56 results about "Phosphorus adsorption" patented technology

The invention relates to the technical field of agricultural environment information, and discloses a rice field nitrogen and phosphorus loss amount remote regulation and control method oriented to environment data. The method comprises the following steps: acquiring historical nitrogen and phosphorus loss data, real-time meteorological data and water and fertilizer operation information of the rice field; constructing a mechanism constraint sub-model fusing nitrogen migration and transformation kinetics and phosphorus adsorption and desorption balance; performing multi-source feature extraction on the meteorological data to generate a standardized environment vector; inputting the lightweight residual convolutional neural network to output an initial prediction value; on-line fine adjustment is carried out through a Lagrangian multiplier method in combination with the mechanism model, and a corrected predicted value conforming to substance conservation is generated; and when the predicted value exceeds a threshold value, generating a drainage gate opening degree and fertilization plan adjustment instruction, and issuing the instruction to an edge terminal for execution through the narrowband Internet of Things.

The invention provides a method for removing phosphorus from a cobalt sulfate solution. The method comprises the following steps: providing a cobaltous sulfate solution to be treated; the method comprises the following steps: mixing a to-be-treated cobaltous sulfate solution, a composite polymer soluble ferric salt and a coagulant aid, carrying out precipitation reaction, and separating to obtain phosphorus-containing slag and cobaltous sulfate primary purified liquid; a deep phosphorus removal adsorbent is adopted to adsorb trace phosphorus in the cobalt sulfate primary purification liquid, then trace iron in the cobalt sulfate primary purification liquid generates precipitates in an oxygen-containing atmosphere, and after separation, a cobalt sulfate secondary purification liquid is obtained. According to the method, firstly, the synergistic effect of the composite polymer soluble ferric salt and the coagulant aid is adopted, and primary efficient removal of phosphorus is achieved; then, a deep phosphorus removal adsorbent is used for directionally adsorbing trace phosphorus in the cobalt sulfate primary purification liquid, so that deep removal of phosphorus is further realized; and finally, the residual trace iron is precipitated and separated in the oxygen-containing atmosphere, so that the purity of the secondary purified cobalt sulfate liquid is further guaranteed.

The present application relates to the field of dephosphorization adsorbent, disclose a kind of modified hydrotalcite adsorbent and its preparation method and application, the adsorbent includes hydrotalcite and / or hydrotalcite-like compound with lamellar structure, and modification component;The modification component includes the first metal component modified on the layer of the hydrotalcite and / or hydrotalcite-like compound, and the second metal component modified in the interlayer of the hydrotalcite and / or hydrotalcite-like compound;Wherein, the first metal component is selected from transition metal and / or rare earth metal;The second metal component is selected from at least one of alkali metal.By metal modification in the layer and interlayer of hydrotalcite and / or hydrotalcite-like compound, the selectivity of adsorbent for phosphate in water can be effectively improved, and the phosphorus capacity is high, and has excellent effect in the application of dephosphorization in complex water.

This invention discloses a precision treatment system and control method for farmland non-point source phosphorus pollution based on enrichment and reuse, comprising a water control unit, a purification unit, a desorption unit, and a power supply unit; the purification unit is installed inside the water control unit, and the desorption unit is connected externally to the water control unit; the water control unit is used for water flow control; the purification unit is used to purify farmland non-point source polluted water, and the purification unit includes directional phosphorus adsorption matrix filler, which is lanthanum-based coated molecular spheres and lanthanum-based coated molecular bricks; the desorption unit is used to perform desorption when the phosphorus adsorption capacity of the purification unit is saturated; the power supply unit is used to supply power to the system; thus, precision treatment of farmland non-point source phosphorus pollution based on enrichment and reuse is achieved.

The invention discloses a magnesium-doped calcium carbonate adsorbent and a preparation method and application thereof, the chemical formula of magnesium-doped calcium carbonate is as shown in the following formula (1): MgxCa1-x (CO3), x represents the molar ratio of magnesium to calcium, 0 lt; xlt; and 0.200%. Compared with pure calcium carbonate, the adsorption rate of the adsorbent based on the magnesium-doped calcium carbonate material provided by the invention is greatly improved, so that passivation of the pure calcium carbonate in the early stage of adsorption is relieved. Under the condition of the same phosphorus adsorption amount, the adsorption rate of the adsorbent is obviously improved. Alternatively, under the same adsorption time, the phosphorus adsorption amount of the adsorbent provided by the invention is obviously improved. The adsorbent provided by the invention has good adsorption selectivity (competitive ion interference resistance), so that the adsorbent has high practical application value. In addition, as the preparation is simple and convenient and the cost is low, the compound can be used as an agricultural fertilizer slow-release agent, can maintain the phosphorus content in farmland for a long time, and is more beneficial to the growth of crops.

The invention belongs to the technical field of industrial and agricultural waste recycling, and particularly relates to a method for recycling biogas slurry nutrients by mechanically and chemically activating anaerobic biogas residue biochar. According to the method, magnesium oxide desulfurization residues and oxalic acid are used as grinding aids, and biochar is activated by using a mechanochemical technology, so that the content of water-soluble phosphorus in the biochar is increased, and the water-soluble phosphorus is used as a phosphorus source of an MAP reaction. Meanwhile, Mg < 2 + > in MDWR provides a magnesium source for MAP reaction. The particle size of the activated biochar is reduced, the specific surface area is increased, the activated biochar can be used as a seed crystal to accelerate struvite crystal formation, and the nitrogen and phosphorus adsorption performance is improved by increasing the specific surface area; and finally, synergistically recovering nitrogen and phosphorus nutrients in the biogas slurry through MAP chemical precipitation and physical adsorption of activated biochar. According to the method, the process for recycling the biogas slurry nutrients by using the mechanochemical activated charcoal is obvious in recycling effect. The problem of disposal of two wastes of biogas slurry and biogas residue in an agricultural pig farm is solved, and an innovative process is provided for resource utilization of industrial and agricultural wastes.

The invention discloses a phosphorus-loaded catalyst regeneration waste liquid recovery treatment method and a phosphorus-loaded catalyst regeneration waste liquid recovery treatment device, and aims to better control the acidity of a regeneration liquid so as to maintain the service life of a phosphorus-loaded catalyst and realize the cyclic utilization of the regeneration liquid and the reduction concentration of phosphorus resources. And the treatment difficulty of the regenerated waste liquid can also be reduced. Comprising the following steps: introducing the phosphorus-loaded catalyst regeneration waste liquid into an adsorption device filled with a regeneration waste liquid dephosphorization adsorbent, separating a phosphorus component in the phosphorus-loaded catalyst regeneration waste liquid, collecting an effluent as a phosphorus-poor regeneration liquid, and recycling the phosphorus-poor regeneration liquid for regeneration of the phosphorus-loaded catalyst, after the regeneration waste liquid dephosphorization adsorbent is saturated in adsorption, hot water is adopted as a desorption medium to replace the stored liquid in the adsorption device, the volume of the desorption medium is controlled to be smaller than the volume of the phosphorus-carrying catalyst regeneration waste liquid capable of being contained in the adsorption device, and the regeneration waste liquid dephosphorization adsorbent is eluted.

The present application relates to the field of agricultural environmental information technology, and discloses a remote control method for nitrogen and phosphorus loss amount of paddy field facing environmental data. The method comprises the following steps: obtaining historical nitrogen and phosphorus loss data, real-time meteorological data and water and fertilizer operation information of the paddy field; constructing a mechanism constraint sub-model combining nitrogen migration and transformation dynamics and phosphorus adsorption and desorption balance; performing multi-source feature extraction on the meteorological data to generate a standardized environmental vector; inputting the light residual convolutional neural network to output an initial prediction value; combining the mechanism model to generate a corrected prediction value conforming to the conservation of mass through the Lagrange multiplier method; when the prediction value exceeds the threshold value, generating a drainage gate opening degree and a fertilizer plan adjustment instruction, and delivering the instruction to an edge terminal for execution through a narrowband Internet of Things.

The invention discloses a La-Fe bimetal organic framework derived heterojunction material anode and a preparation method and application thereof, and belongs to the technical field of phosphorus adsorption materials. The preparation method of the La-Fe bimetal organic framework derived heterojunction material comprises the following steps: (1) mixing ferric salt, lanthanum salt, terephthalic acid and an organic solvent, and carrying out solvothermal reaction to obtain a La-Fe bimetal organic framework precursor material; and (2) carrying out calcination derivation on the La-Fe bimetal organic framework precursor material in an inert atmosphere to obtain the La-Fe bimetal organic framework derived heterojunction material. The preparation method is simple and low in cost, and the prepared La-Fe bimetal organic framework derived heterojunction material anode has the advantages of being high in adsorption capacity, high in adsorption rate, high in selectivity, wide in pH application range and the like on phosphate.

The application discloses a phosphorus-carrying catalyst regeneration waste liquid recycling treatment method and device, and aims to solve the technical problem of how to better control the acidity of the regeneration liquid to maintain the service life of the phosphorus-carrying catalyst, realize the recycling of the regeneration liquid and the concentration reduction of the phosphorus resource, and reduce the treatment difficulty of the regeneration waste liquid. The method comprises the following steps: introducing the phosphorus-carrying catalyst regeneration waste liquid into an adsorption device filled with a regeneration waste liquid phosphorus removal adsorbent, separating the phosphorus component in the phosphorus-carrying catalyst regeneration waste liquid, collecting the effluent as a phosphorus-lean regeneration liquid, recycling the phosphorus-lean regeneration liquid for the regeneration of the phosphorus-carrying catalyst, and mainly using the phosphate as the phosphorus component; when the regeneration waste liquid phosphorus removal adsorbent is saturated, hot water is used as a desorption medium to replace the liquid in the adsorption device, the volume of the desorption medium is controlled to be less than the volume of the phosphorus-carrying catalyst regeneration waste liquid that can be contained in the adsorption device, and the regeneration waste liquid phosphorus removal adsorbent is eluted.

The invention relates to the technical field of sewage treatment, and discloses an artificial wetland and a carbon source intelligent regulation and control method thereof. The constructed wetland comprises an artificial medium composite layer, a carbon source regulation and control mechanism, a water inlet mechanism and a water outlet mechanism. The artificial medium composite layer comprises a diversion layer, a reaction layer and a precipitation layer which are sequentially arranged from top to bottom, the reaction layer is provided with a mounting module, and a carbon source is arranged in the mounting module; the carbon source regulation and control mechanism comprises a carbon source storage device, an extraction device and a conveying device, one end of the conveying device is connected with the carbon source storage device, and the other end is connected with the mounting module; the water inlet mechanism is connected with the diversion layer; the water outlet mechanism is connected with the precipitation layer. A carbon source is provided for the mounting module through the carbon source regulation and control mechanism, and the carbon source is sufficient when the artificial medium composite layer treats sewage. The carbon source regulation and control mechanism can control and regulate the supply speed of the carbon source, can control the denitrification process to be efficiently carried out, inhibits the phosphorus adsorption saturation phenomenon, and is higher in nitrogen and phosphorus removal efficiency of the constructed wetland.

The invention discloses an integral phosphorus removal adsorbent based on a fibrous inorganic mineral material, a preparation method of the integral phosphorus removal adsorbent and application of the integral phosphorus removal adsorbent to removal of phosphorus in an aqueous solution. According to the invention, a fibrous inorganic mineral material with the size of more than centimeter level is used as a carrier, a non-noble metal salt is used as a precursor, non-noble metal hydroxide is formed through in-situ deposition, and the non-noble metal hydroxide is uniformly attached to the surface of the fibrous inorganic mineral material, so that the integral phosphorus removal adsorbent is directly obtained without further molding. The preparation process is simple, the material source is wide, the cost is low, and large-scale preparation is easy. The obtained adsorbing material can effectively remove trace phosphorus in water, has high phosphorus removal capacity and rapid adsorption kinetics, can realize an excellent treatment effect in a wide concentration and pH range, and can be recycled.

The invention discloses an iron / calcium modified chlorella biochar material for removing phosphorus from mariculture tail water, which comprises chlorella biomass powder, a Fe source, a Ca source and polyethylene glycol 4000, and nitrogen is used as a protective gas in the preparation process. The catalyst is prepared through the steps of chlorella biomass pretreatment, Fe / Ca impregnation liquid preparation, biomass impregnation and pretreatment, anaerobic pyrolysis and the like, the porous structure and the positive electricity surface of the catalyst can strengthen phosphorus adsorption, and phosphorus is removed through the synergistic effect of electrostatic adsorption, ligand exchange, chemical precipitation and physical interception; when the pH value is 3-11 and the salinity is 5-40 per thousand, the phosphorus removal efficiency is high. When in use, the phosphorus removal rate of the tail water reaches 93% or above, the tail water tends to be saturated within 4 hours, the phosphorus concentration of the treated tail water can meet the first-grade discharge standard of 0.5 mg / L or below, meanwhile, resource utilization of the chlorella breeding waste is achieved, additional transfer treatment materials are not needed, and the operation cost and time are saved.

The utility model discloses a denitrification deep bed filter, which comprises a filter body, a filter material layer and a water distribution system, the filter material layer is composed of alternately stacked composite biological filter material modules, and the water distribution system comprises a multi-stage rotational flow water distribution structure and a turbulent flow strengthening unit. Through alternately stacked composite biological filter material modules and a multi-stage rotational flow water distribution structure, in combination with a turbulent flow strengthening unit and a precise carbon source adding system, the problems of limited nitrogen and phosphorus removal efficiency, high energy consumption and poor water quality adaptability of a traditional process are solved. The active coke layer improves SS interception and biological membrane enrichment capability, and the volcanic rock coating enhances phosphorus adsorption; the hydrodynamic mixing efficiency is enhanced through rotational flow water distribution and baffling gradient pore design, and the utilization rate of a carbon source is increased by 15% in cooperation with dynamic carbon-nitrogen ratio control. Therefore, the stable advanced treatment effect that the effluent TN is smaller than or equal to 12 mg / L, the TP is smaller than or equal to 0.5 mg / L and the SS is smaller than or equal to 10 mg / L is achieved, the energy consumption of the system is reduced to 0.28 kWh / m, the backwashing period is prolonged by 34% 4, and the comprehensive advantages of efficient nitrogen and phosphorus removal, low operation cost and high working condition adaptability are achieved.

Provided in the present application are a phosphorus adsorption material, and a preparation method therefor and the use thereof. The phosphorus adsorption material comprises a porous composite material, wherein the porous composite material comprises porous biomass carbon and polymer fibers at least partially wound around the porous biomass carbon; and the porous composite material contains several amino groups, at least some of which bind to iron ions. Moreover, the phosphorus adsorption material satisfies the following conditions: 0.36 nm≤d002≤0.43 nm, 0.85≤ID / IG≤1.38, B≥240 m2 / g, and 0.20 cm3 / g≤V≤0.56 cm3 / g, wherein d002 represents the interlayer spacing of graphite-like microcrystallites in the phosphorus adsorption material; B represents the specific surface area of the phosphorus adsorption material; and V represents the total pore volume of the phosphorus adsorption material. The phosphorus adsorption material provided in the present application has a high theoretical adsorption capacity for a phosphorus-containing water body having a high or low phosphorus concentration, and can be regenerated and reused.

The present application belongs to the field of spectral analysis and intelligent detection technology, and discloses a soil available phosphorus content hyperspectral imaging rapid detection method and system. The method sequentially performs adaptive baseline correction, target-oriented orthogonal signal correction combined with fractional order differential transformation phosphorus response enhanced multi-order feature extraction, sparse Bayesian sensitive band selection based on mutual information graph Laplace regularization, multi-scale hollow causal convolution regression network prediction of phosphorus adsorption state perception, and temperature and humidity environment compensation correction fused with Kubelka-Munk diffuse reflection theory physical constraints. The physical reasonableness of shared coding features is constrained by bidirectional cross-attention fusion of spectral and spatial features and phosphorus adsorption state classification auxiliary task, and the available phosphorus content, confidence interval and adsorption state type judgment result are output.

The invention belongs to the technical field of red mud solid waste utilization, and particularly discloses a method for preparing a magnetic targeted phosphorus removal material through red mud in-situ crystallization and application of the magnetic targeted phosphorus removal material. The phosphorus removal material provided by the invention is prepared from the following raw materials in parts by mass: 85 to 95 parts of red mud, 10 to 20 parts of water and 1 to 4 parts of glucose. The phosphorus removal material has a composite structure of Fe3O4 magnetic core + Al (OH) 3 adsorption layer + SiO2 skeleton, has high phosphorus removal capacity and high magnetic saturation intensity, can still obtain better phosphorus removal performance after adsorption saturation through simple regeneration treatment, can be repeatedly used for 5-8 times at most, and greatly reduces the operation cost. The invention also provides a preparation method and application of the phosphorus removal material, the preparation process does not need high-temperature roasting, does not need additional addition of a magnetic reagent and an acid-base modifier, only utilizes the strong basicity of the red mud and iron and aluminum components, and takes glucose as a mild reducing agent to generate a composite structure of a magnetic core and a phosphorus removal adsorption layer in situ.

The invention belongs to the technical field of environmental pollution abatement and recycling, and particularly relates to a multi-metal composite modified charcoal phosphorus adsorption material, a preparation method, a device and application, the adsorption material is prepared from the following raw materials by mass percent: 40%-75% of charcoal, 10%-25% of bentonite, 5%-15% of light magnesium oxide, 5%-15% of anhydrous and 1%-8% of ferric trichloride hexahydrate. And 0.5%-5% of zirconium oxychloride octahydrate. The preparation method comprises the following steps: uniformly mixing the raw materials, calcining and the like to prepare the granular filter material, and the phosphorus adsorption capacity of the filter material can reach 50-80mg / g. After adsorption saturation, the filter material rich in nutrient elements such as phosphorus, calcium, magnesium and iron can be directly applied as an agricultural slow-release fertilizer and a soil conditioner, so that resource utilization of pollutants is realized, and the filter material has multiple advantages of efficient phosphorus adsorption, soil improvement and resource recovery and has remarkable economic and environmental benefits.

The invention belongs to the technical field of water treatment, and particularly relates to a rare earth element doped ferrihydrite adsorbent with the surface modified with betaine and a preparation method and application thereof.The adsorbent takes the rare earth element doped ferrihydrite as a matrix, the surface of the ferrihydrite is modified with betaine molecules, and an organic-inorganic hybrid structure is formed; at least one rare earth element is doped in the ferrihydrite, and the doping amount of the rare earth element in the ferrihydrite is 0.5-20wt%; the mass percentage of the betaine molecules in the adsorbent is 1-20wt%. Compared with the prior art, the invention solves the problem that the phosphorus adsorption material in the prior art is difficult to give consideration to high adsorption capacity, high selectivity, good dispersibility and long-term stability at the same time. According to the scheme, rare earth doping and betaine surface modification are combined to synergistically realize comprehensive improvement of the adsorption capacity, selectivity and complex water body interference resistance of the adsorbent on phosphate.

The invention discloses an urban sewage treatment device and process based on resource and energy recovery. The device comprises a coagulating sedimentation unit, a nitrogen and phosphorus adsorption unit, a biological filter unit, a sludge anaerobic digestion unit, a sewage source heat pump unit, a sludge concentration unit, a digested sludge resource recycling unit, a flocculant dosing tank, a first sewage adjusting tank and a second sewage adjusting tank. The coagulating sedimentation unit captures organic matters and changes the carbon flow direction, the sludge anaerobic digestion unit recovers chemical energy in sewage, and the nitrogen and phosphorus adsorption unit efficiently recovers nitrogen and phosphorus resources in the sewage. The synergistic effect that the digested sludge resource recycling unit recycles iron and phosphorus resources in digested sludge and the sewage source heat pump unit recycles tail water waste heat is achieved, and efficient removal of pollutants and efficient recycling of nitrogen, phosphorus and iron resources and energy are achieved. Therefore, the problems of high energy consumption, high material consumption and waste caused by the fact that resources and energy in sewage and sludge are not effectively recycled in the traditional town sewage treatment process at present are solved.

The present application relates to sewage treatment technical field, disclose a kind of artificial wetland and its carbon source intelligent control method.Artificial wetland includes: artificial medium composite layer, carbon source control mechanism, water inlet mechanism and water outlet mechanism.Artificial medium composite layer includes flow guide layer, reaction layer and sediment layer which are sequentially arranged from top to bottom, and reaction layer is provided with installation module, and carbon source is arranged in installation module;Carbon source control mechanism includes: carbon source storage device, extraction device and conveying device, one end of conveying device is connected with carbon source storage device, the other end is connected with installation module, and extraction device is arranged in conveying device;Water inlet mechanism is connected with flow guide layer;Water outlet mechanism is connected with sediment layer.The present application provides carbon source to installation module by carbon source control mechanism, and carbon source is sufficient when artificial medium composite layer is treated to sewage.Carbon source control mechanism can control the supply speed of adjusting carbon source, can control denitrification process to carry out efficiently, inhibit phosphorus adsorption saturation phenomenon, and the efficiency of artificial wetland denitrification and phosphorus removal is higher.

The invention discloses a preparation method and application of a porous adsorbent, and the preparation method of the porous adsorbent comprises the following steps: adding a modifier into clay ore under supercritical condition, centrifuging, washing with water, drying, grinding, sieving, and washing with water to obtain the porous adsorbent. The adsorption method of the porous adsorbent in phosphorus adsorption comprises the following steps: mixing the porous adsorbent, KCl and water, performing ultrasonic treatment for multiple times, stirring, and adding a pH regulator until the pH regulator is weakly acidic to obtain an adsorbent suspension; under the protection of nitrogen, the adsorbent suspension in the step T1 and a KH2PO4 solution are ultrasonically mixed to be uniform, the pH is adjusted to be weakly acidic, stirring, oscillating, centrifuging and filtering are conducted, and the dephosphorized adsorption sample is obtained. The clay minerals are modified by formic acid, oxalic acid and citric acid under the supercritical condition, for example, compared with constant-temperature oscillation of an oxalic acid aqueous solution under the supercritical condition, the phosphorus adsorption capacity is improved by 72.07%. The method has a good application prospect in the aspect of phosphorus pollution control.

To provide a technique for facilitating the treatment of an adsorbent after the adsorption of phosphorus or heavy metals while developing excellent phosphorus adsorbing capacity.SOLUTION: Provided are an adsorbent containing a polyurethane and a powder pH-adjusted iron precipitate having a powder pH of 3 or more, in which the powder pH-adjusted iron precipitate is contained in the adsorbent at a mass ratio of 65% or more, and related techniques thereof.SELECTED DRAWING: None

The present invention provides an anodic oxide coating film on which a pore-sealing treatment can be performed when forming the anodic oxide coating film on aluminum or an aluminum alloy, and from which a pore-sealed coating film having excellent thermal crack resistance is formed by performing the pore-sealing treatment on the anodic oxide coating film. The present invention also provides: an anodic oxidation treatment liquid from which said anodic oxide coating film can be formed, and from which a pore-sealed coating film having excellent thermal crack resistance is formed by performing a pore-sealing treatment on said anodic oxide coating film; and an anodic oxidation treatment method using said anodic oxidation treatment liquid.　The present invention provides an anodic oxide coating film characterized in that the amount of phosphorus adsorbed on the surface thereof after being subjected to a pore-sealing treatment is 0.1-4.0 at%.

The invention provides an autotrophic-heterotrophic synergistic nitrogen and phosphorus removal method. The method comprises the following steps: providing a reactor filled with active hematite; the method comprises the following steps: carrying out biofilm culturing on a mixed bacterial liquid containing a heterotrophic denitrification strain and an autotrophic denitrification strain on a reactor filled with active hematite; introducing a nitrogen and phosphorus-containing water body to be treated into the reactor to realize nitrogen and phosphorus removal; wherein in the nitrogen and phosphorus removal reaction process, the active hematite adsorbs phosphorus in the to-be-treated water body, and meanwhile, the heterotrophic denitrification strains and the to-be-treated water body are promoted to be subjected to a denitrification reaction to realize nitrogen removal; and the cytochrome c generated in the denitrification reaction process is used as an electron donor to promote the nitrogen removal of the autotrophic denitrification strain through the denitrification reaction.

This invention relates to the field of water pollution catalytic treatment technology, and particularly to a zirconium-modified nitrogen-doped biochar based on chemical oxidation, its preparation method, and its application. By nitrogen doping, zirconium modification, and hydrogen peroxide oxidation of the biochar, and by controlling the carbonization temperature, nitrogen source doping ratio, and hydrogen peroxide oxidation treatment conditions, a structurally stable modified biochar material with sufficient nitrogen doping and good zirconium species dispersion is obtained. This material can achieve a near 100% removal rate of high-concentration phosphorus, solving the problems of low phosphorus adsorption efficiency and complex preparation processes of existing biochars, and providing a new solution for achieving green and efficient phosphorus removal.

A method for preparing a phosphorus adsorbent, including: drying a waste gypsum to remove moisture; crushing and sieving an obtained dried gypsum to obtain a crushed gypsum; subjecting the crushed gypsum to pyrolysis in an inert gas atmosphere to obtain a pyrolysis product; and grinding and sieving the pyrolysis product to obtain the phosphorus adsorbent; wherein based on a total weight of the waste gypsum, the waste gypsum includes less than 47 wt % of SO3, more than 45 wt % of CaO, and less than 1 wt % of Al2O3. Also provided is a phosphorus adsorbent prepared by the method.

A nitrogen and phosphorus adsorption unit, device, treatment system, and method for fish farming wastewater belong to the field of wastewater purification in aquaculture. It includes two vertical pipes with open tops and perforated surfaces. Between the two vertical pipes, several support pipes with perforated surfaces are distributed along the vertical direction. Each support pipe has two ends connected to the interior of the vertical pipe and contains several adsorption balls connected in series by connecting lines. Each adsorption ball is filled with bentonite and has several perforated surfaces. This invention achieves rapid replacement of the adsorption material by filling the adsorption balls with bentonite and using connecting lines to connect them. The perforations on the support pipes and the perforations on the adsorption balls allow for seepage contact between the wastewater and the bentonite, effectively preventing bentonite loss. Furthermore, the connecting lines allow for the removal of adsorption balls from the support pipes and replacement with new ones.

The invention discloses a layered double hydroxide-polyvinyl chloride flexible composite film as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing layered double-metal hydroxide powder and a solution containing polyvinyl chloride, transferring the mixture to a supporting plate, spreading, immersing the supporting plate into a water-soluble polar solvent, and carrying out solvent exchange, so that the polyvinyl chloride is separated out and cured; the layered double hydroxide-polyvinyl chloride flexible composite film is prepared; wherein the K value of the polyvinyl chloride is not higher than 59; in the solution containing the polyvinyl chloride, the mass concentration of the polyvinyl chloride is 0.05-0.2 g / mL. The prepared composite film has excellent phosphorus adsorption performance and is easy to recover, the preparation method is simple, the cost is low, and large-scale production is facilitated.

The invention relates to a nitrogen and phosphorus high-value recovery method suitable for high-nitrogen and high-phosphorus sewage. Specifically, iron-rich biochar obtained by pyrolyzing urban iron-rich sludge is taken as a carrier, Fe (III) in the biochar is partially reduced into Fe (II) by iron reducing bacteria in an anaerobic stage, and a nanoscale Fe3O4 magnetic nucleus is generated through induction; then switching to an aerobic stage, and synergistically finishing efficient nitrogen and phosphorus adsorption by utilizing microbial metabolism and iron-rich biochar; the iron-rich biochar saturated by adsorption is subjected to alkali liquor desorption and struvite crystallization to recover nitrogen and phosphorus, and the regenerated iron-rich biochar can be directly reused. The method is operated under the conditions of normal temperature, normal pressure and 0.1-0.5 T of a magnetic field, the recovery rates of nitrogen and phosphorus are both greater than or equal to 92%, and the saturation magnetization intensity is kept gt after the magnetic carbon is circulated for 50 times; 90%. The problems of sludge recycling, sewage nitrogen and phosphorus removal, high magnetic separation energy consumption, difficult adsorbent regeneration and the like are synchronously solved, and the method has the advantages of greenness, low carbon, high resource value, low operation cost and the like.