an average particle size of 5 mm;

3) and (3) drying the particles obtained in the step 2), then placing the dried particles into a muffle furnace for high-temperature calcination, wherein the procedure is that the temperature is raised at a constant rate of room temperature of 800 ℃, the temperature raising rate is 10 ℃/min, the particles are stabilized at 800 ℃ for 3h, and the particles are cooled to room temperature to obtain the porous particle material (or called porous adsorption material).

carrying out high-concentration oxygen loading treatment on the porous granular material prepared in the step 3), pressurizing by using industrial oxygen with the purity of 99%, stabilizing for 3 hours under the pressurizing pressure of +0.1MPa, vacuumizing under the pressure range of-0.08 MPa for 1 hour, and circularly operating for 1 time to finally prepare the oxygen-loading and adsorption composite functional material.

Example 4

1) washing natural zeolite and fly ash with deionized water respectively, drying at 105 ℃, grinding and sieving with a 100-mesh sieve for later use;

respectively adding the treated zeolite and fly ash into an aluminum chloride aqueous solution with a solid-to-liquid ratio of 1:6 (g in solid unit and ml in liquid unit), wherein the concentration of the aluminum chloride aqueous solution is 5mol/L, the pH value is 9, the aluminum chloride aqueous solution is subjected to oscillation immersion at 95 ℃ for 24 hours, filtering, cooling the obtained residue, and drying; adding sodium hydroxide aqueous solution into the dried material, wherein the solid-to-liquid ratio is 1:6 (the solid unit is g, the liquid unit is ml), the concentration of the used sodium hydroxide aqueous solution is 5mol/L, oscillating and soaking for 24h, filtering, cooling the obtained solid, and drying for later use;

2) uniformly mixing the zeolite treated in the step 1) and the fly ash according to a mass ratio of 5:2, and adding deionized water to prepare particles with an average particle size of 5 mm;

3) drying the particles obtained in the step 2), putting the dried particles into a muffle furnace for high-temperature calcination, wherein the temperature is raised to 200 ℃ at a constant heating rate (5 ℃/min) at room temperature, and the particles are stabilized at 200 ℃ for 0.5 h; continuously heating to 600 ℃, wherein the heating rate is 5 ℃/min, and the temperature is stabilized for 1h at 600 ℃; then the temperature is reduced to 400 ℃ at the speed of 5 ℃/minute, and the porous granular material (or called porous adsorption material) is prepared after the temperature is cooled to the room temperature.

loading high-concentration oxygen on the porous granular material prepared in the step 3), pressurizing by using industrial oxygen with the purity of 99%, wherein the procedure is that the pressurizing pressure is plus 0.15MPa and is stable for 3 hours, then vacuumizing, the pressure range is minus 0.08MPa and is stable for 1 hour, and circulating operation is carried out for 1 time, and finally preparing the oxygen-loading and adsorption composite functional material.

Example 5

respectively adding the treated zeolite and fly ash into an aluminum chloride aqueous solution, wherein the solid-to-liquid ratio is 1:6 (g in solid unit and ml in liquid unit), the concentration of the aluminum chloride aqueous solution is 5mol/L, the pH value is 9, the aluminum chloride aqueous solution is subjected to oscillation immersion at 95 ℃ for 24 hours, filtering, cooling the obtained residue, and drying; adding sodium hydroxide aqueous solution into the dried material, wherein the solid-liquid ratio is 1:6 (solid unit is g, liquid unit is ml), the concentration of the used sodium hydroxide aqueous solution is 5mol/L, oscillating and soaking for 24h, filtering, cooling the obtained solid, and drying for later use;

2) uniformly mixing the zeolite treated in the step 1) and the fly ash according to a mass ratio of 4:3, and adding deionized water to prepare particles with an average particle size of 1 mm;

3) and (2) drying the particles in the step 2), then placing the particles into a muffle furnace for high-temperature calcination, heating to 200 ℃ (the heating rate is 5 ℃/min), stabilizing for 1h, continuing to heat to 800 ℃, heating at the heating rate of 5 ℃/min, stabilizing at 800 ℃ for 2h, cooling to 400 ℃ at the heating rate of 5 ℃/min, and cooling to room temperature to obtain the porous particle material (or called porous adsorption material).

carrying out high-concentration oxygen loading treatment on the porous granular material prepared in the step 3), pressurizing with industrial oxygen with the purity of 99%, stabilizing for 3 hours under the program of pressurizing pressure plus 0.15MPa, then vacuumizing under the pressure range of minus 0.08MPa for 1 hour, and circularly operating for 2 times, thereby finally preparing the oxygen-loading and adsorption composite functional material.

Example 6

adding the treated zeolite and fly ash into an aluminum chloride aqueous solution respectively, wherein the solid-to-liquid ratio is 1:6 (g in solid unit and ml in liquid unit), the concentration of the aluminum chloride aqueous solution is 5mol/L, the pH value is 9, the aluminum chloride aqueous solution is subjected to oscillation immersion at 95 ℃ for 24 hours, filtering, cooling the obtained residue, and drying; adding sodium hydroxide aqueous solution into the dried material, wherein the solid-to-liquid ratio is 1:6 (the solid unit is g, the liquid unit is ml), the concentration of the used sodium hydroxide aqueous solution is 5mol/L, oscillating and soaking for 24h, filtering, cooling the obtained solid, and drying for later use;

2) uniformly mixing the zeolite treated in the step 1) and the fly ash according to a mass ratio of 3:2, and adding deionized water to prepare particles with an average particle size of 1 mm;

3) and (2) drying the particles in the step 2), putting the dried particles into a muffle furnace for high-temperature calcination, wherein the procedure is to heat the particles to 200 ℃ at room temperature (the heating rate is 5 ℃/min), stabilize the particles for 1h, continue to heat the particles to 800 ℃, heat the particles at the heating rate of 5 ℃/min, stabilize the particles at 800 ℃ for 2h, cool the particles to 400 ℃ at the heating rate of 5 ℃/min, and cool the particles to room temperature to obtain the porous particle material (or called porous adsorption material).

carrying out high-concentration oxygen loading treatment on the porous granular material prepared in the step 3), pressurizing with industrial oxygen with the purity of 99%, stabilizing for 3 hours under the program of pressurizing pressure plus 0.15MPa, then vacuumizing to the pressure range of minus 0.08MPa, stabilizing for 1 hour, and circularly operating for 3 times, thereby finally preparing the oxygen-loading and adsorption composite functional material.

Performance detection analysis

The adsorption capacity and oxygen carrying performance of natural zeolite, fly ash and the oxygen carrying + adsorption composite functional material prepared in example 6 on ammonia nitrogen and phosphorus are examined through the following experiments.

Materials (I) and (II)

Sample preparation: the four materials in the following experiments were: modified materials, which were composite functional materials, were prepared according to the method of example 6, the base material natural zeolite particles and fly ash powder used in example 6, and the pre-modified materials (which were not modified with an aqueous solution of aluminum chloride and sodium hydroxide and not subjected to calcination of step 3) and pressure swing adsorption-oxygen carrying treatment, respectively, as compared with example 6).

Ammonium stock solution: 3.8190g of high-grade pure ammonium chloride (NH) dried at 100 ℃ were weighed out₄Cl) is dissolved in ammonia-free water, the volume is determined to be 1000ml, and the solution isThe liquid contains 1mg ammonia nitrogen per milliliter; ammonia nitrogen solutions with the concentrations of 0, 10, 20, 40, 80, 120, 150, 200mg/L and the like are prepared according to the experiment requirements for later use.

Phosphorus stock solution: 0.2179g of a top-grade potassium dihydrogen phosphate (KH) dried at 100 deg.C were weighed₂PO₄) Dissolving in deionized water, and diluting to 1000ml with a constant volume, wherein the concentration of the solution is 50 mg/L; according to the experimental requirements, KH with the concentrations of 1, 2, 4, 8, 16mg/L and the like are prepared₂PO₄And (5) preparing a solution for later use.

Second, Experimental methods and results

1. Adsorption amount of Ammonia Nitrogen

1.1 adsorption isotherm

The experimental steps are as follows:

(1) respectively weighing 0.5g of natural zeolite, fly ash, a material before modification and a material after modification in a 100ml centrifuge tube, respectively adding 50ml of ammonia nitrogen solutions (0, 10, 20, 40, 80, 120, 150 and 200mg/L) with different concentration series, placing in a constant temperature oscillator, oscillating at 25 ℃ and 200rpm for 4h, then taking out the centrifuge tube, filtering through a 0.45 mu m filter membrane, and taking supernatant to determine the ammonia nitrogen concentration.

(2) According to the experimental result, the Langmuir model is used for fitting operation, the fitting result is shown in the table 1, and the maximum adsorption amount of different materials to ammonia nitrogen is obtained. The adsorption isotherm diagram of each material on ammonia nitrogen is shown in fig. 1, the abscissa "equilibrium solution concentration" in fig. 1 can also be referred to as equilibrium mass concentration, and the ordinate "ammonia nitrogen adsorption amount" is the equilibrium adsorption amount.

The Langmuir adsorption isotherm equation is expressed as follows:

ρ_e/q＝ρ_e/q_m+1/(b×q_m)

in the formula: q. q.s_m- -maximum adsorption, mg/g;

ρ_e- -equilibrium mass concentration, mg/L;

q- - -equilibrium adsorption capacity, mg/g;

b- - - -constant.

TABLE 1

From the results, the Langmuir equation has good ammonia nitrogen adsorption conformity to the material, and the correlation is higher than 0.97. From the comparison results of the four materials, the maximum adsorption capacity of the modified material reaches 8.252mg/g, and the modified material is a cheap and efficient ammonia nitrogen adsorption material.

1.2 Effect of dosing

The experimental steps are as follows:

respectively adding materials with the mass of 0.4g, 1g, 2g, 4g and 6g into a conical flask containing 200ml and 20mg/L of simulated ammonia nitrogen waste liquid (namely the previously prepared ammonium stock solution), oscillating for 5 hours at normal temperature to achieve adsorption balance, and taking supernatant to measure the adsorption capacity and adsorption rate of ammonia nitrogen.

The results are shown in FIG. 2.

As can be seen from the figure, under the same dosage, the modified material of the invention has obviously improved ammonia nitrogen adsorption amount compared with other materials. However, the adsorption capacity of the material is reduced along with the increase of the adding amount, because the effective area of the material for ammonia nitrogen adsorption is increased along with the increase of the adding amount, the unit particle adsorption is not saturated, the ammonia nitrogen amount in water is reduced, and the unit particle adsorption capacity is reduced.

1.3 Effect of adsorption time

The experimental steps are as follows:

the material with the mass of 4g is added into a conical flask containing 200ml of 5mg/L simulated nitrogen-containing waste liquid (namely the ammonium stock solution prepared in the previous step), the conical flask is vibrated at the normal temperature, and supernatant is taken for 15min, 30min, 60min, 120min, 180min and 240min to determine the adsorption capacity and the adsorption rate.

The results are shown in FIG. 3.

As can be seen from the figure, the adsorption capacity of the modified material is higher than that of other materials, the adsorption capacity of the material is remarkably increased in a short time (60min), and the adsorption capacity of the material is gradually increased to be smooth along with the increase of the adsorption time. In the time from 10min to 120min, the adsorption of the particles is from unsaturated to saturated along with the prolonging of the adsorption time, and the adsorption quantity of the particles is gradually increased; after 120min, the particle adsorption reaches saturation, the adsorption time is prolonged, and the change of the adsorption quantity is not obvious.

1.4 Effect of Ammonia Nitrogen concentration

The experimental steps are as follows:

respectively adding 4g of 4 mass materials into conical flasks containing 200ml of 2mg/L, 4mg/L, 6mg/L, 10mg/L and 20mg/L simulated nitrogen-containing waste liquid (namely the ammonium stock solution prepared in the previous step), oscillating for 5 hours at normal temperature to achieve adsorption balance, and taking supernatant to measure the adsorption capacity and the adsorption rate. The results are shown in FIG. 4.

It can be seen from fig. 4 that the modified material has higher adsorption capacity for ammonium nitrogen than other materials under different initial concentration conditions.

2. Adsorption amount of phosphorus

2.1 adsorption isotherm

The experimental steps are as follows:

(1) respectively weighing 0.5g of natural zeolite, fly ash, pre-modified material and post-modified material in 100ml centrifuge tubes, and respectively adding 50ml of KH with different concentration series₂PO₄The solution (1, 2, 4, 8, 16mg/L) was put into a constant temperature shaker at 25 ℃ and 200rpm for 4 hours, and then the centrifuge tube was taken out and passed through a 0.45 μm filter, and the supernatant was taken out to measure the phosphorus concentration.

(2) According to the experimental results, the maximum adsorption amount of the phosphorus by different materials is obtained by utilizing Langmuir model fitting operation, as shown in Table 2. The isotherm of the adsorption of phosphorus by each material is shown in fig. 5.

Wherein the Langmuir equation is as above.

TABLE 2

The Langmuir equation has better conformity to the phosphorus absorption effect of the material, and the correlation is higher than 0.997. From the comparison results of the four materials, the maximum adsorption quantity q of the modified material of the invention_mReaching 3.5233mg/g, and is a cheap and efficient phosphorus adsorption material.

2.2 Effect of dosing

The experimental steps are as follows:

respectively adding 3g, 3.5g, 4g, 4.5g and 5g of materials into a conical flask containing 200ml of 5mg/L simulated phosphorus-containing waste liquid (namely the phosphorus stock solution prepared in the previous step), oscillating for 5 hours at normal temperature to reach adsorption balance, and taking supernatant to measure the phosphorus adsorption capacity and adsorption rate.

The results are shown in FIG. 6.

From the experimental result, the unit adsorption amount of the material is continuously reduced along with the continuous increase of the adding amount; the increased mass of the material provides more active adsorption sites and active species. The modified particles have the maximum adsorption capacity of 3.5233 mg/g.

2.3 Effect of adsorption time

The experimental steps are as follows:

the material with the mass of 4g is added into a conical flask containing 200ml of simulated phosphorus-containing waste liquid (namely the phosphorus stock solution prepared in the previous step) with the mass of 5mg/L, and the conical flask is vibrated at the normal temperature, and supernatant is taken for 15min, 30min, 60min, 120min, 180min and 240min to measure the adsorption capacity and the adsorption rate.

The results are shown in FIG. 7:

from experimental results, the adsorption capacity of the fly ash calcined at 800 ℃ is relatively stable along with the change of time; the other three materials increase in adsorption amount with time; in the period from the beginning of adsorption to 2h, the slope of the curve is large, which indicates that the phosphorus absorption rate of the material is high; when the adsorption time reaches 6h, the adsorption gradually tends to be gentle and reaches the balance, and the phosphorus absorption of the material gradually reaches the saturation. The particle adsorption capacity of the composite functional material is maximum and reaches 3.5233 mg/g.

2.4 Effect of phosphorus concentration

The experimental steps are as follows:

respectively adding 4g of 4 mass materials into conical flasks containing 200ml of simulated phosphorus-containing waste liquid (namely the phosphorus stock solution prepared in the previous step) with the mass numbers of 1mg/L, 2mg/L, 4mg/L and 8mg/L, oscillating for 5 hours at normal temperature to achieve adsorption balance, and taking supernate to measure the adsorption capacity and the adsorption rate.

See figure 8 for results.

From the experimental results, as the phosphorus concentration increases, the adsorption amount of the material increases; the modified composite functional particles have the largest adsorption capacity. When the phosphorus concentration is higher, the larger the concentration difference between the solid-liquid contact surfaces of the material and the solution is, the higher the migration power of phosphate to the surface of the material is, and when the balance is finally reached, the more the amount of the phosphate adsorbed by the material is, the larger the adsorbed amount is.

3. Material characterization

To investigate the influence of the structural change of the oxygen-carrying + adsorption composite functional material on the oxygen-carrying and adsorption performances, 4 materials were subjected to temperature programmed oxidation (O)₂TPD), specific surface area and pore size distribution, XRD of different temperature sections, infrared spectrum and the like.

(1)O₂-TPD

TABLE 3

Sample (I)	Area of
		Natural zeolite particles	1.1581
Fly ash powder	0.2601
		Materials before modification	0.2825
Modified material	24.3420

O₂TPD, also known as TPO (temperature programmed oxidation), is a method for detecting the oxidation of the adsorbate or surface species on the surface of a catalyst or adsorbent by temperature programming with the introduction of oxygen.The results are shown in FIG. 9 and Table 3. At O₂In the TPD measurement, the area size of a graph formed by enclosing the signal intensity and the temperature of the horizontal axis represents the oxygen carrying capacity of the material, and the oxygen carrying capacity of the modified material is found to be greatly improved by calculating peak area comparison (see a result in a table 3).

(2) Specific surface area (BET)

The results are shown in Table 4.

TABLE 4

As can be seen from Table 4, the specific surface area and the total pore volume of the prepared composite functional material (i.e. the modified material) are remarkably improved due to the modification and calcination processes, and particularly, the specific surface area reaches 52.8595m²Is much larger than the rest of the materials.

The absorption and desorption performances of the 4 materials were also tested by a chemical absorption instrument, and the results are shown in fig. 10. The chemisorption and desorption rings formed by a chemical adsorption apparatus (Micromeritics ASAP-2020 adsorption) according to the materials show that when the relative pressure is close to the saturated vapor pressure, equilibrium is not reached, the materials (loose polymers) form slit-shaped pores, and the average pore diameter is between 2 and 30 nm; the modified material has no obvious change of the adsorption quantity along with the increase of the pressure.

Many physical properties of materials are related to the pore structure, especially the adsorption characteristics. The pore structure can influence the adsorption and transfer of the material to phosphate ions and ammonia nitrogen ions. Therefore, the pore size distribution of 4 materials was examined, and the results are shown in FIG. 11. As can be seen from the pore size distribution diagram, the modification process has little influence on micropores (100-1000nm), but has more obvious influence on micropores (<10nm) and micropores (10-100nm), and the number of micropores is obviously increased after the modification and is reduced; the modification has obvious influence on the change of the pores of the material, and the pores of the material are increased, and are most obvious. It can be seen that the pore diameter of the material before modification is about 3.5nm, and the pore diameter and the pore volume of the material after modification are changed, but the pore diameter is still 2-30 nm.

(3) XRD (X-ray diffraction)

Referring to fig. 12, it can be seen that the peaks of the natural zeolite are mainly (2 θ ═ 9.18 °, 11.14 °, 12.98 °, 22.34 °, 23.5 °, 26.82 °, 29.92 °, and 32.76 °), indicating that the main component of the zeolite is a silica-alumina. The zeolite has high silicon-aluminum content, so that the zeolite has large cation exchange capacity and is easy to adsorb ammonium ions and phosphate ions. After modification, Na is introduced⁺、Al₃ ⁺The cation exchange capacity is further increased, and finally, impurities are removed through calcination, internal pore channels are dredged, and the specific surface area is increased.

(4) Infrared spectroscopy

The results of the infrared spectroscopy of the natural zeolite particles, the fly ash powder, and the materials before and after modification are shown in fig. 13 above. 3447cm in the figure^-1And 3413cm^-1Respectively an O-H hydroxyl stretching vibration absorption peak and intermolecular hydrogen bond O-H stretching vibration; 1638cm^-1The position is a bending vibration peak of absorbed water, which shows that the zeolite has hydrophilicity; 1095cm^-1The vicinity is a stretching vibration absorption peak of Si-O in the silicon dioxide; 500-750 cm^-1Symmetric stretching vibration peaks of tetrahedron T-O-T (T is Si or Al); 420-500 cm^-1A bending vibration band in which a T-O bond is present; at the same time, the zeolite framework can adsorb water, so that the zeolite framework can be 468cm^-1A broad absorption peak of torsional vibration of physically adsorbed water was observed. Compared with the material before modification, the hydroxyl absorption peak of the material after modification is shifted to a high wave number due to the formation of hydrogen bonds and is about 3457cm^-1The absorption peak intensity is enhanced, and the absorption peak intensity of the modified material is 450-1000 cm^-1The range is significantly higher than before modification. It can be seen from the infrared spectrogram after modification that the modified material contains components of two raw materials, integrates the nitrogen absorption performance of zeolite and the phosphorus absorption performance of fly ash, and changes some radical bonds, namely, the zeolite and the fly ash react in the preparation process.

4. Improving the concentration of dissolved oxygen in water

In the field in-situ application of the composite functional material prepared in example 6 of the present invention in the post-mortuary lake, the Dissolved Oxygen (DO) concentration at the sediment-water interface is significantly increased after the material of the present invention covers the sediment surface (after) compared to before the sediment surface (before), and the monitoring results for several consecutive days show that the DO of the modified material covered the sediment surface is significantly improved compared to the DO of the control (without any treatment).

In conclusion, the oxygen-carrying and adsorption composite functional material prepared by the invention has the advantages that the specific surface area is increased and more micro-nano-sized pores are formed due to the loss of moisture and organic matter content by burning, the oxygen-carrying performance is favorably improved, and the adsorption capacity to nitrogen and phosphorus is enhanced by the introduced cationic groups and chemical structural changes after modification.

It will be appreciated by those skilled in the art that modifications or adaptations to the invention may be made in light of the teachings of the present specification. Such modifications or adaptations are intended to be within the scope of the present invention as defined in the claims.

Claims

1. A porous adsorption material is characterized in that the porous adsorption material is prepared by calcining particles prepared from a modified matrix material at the high temperature of 1000 ℃ for 1-3.5h, wherein the modified matrix material is prepared by sequentially carrying out impregnation modification on the matrix material by a metal cation salt solution and impregnation modification by an alkaline solution;

the matrix material is selected from one or the combination of more than two of natural clay minerals, industrial solid wastes and activated carbon; wherein the industrial solid waste is an industrial waste material containing metal cations;

the alkaline solution is selected from one or the combination of more than two of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution and calcium hydroxide aqueous solution;

the metal cation salt solution is selected from one or the combination of more than two of aluminum chloride aqueous solution, potassium chloride aqueous solution, calcium chloride aqueous solution and ferric chloride aqueous solution;

the concentration of the metal cation salt solution for impregnating and modifying the matrix material is 1-5mol/L, and the pH is 5-10;

the concentration of the alkaline solution for impregnating and modifying the matrix material is 1-5mol/L, the solid-liquid ratio of the matrix material subjected to impregnating and modifying by the metal cation salt solution to the alkaline solution is 1:10-1:5, the unit of the solid-liquid ratio is g/ml, and the impregnating time is 12-48 h.

2. The porous adsorbent material according to claim 1, wherein the natural clay mineral is selected from one or a combination of two or more of zeolite, bentonite and kaolin.

3. The porous adsorbent material of claim 2, wherein the metal cations in the industrial waste material containing metal cations comprise one or more of aluminum, iron, and calcium ions.

4. The porous adsorbent material according to claim 3, wherein the industrial solid waste is selected from one or more of fly ash and aluminum-containing sludge.

5. The porous adsorbent material according to any one of claims 2 to 4, wherein the matrix material is selected from one or a combination of two of zeolite and bentonite and fly ash.

6. The porous adsorbent material according to any one of claims 2 to 4, wherein the matrix material is previously washed, dried and ground through a 50-150 mesh sieve before being subjected to the impregnation modification with the metal cation salt solution.

7. The porous adsorbent material according to any one of claims 2 to 4, wherein the matrix material is a combination of zeolite and fly ash, wherein the modified matrix material is used to produce particles in which the mass ratio of modified zeolite to modified fly ash is 5:1 to 1: 1;

or the matrix material is a combination of zeolite, bentonite and fly ash, wherein in the particulate matter prepared from the modified matrix material, the mass ratio of the modified zeolite to the modified bentonite to the modified fly ash is 3-6:1-3: 1-3.

8. The porous adsorbent material according to any one of claims 1 to 4, wherein, in the modification by impregnation with the metal cation salt solution, the solid-to-liquid ratio of the base material and the metal cation salt solution is 1:10 to 1:5, the unit of the solid-to-liquid ratio is g/ml, and the impregnation time is 12 to 48 hours.

9. The porous adsorbent material according to any one of claims 1-4, wherein the calcination procedure of the high temperature calcination comprises: raising the temperature from room temperature to 190-200 ℃ at the temperature raising rate of 2-10 ℃/min, and stabilizing at 190-200 ℃ for 0.5-1.5 h; continuously heating to 600-1000 ℃, the heating rate is 2-10 ℃/min, and the temperature is stabilized at 600-1000 ℃ for 1-3.5 h; then the temperature is reduced to 400-500 ℃ at the speed of 2-10 ℃/min, and then the temperature is cooled to the room temperature.

10. The porous adsorbent material according to any one of claims 1-4, wherein the pore size of the porous adsorbent material is between 2-30 nm; the average particle size of the particles is 1-8 mm.

11. The porous adsorbent material of claim 10, wherein the particles are spherical particles.

12. An oxygen-carrying and adsorption composite functional material, which is characterized in that the composite functional material is obtained by adopting the porous adsorption material of any one of claims 1 to 11 through pressure swing adsorption-oxygen carrying treatment in an oxygen atmosphere, wherein the oxygen is high-purity oxygen with the purity of more than or equal to 95%.

13. The oxygen carrier + adsorption composite functional material according to claim 12, wherein the process conditions of the pressure swing adsorption-oxygen carrier treatment comprise: and placing the porous adsorption material in a container, pressurizing by using the high-purity oxygen, stabilizing for 2-4h under the positive pressure condition within the pressure range of + 0.05-0.2 MPa, vacuumizing, and stabilizing for 0.5-1h under the negative pressure condition within the pressure range of-0.05-0.15 MPa.

14. The oxygen carrier + adsorption composite functional material according to claim 13, wherein the pressure swing adsorption-oxygen carrier treatment is performed cyclically under the positive pressure condition and the negative pressure condition, and the number of cycles is more than 1.

15. The oxygen carrier + adsorption composite functional material according to claim 14, wherein the number of cycles is 3-4.

16. The oxygen carrier + adsorbent composite functional material according to claim 12, wherein the composite functional material is stored in a sealed pressure-resistant container or a sealed packaging bag.

17. The oxygen carrier + adsorbent composite functional material according to claim 16, wherein the sealed pressure-resistant container or the sealed package bag is filled with oxygen.

18. Use of a porous adsorbent material according to any one of claims 1 to 11 in the remediation of a body of water.

19. The use of claim 18, wherein the porous adsorbent material is used to adsorb nitrogen and/or phosphorus from a body of water or sediment to inhibit the release of endogenous contaminants into the body of water.

20. The use according to claim 19, wherein the porous adsorbent material is applied to the body of water to be remediated by spraying and over the surface of the substrate sludge.

21. The oxygen-carrying + adsorbing composite functional material as defined in claim 12 is applied to water body remediation.

22. The use of claim 21, wherein the oxygen carrier + adsorption composite functional material is used for increasing the dissolved oxygen content of the water body, improving the anaerobic environment of the bottom sediment, adsorbing nitrogen and/or phosphorus in the water body or the bottom sediment, and inhibiting the release of endogenous pollutants to the water body.

23. The use according to claim 22, wherein the oxygen carrier + adsorbent composite functional material is applied to the body of water to be remediated and covers the surface of the substrate sludge by spraying.