132 results about "Struvite" patented technology

The invention relates to the field of sludge treatment, and particularly discloses a method for recycling phosphorus in sludge pyrolysis residues, a flocculant synthesis method and application. The invention discloses a method for recovering phosphorus in sludge pyrolysis residues. The method comprises the following steps: drying the sludge pyrolysis residues, grinding and sieving; the sludge pyrolysis residues are put into a hydrochloric acid solution to react, and solid-liquid separation is carried out after the reaction; treating the phosphorus-containing extracting solution through adsorption resin to obtain a phosphorus purification solution; adjusting the pH value of the phosphorus purification liquid to 9-11, and carrying out a crystallization reaction under the condition that the molar ratio of magnesium to nitrogen to phosphorus is (0.8-1.2): (1-1.6): 1 to obtain struvite; a synthetic method of the flocculating agent is as follows: the flocculating agent is prepared from residual sludge residues. The method for recycling phosphorus in the sludge pyrolysis residues has the advantages that phosphorus resources are recycled from the sludge pyrolysis residues, and the residues are secondarily utilized. The flocculating agent is applied to municipal sewage treatment.

The invention belongs to the technical field of magnesium desulfurization wastewater treatment, and particularly relates to a magnesium desulfurization wastewater ammonia nitrogen and heavy metal ion cooperative treatment system which is characterized by comprising a vertical flow sedimentation tank, a stirring reaction device and a cyclone separator, and an outlet of the vertical flow sedimentation tank is connected with an inlet of the cyclone separator through a material transfer pipeline; a bottom outlet of the cyclone separator is connected with a stirring reaction device, the stirring reaction device is connected with an inlet of the vertical flow sedimentation tank through a seed crystal pump and a seed crystal pipeline, the stirring reaction device is connected with an automatic phosphate dosing feeder, the bottom of the stirring reaction device is connected with a blow-off pipeline through an automatic blow-off valve, and the treated desulfurization wastewater enters a downstream sewage treatment plant or is subjected to slag flushing. The method has the advantages that denitrification efficiency is high, reaction is stable, ammonia nitrogen and heavy metal ions in the magnesium desulfurization wastewater are synergistically removed, separated magnesium ammonium phosphate (struvite) precipitate crystals are used as seed crystals to return and adsorb, excessive addition of phosphate agents is reduced, and the effect of mixed reaction can be guaranteed.

The wastewater treatment system comprises a water inlet unit, a reactor, a separation unit and a circulation unit which are sequentially connected to form a closed-loop system, the water inlet unit is further connected with a chemical dosing unit, the water inlet unit is used for conveying wastewater to the reactor, and the chemical dosing unit is used for adding alkali into the wastewater to adjust the pH value and providing required magnesium ions; a fluidization reaction zone and a separation zone are arranged in the reactor, and the fluidization reaction zone promotes generation and growth of struvite particles through particle collision and aggregation; the separation zone enables generated particles to partially fall back to the fluidization reaction zone for continuous reaction through preliminary solid-liquid separation; the separation unit is used for receiving the wastewater in the separation area, further removing residual particles, and enabling the small particles to flow back to the reactor through the circulation unit for recycling. By optimizing the particle generation, separation and backflow processes in wastewater treatment, the formation of target large particles is promoted, the resource recycling is facilitated, meanwhile, the consumption of chemical agents is reduced, and the cost is reduced.

The invention belongs to the technical field of wastewater treatment, and relates to a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate. The technical problems that in the prior art, the removal effect of high-concentration ammonia nitrogen and organic pollutants in landfill leachate is poor, the follow-up biochemical treatment effect is limited, and a biochemical treatment system is prone to being subjected to huge impact are solved. The invention provides a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate. The method comprises the following steps: carrying out struvite crystallization reaction on the landfill leachate; carrying out solid-liquid separation after gravity settling to obtain upper liquid and crystals; the pH value of the upper liquid is adjusted to 2.0-3.0, Schwertmannite and H2O2 are added, the adding amount of the Schwertmannite is 2-20 g / L, V (H2O2) / m (Schwertmannite) is 0.25-5 mL / g, a photocatalytic reaction is conducted at the constant temperature, a photocatalytic reaction solution is obtained and filtered, and the photocatalyst is obtained. According to the method, ammonia nitrogen and organic pollutants are greatly removed in advance before the landfill leachate is subjected to biochemical treatment, so that the biodegradability of the landfill leachate is improved, the impact load of biochemical treatment is reduced, and the whole process flow is simplified.

The invention discloses an ecological slope protection material, system and method based on struvite biomineralization technology.The ecological slope protection material comprises a slope stabilization material and a vegetation matrix, the slope stabilization material is composed of an enzyme-induced phosphate precipitation reaction solution and an enzyme-induced carbonate precipitation reaction solution, and through the synergistic effect of the two biomineralization technologies, the slope stabilization material can be used for slope protection. A biological mineralization reaction occurs in the side slope to generate struvite, magnesium carbonate and other minerals, so that side slope tailing sand reinforcement and heavy metal stabilization are realized, and slow-release nutrition is provided for plant growth. The invention further constructs a multi-layer slope protection system comprising a slope lattice beam, an in-situ remediation area, a slope drainage layer and a slope vegetation layer, and the multi-layer slope protection system is achieved through a construction method combined with a special grouting-sprinkling irrigation device. And finally, integrated safety reinforcement and ecological regreening of the side slope of the heavy metal tailings pond are achieved.

The invention discloses a pulse electrochemical crystallization coupled composite constructed wetland system which comprises an energy system, a pulse electrochemical crystallization pond and a composite constructed wetland system, and the energy system supplies energy to the pulse electrochemical crystallization pond and the composite constructed wetland system. Aquaculture wastewater firstly enters a pulse electrochemical crystallization pond, struvite (MAP) sediment is formed through electrochemical crystallization, ammonia nitrogen and phosphate in the wastewater are efficiently removed, and partial removal of organic matter is achieved. Then the wastewater enters a composite artificial wetland system, and the wastewater is deeply purified under the action of filler filtration / adsorption, microbial assimilation / conversion and plant absorption. The pulse electrochemical crystallization coupled composite constructed wetland system is compact in structure, and the defects of high energy consumption of direct-current electrochemical crystallization and low purification efficiency of a traditional constructed wetland are overcome through physical-chemical-biological multi-path coupling enhanced culture wastewater treatment.

The invention provides a method for recovering nitrogen and phosphorus in wastewater through self-driven bipolar membrane electrodialysis. A system used in the method takes a magnesium negative electrode as a positive electrode and an air electrode as a positive electrode, and a self-driven primary battery is formed through wire connection; and ion exchange membranes with specific sequences are sequentially arranged between the two electrodes to form eight chambers, namely an anode chamber, a nitrogen and phosphorus recovery chamber, a wastewater chamber, a metal ion chamber, an ammonia water chamber, a hydrochloric acid chamber, a buffer chamber and a cathode chamber. During operation, an external power supply is not needed, and ion migration is driven by a self-generated electric field: after Mg < 2 + > and PO4 < 3-> are enriched in the nitrogen and phosphorus recovery chamber and NH4 < + > and Ca < 2 + > migrate to the metal ion chamber, NH4 < + > enters the ammonia water chamber through the monovalent cation exchange membrane, and Ca < 2 + > is separated out and reacts with OH <-> generated by the bipolar membrane to generate Ca (OH) 2 precipitate, so that membrane blockage is effectively prevented, and finally, NH4 < + >, Mg < 2 + > and PO4 < 3-> react to generate high-purity struvite. Zero energy consumption of nitrogen and phosphorus recovery of the wastewater is achieved, no additional chemicals exist, anti-blocking operation is achieved, and both environmental benefits and resource benefits are achieved.

The invention discloses a modified struvite and a preparation method thereof, wherein the surface of the struvite is modified by lignin sulfonate, and at least 85% of the particle size distribution is between 1 and 10 μm. The slurry formed by the modified struvite and water has excellent film-forming properties, can more easily adhere to the surfaces of various substrates and oily leaves to form a dense and uniform fireproof coating, maximizes the contact area with the attached object, and improves the flame retardant effect of the struvite.

The invention belongs to the technical field of solid waste recycling and wastewater treatment, and particularly relates to a method for treating chromium-containing wastewater by adopting organic amine flue gas desulfurization residues. According to the method, organic amine flue gas desulfurization residues are used as a reducing agent, phosphoric acid is used for controlling the pH value of wastewater, hexavalent chromium is reduced into trivalent chromium under the acidic condition, meanwhile, desulfurization ash is converted into a melamine phosphate flame-retardant material, and trivalent chromium is separated from water in a precipitation form under the neutral condition; after the precipitate is roasted, chromium sesquioxide powder with relatively high purity is obtained, residual ammonia nitrogen in the wastewater, the added magnesium salt and residual phosphoric acid in the water form struvite precipitate, so that the ammonia nitrogen in the water is removed, and the struvite can be used as a raw material of a slow-release fertilizer. According to the method, the treatment cost of the vanadium extraction wastewater and the flue gas desulfurization slag is remarkably reduced, valuable elements are fully recycled, and resource utilization of flue gas desulfurization waste in a waste-to-waste mode is achieved.

The invention discloses a low-carbon sludge phosphorus recovery process based on an earthworm compost and struvite precipitation method, which reduces the construction and operation cost through earthworm compost, simplifies the operation technology, reduces the overall carbon emission of the sludge phosphorus recovery process, and can feed earthworms while synchronously recovering nitrogen and phosphorus in sludge. The conversion efficiency of organophosphorus is improved through earthworms and microorganisms, development of the earthworms is promoted through rich organic matter in the sludge, the recovery cost can be compensated after recovery, the synthesized struvite can be used as a soil fertilizer, and high-value utilization of the sludge is achieved.

The utility model belongs to the technical field of industrial wastewater treatment, and particularly relates to a coking wastewater treatment system for industrial continuous production. Comprising a decomposition bin which comprises a moisture evaporation bin, an ammonia decomposition bin, a horizontal transmission belt penetrating through the moisture evaporation bin and the ammonia decomposition bin, a sedimentation tank, a filter connected to an outlet of the sedimentation tank, and a buffer bin connected to an outlet of the filter. The coking wastewater generates struvite in the sedimentation tank, redundant water is filtered out in the filter, and the struvite is stored in the surge bin and then sent to the decomposition bin. The ammonia gas enters the water evaporation bin through the horizontal conveying belt to evaporate redundant water, and then is fed into the ammonia gas decomposition bin to be thermally decomposed to release ammonia gas. The buffer bin can enable intermittent work of the filter not to affect continuous production of the system, the decomposition bin can achieve continuous evaporation dehydration and thermal decomposition processes, the wastewater treatment efficiency is improved, meanwhile, struvite decomposition products are reused in wastewater treatment, cyclic utilization of resources is achieved, and the energy consumption is reduced. The method has good economic benefits and environmental benefits.

The invention relates to a method for treating a mixture M1, said method comprising the following steps: a) a pressurizing step: pressurizing said mixture M1 to obtain a mixture M1p; b) a heating step of heating the mixture M1p to allow a mixture M2 to be obtained; c) a separation step: separating the mixture M2 to obtain an inorganic-rich stream M3 and an inorganic-poor stream M4; d) a hydrothermal gasification step: carrying out hydrothermal gasification on the inorganic-poor material flow M4 to obtain a mixture M5; e) a cooling and separation step of cooling and separating at least a portion of the mixture M5 to separate the gas from a liquid effluent M5'comprising ammonia; f) a possible ammonia enrichment step: subjecting at least a portion of the liquid effluent M5'to an ammonia enrichment treatment to obtain an ammonia-rich stream M5 ''and an ammonia-lean stream M8; g) a mixing step of mixing (i) at least a portion of the stream M3 and (ii) at least a portion of the stream M5'or at least a portion of the stream M5 ", if any, obtained by step f), to obtain a mixture M6; h) a struvite formation step of forming struvite from at least a portion of the mixture M6 in a precipitation reactor; and i) a struvite recovery step: recovering struvite at an outlet of the precipitation reactor. The treatment method further comprises at least one injection step of injecting at least one magnesium salt into the mixture M1 before step a) and / or during step g) and / or during step h) and / or into the mixture M6 between steps g) and h), the mixing step g) may be carried out in the precipitation reactor as desired.

The invention belongs to the technical field of sewage treatment, and discloses a DO-ORP coordinated regulation artificial tidal food web sludge in-situ reduction and phosphorus recovery method. Aiming at the problems of high energy consumption, serious phosphorus resource loss and the like of traditional sludge treatment, a multi-stage food chain consisting of microorganisms, protozoa and metazoan is implanted by constructing an artificial tidal environment with periodic alternation of wetting and drying; according to the method, the metabolic activity of sludge hydrolysis flora and phosphorus-accumulating bacteria is activated by utilizing cooperative regulation and control of DO concentration and ORP, microbial extracellular polymeric substances are triggered to be depolymerized by adopting tidal periodic oscillation, in-situ reduction of sludge biomass is realized by combining a food web cascade predation effect, and phosphorus is synchronously removed by virtue of an anaerobic phosphorus release-aerobic phosphorus uptake coupled struvite crystallization process. The method is suitable for treating the excess sludge of a municipal sewage treatment plant, and the high-purity magnesium ammonium phosphate fertilizer is produced while the dehydration energy consumption is reduced by 40%.

A method of recovery of ammonium phosphate comprises providing a start material (100) comprising struvite into a first aqueous process liquid (101) comprising monoammonium phosphate. The first aqueous process liquid (101) is mixed. Thereby the start material (100) comprising struvite is converted into monoammonium phosphate and / or diammonium phosphate in solution and a residue (103) comprising newberyite as a precipitate. The residue (103) is separated from the first aqueous process liquid (101), thereby giving a second aqueous process liquid (104) comprising monoammonium phosphate and / or diammonium phosphate. At least a part of said second aqueous process liquid (104) or a part of an aqueous process liquid (107, 112) emanating therefrom is returned into the first aqueous process liquid. Phosphoric acid (110) is added. A method for extracting nitrogen from reject water, an arrangement (1) for recovery of monoammonium phosphate and a system for extracting nitrogen from reject water is also disclosed.

The invention belongs to the technical field of sewage treatment, and particularly relates to a lateral flow anaerobic ammonia oxidation effluent deep nitrogen and phosphorus resource recycling method which comprises the following steps: mixing treated anaerobic sludge digestion liquid and untreated anaerobic sludge digestion liquid in an intermediate water tank to form mixed inlet water; adding a magnesium source into the mixed inlet water in the middle water tank to form a middle mixed solution; transferring the intermediate mixed solution into a short-cut denitrification-anaerobic ammonia oxidation coupled struvite reactor, adjusting the pH value of the intermediate mixed solution, and adding a carbon source into the pH-adjusted intermediate mixed solution to form a reaction solution; and carrying out solid-liquid separation on a product obtained after the reaction of the reaction liquid, and discharging the separated liquid or systematically recycling the separated liquid. According to the invention, deep nitrogen removal and phosphorus resource recovery under the condition of low carbon source can be realized, and a new way is provided for subsequent deep treatment of a short-cut nitrification-anaerobic ammonia oxidation process.

The utility model relates to a struvite dephosphorization device for anaerobic effluent, which mainly solves the technical problems of high moisture content, more impurities and the like of products of the existing dephosphorization device. The device comprises a fluidized bed reactor with a cylindrical structure, and the fluidized bed reactor sequentially comprises a collecting area, a reaction area and a settling area from bottom to top. The lower part of the reaction area is provided with a water inlet, a medicament inlet and a reflux inlet which are respectively connected with a water inlet pump, a medicament pump and a reflux pump; a reaction sleeve is arranged at the middle lower part of the reaction area; an aeration head is arranged in the reaction sleeve. And the diameter of the upper barrel of the reaction area is gradually increased and transited to the settling area. A settlement sleeve is also arranged in the settlement area. And the bottom of the sedimentation tank is connected with a reflux pump and a reflux inlet through a pipeline. A gas inlet is formed in the top of the settlement area and connected with an aeration head through a gas pipeline; the gas pipeline is connected with a flowmeter and a gas pump. The bottom of the collecting area is connected with a sludge pump through a pipeline.

The invention discloses a sludge-based flocculation-nutrition multifunctional agent, a preparation method and application of the sludge-based flocculation-nutrition multifunctional agent in muck mud recycling, and belongs to the technical field of solid waste recycling. The invention relates to a preparation method of a sludge-based flocculation-nutrition multifunctional agent. The preparation method comprises the following steps: carrying out hydrothermal carbonization reaction on sludge under the condition of adding NaOH to obtain and separate hydrothermal carbon and nitrogen-rich water phase residues; leaching the hydrothermal carbon in HCl to obtain and separate acid-soaked hydrothermal carbon and a phosphorus-rich leaching solution; mixing the nitrogen-rich water phase residues and the phosphorus-rich leaching liquor, and standing to obtain humic acid precipitate; after sufficient precipitation, NaOH and MgCl2 are added into the mixture, and struvite precipitation is obtained; and putting the acid-soaked hot charcoal, the humic acid precipitate and the struvite precipitate into a polydiene dimethyl ammonium chloride solution, stirring, and separating to obtain the humic acid / struvite composite material. The multifunctional agent can be used for realizing deep resource utilization of the sludge and fully recovering organic matters, nitrogen, phosphorus and the like contained in the sludge.

The invention relates to a method for optimizing struvite production parameters based on response surface method and Minteq combined regulation and control, and belongs to the technical field of parameter optimization. The invention discloses a method for optimizing struvite production parameters based on response surface method and Minteq combined regulation and control. The method has the following advantages: (1) the pH can be regulated and controlled according to the concentration of heavy metals in wastewater, the concentration of bicarbonate maximizes the recovery rate of phosphorus, the occurrence of heavy metals in struvite products is minimized, and the yield of the struvite products is improved; optimal process parameters are provided for safe and healthy application of agricultural soil fertilization; (2) the adopted response surface method has the characteristics of simple operation, high feasibility and accurate prediction; (3) regulation and control can be performed according to the concentration and alkalinity of heavy metals contained in phosphorus-containing wastewater of pig manure wastewater, and high-quality phosphorus recovery of different types of wastewater is realized; and (4) parameter regulation and control can be carried out according to the measured wastewater with phosphorus recovery value, the dosage of sodium hydroxide is saved, and the cost is greatly saved.

The invention relates to the technical field of winery cellar bottom water treatment, in particular to a winery cellar bottom water nitrogen and phosphorus recovery system. A scraping assembly is arranged in the reaction tank and is used for conveying struvite towards one side of the sinking position; wherein a transplanting assembly is further arranged above the reaction tank, two stock bin assemblies are arranged above the transplanting assembly, and a throwing assembly for throwing chemicals in the stock bin assemblies into the reaction tank is further arranged on the transplanting assembly. After cellar bottom water enters the reaction tank, the transplanting assembly can drive the two independent stock bin assemblies; a magnesium source agent and an alkali source agent are synchronously added, and the arranged throwing assembly is combined with the transverse moving function of the transplanting assembly, so that full-coverage and uniform adding of the agents in the reaction tank can be realized, and uniform dispersion of the agents is ensured.

The present invention relates to a fertilizing composition based on renewable phosphate fertilizers by proposing a composition which includes struvite, at least two trace elements, at least one secondary element, and at least one clay.

The invention discloses a device for resource treatment of iron phosphate wastewater through cooperation of a spiral carbon felt and a magnesium metal plate, the device comprises an electrolytic reaction device, the electrolytic reaction device comprises an iron phosphate wastewater container and a spiral device arranged in the iron phosphate wastewater container, and the spiral device comprises a spiral device and a modified carbon felt wound on the spiral device; the modified carbon felt is wound upwards clockwise around the spiral structure of the spiral device from the bottom end of the outer wall of the spiral device, and the modified carbon felt is fixed at equal intervals in the winding direction through a fixator and is wound to the top end of the spiral device; a magnesium metal plate is arranged in an inner hole of the spiral device; the spiral device is provided with a precipitator corresponding to the bottom of the magnesium metal plate; the modified carbon felt is used as the cathode to replace a traditional titanium plate or graphite plate, the waste plastic and the waste carbon felt are made into the spiral device in a spiral shape through the microwave-assisted cracking technology, the modified carbon felt and the spiral device form the spiral device, the design cost is further reduced, struvite is efficiently recycled, and the recycling cost is reduced.

The invention relates to the technical field of sewage treatment, and discloses an aeration fluidization struvite crystallization granulation device which comprises a bottom plate and a rotating rod, the rotating rod is rotationally arranged in the middle of the upper surface of the bottom plate, the upper end of the rotating rod is fixedly sleeved with a rotating disc, and a first motor is fixedly arranged on the lower surface of the bottom plate; and the output end of the first motor is fixedly connected with one end of a rotating rod, machining cylinders are fixedly connected to the two sides of the lower portion of the rotating disc through connecting rods, and a sewage inlet is formed in one side of the upper end of each machining cylinder. According to the aeration fluidization struvite crystallization granulation device, the design of double processing barrels is adopted, when the processing barrel on one side is subjected to material changing and cleaning, the processing barrel on the other side can be kept in a working state, the waste time of material changing and cleaning can be greatly shortened, then the processing efficiency can be improved, the inner walls of the processing barrels can be automatically cleaned, and the labor intensity of workers is reduced. Materials can be effectively prevented from hardening on the inner wall of the barrel, and manpower can be greatly saved.

A sustainable control release fertilizer and a producing method thereof are developed. The sustainable control release fertilizer comprises a natural char / struvite composite with different ratio of the natural char to struvite (0:100, 25:75, 50:50, 75:25). The natural char / struvite composites represent a phosphorus pentoxid content in a range of 16 wt% to 25 wt% which is more than a common phosphate fertilizer. Furthermore, a mole ratio of Mg2+:NH4+:PO4 3- in the sustainable control release fertilizer is 2:1:1. The sustainable control release fertilizer can enhance phosphorus uptake of at least one plant at early stage of growth due to its composition as well as the developed producing method of sustainable control release fertilizer is based on recovery of phosphorus from wastewater that has the good economic and environmental effects.

A method for decomposing struvite comprises dissolving of a feed material comprising struvite in a mineral acid. Thereby a solution having an acid pH is formed. Magnesium is removed from the solution. The removing of magnesium comprises increasing a pH of the solution to a pH in the range of 4.5 to 6, precipitating magnesium compounds that do not comprise ammonium, and separating the precipitated magnesium compounds from the solution. Thereby, the solution, after the removing of magnesium, comprises an ammonium salt of the mineral acid. An arrangement for performing such a method is also disclosed. Also, a method and arrangement for recovering at least nitrogen from waste material, based on the decomposing of struvite are disclosed.

A fertilizer is provided that promotes plant growth with limited phosphate run-off. The fertilizer has reduced run-off even when compared to a phosphorus normalized application of struvite. The fertilizer is based on suspended colloidal particles in aqueous solution. The colloidal particles have a size distribution in which 95 percent of the colloidal particles are less than 60 microns and have an atomic number ratio of magnesium:nitrogen:phosphorus of 1:0-3:0.5-3. The colloidal particles are heterogeneous and include domains of only struvite, or of struvite in combination with domains of pyrophosphate species, poly phosphate species, or combinations thereof. The fertilizer composition is formulated to include additional components while still retaining colloidal suspension storage stability. The colloidal particles are produced from concentrated solutions that facilitate industrial scale production. The colloidal particles promote bioavailability through root acid phosphatases activation of insoluble phosphorus species. The colloid domain size facilitates access and soil intercalation over run-off mechanisms.

The invention discloses a preparation method of dolomite modified municipal sludge biochar and application of the dolomite modified municipal sludge biochar in pig farm biogas slurry nitrogen and phosphorus recovery. The preparation method comprises the following steps: firstly, drying and grinding dolomite and municipal sludge; mixing the two according to a specific proportion, putting the mixture into a tubular furnace filled with nitrogen flow, and regulating and controlling pyrolysis temperature and pyrolysis time to release active ingredients such as magnesium oxide, so as to prepare the biochar material. Then, the prepared biochar material is added into pig farm biogas slurry simulated wastewater, and the adsorption performance and the optimal adsorption condition of the material are explored. The setting of experimental conditions relates to the adjustment of adsorption time and initial reaction pH. According to the dolomite modified sludge biochar prepared by the method, ammonia nitrogen and phosphorus can be efficiently recovered from biogas slurry, struvite rich in nitrogen and phosphorus is generated, and the dolomite modified sludge biochar becomes a biochar-based fertilizer.

This utility model relates to the field of wastewater treatment and resource recovery technology, specifically disclosing an integrated device for anaerobic fermentation of sludge to produce biogas and recover phosphorus, including: an anaerobic fermentation unit, a phosphorus recovery unit, a sludge treatment unit, a biogas recovery unit, a dosing unit, and a PLC control device. In this integrated device, after the phosphorus-rich supernatant released from the anaerobic fermentation unit enters the sedimentation tank, the PLC control device adjusts the pH to 8.5-9.0 according to data from a pH monitor, using a sodium hydroxide dosing machine, while simultaneously adding magnesium chloride via a magnesium chloride dosing machine. 2+ , prompting PO4 3‑ NH4 + With Mg 2+ The reaction produces struvite, which is then accelerated by adding PAM through a PAM dosing machine. Finally, the struvite is collected and dried through an inclined tube, realizing the targeted recovery and resource utilization of phosphorus in sludge. This avoids eutrophication of water bodies caused by phosphorus discharge with sludge and significantly improves the utilization rate of phosphorus resources.

The invention relates to the technical field of sewage treatment, in particular to a method for recovering phosphorus resources in excess sludge concentrated clear liquid in situ, which comprises the following steps: additionally arranging a reaction sedimentation tank at the front end of a sewage treatment biological system, introducing excess sludge concentrated clear liquid and part of sewage, and monitoring the flow of the sludge clear liquid, the phosphorus concentration and the ammonia nitrogen concentration in the sewage in real time. The sewage diversion flow and the magnesium liquid adding amount are automatically adjusted, the alkaline environment is regulated and controlled to promote struvite to crystallize and precipitate, and efficient phosphorus recovery is achieved. According to the method, automatic control and chemical precipitation principles are combined, only the existing process needs to be locally modified, the operation cost is low, the occupied area is small, the phosphorus recovery rate exceeds 99%, the generated struvite can be directly used as a phosphate fertilizer, the remarkable economic value is achieved, and meanwhile stable operation of a follow-up biological treatment unit is guaranteed.

The invention relates to the technical field of wastewater treatment, and discloses a fluidized bed crystallization device for recovering high-purity large-particle-size particle struvite from biogas slurry, the fluidized bed crystallization device comprises a support frame, the inner wall of the support frame is provided with a crystallization mechanism, the crystallization mechanism is internally provided with a cleaning mechanism, the bottom of the cleaning mechanism is provided with a stirring mechanism, and the stirring mechanism is arranged on the inner wall of the support frame. An aeration mechanism is arranged on the outer side of the supporting frame, one end of the aeration mechanism is arranged at the bottom of the stirring mechanism, a dismounting mechanism is arranged at the bottom of the crystallization mechanism, the aeration mechanism comprises an air compressor, the air compressor is installed on the outer side of the supporting frame, and the output end of the air compressor is fixedly connected with a flow dividing pipeline. The motor drives the rotating disc to drive the connecting rod to rotate and sweep, the limiting sliding block slides in the guide sliding groove to prevent deviation, the rotating disc is further connected with the rotating rod to drive the stirring blades to stir and mix materials, meanwhile, the fixing sleeve is driven to rotate, the two-way aeration pipe rotates synchronously, and aeration uniformity and reaction efficiency are improved.

The invention belongs to the technical field of environment-friendly fire extinguishing materials, and particularly relates to fire extinguishing powder based on seed crystal induced struvite and a preparation method of the fire extinguishing powder. The method comprises the following steps: by taking nitrogen and phosphorus-rich supernate in a sewage treatment plant as a raw material, firstly removing heavy metal ions in sewage through a cation selective permeable membrane, then adjusting the pH value of the supernate and the ratio of nitrogen to phosphorus, introducing seed crystal to induce struvite (MAP) to crystallize and precipitate, and filtering and drying to obtain seed crystal induced synthesized MAP particles; a horizontal planetary ball mill is further adopted, MAP and a modifier are evenly mixed and ground, and the MAP fire extinguishing powder with the good fire extinguishing performance is prepared. The layered double hydroxide (LDH) is creatively adopted as a seed crystal inducer, the pyrolysis starting temperature of the layered double hydroxide (LDH) can be remarkably increased, meanwhile, the thermal decomposition dynamic process is optimized, and therefore the thermal stability and the fire extinguishing efficiency of the layered double hydroxide (LDH) serving as the dry powder fire extinguishing agent are greatly improved.