52 results about "Struvite Crystals" patented technology

An apparatus and method for removing phosphorus from a wastewater effluent stream from a hog waste lagoon. The wastewater effluent is introduced to the bottom of an inverted cone-shaped continuous crystallizer including a fluidized bed of struvite therein. An effective amount of ammonia is introduced to the wastewater effluent at the bottom of the crystallizer to elevate the pH of wastewater effluent a predetermined amount. An effective amount of magnesium is also introduced to the wastewater effluent at the bottom of the crystallizer. The composition adjusted wastewater effluent is then continuously passed upwardly through the fluidized bed of struvite to reduce the total phosphorus content of the wastewater effluent a predetermined amount of up to about 80% or more. The treated wastewater effluent stream is removed from the top of the crystallizer, and struvite crystals that grow large enough to sink from the bottom of the crystallizer are periodically removed from a collection chamber therebeneath.

The invention relates to a device and a process for preparing struvite crystals from nitrogen and phosphorus in sewage. The device comprises a reactor (5), a pH (potential of Hydrogen) controller (25), a pH regulating pump (24), an alkali liquor tank (23), a nitrogen and phosphorus containing waste water tank (22) and a secondary sedimentation tank (19), wherein the reactor (5) is composed of a reactor feed pipe (9), a reactor crystal collecting pipe (8), a reactor growth tube (3) and a reactor sediment tube (2) from bottom to top. The process comprises the steps of pumping nitrogen and phosphorus containing wastewater into the reactor (5) and pumping a magnesium chloride solution into the reactor (5) to ensure that the molar ratio of NH3-N to PO43-P to Mg <2+> in the reactor (5) is (1:1:1)-(1:1:1.3); controlling the reflux ratio between 14 and 28 and the pH equal to 6.4-9.2; and forming the struvite crystals in the reactor (5) by using the nitrogen, phosphorus and magnesium containing solution. The device disclosed by the invention has the advantages of simple structure and small floor space, is simple and easy to operate and difficult to scale, can be widely applied to preparation of the struvite crystals from the nitrogen and phosphorus containing wastewater such as coking wastewater, pig manure wastewater or sludge fermentation liquor, and is capable of realizing the resource recycling of nitrogen and phosphorus.

The present invention provides a method for removing phosphorus and nitrogen contained in sewage or wastewater using iron ore wastewater. According to the method of the present invention, in which the phosphorus and nitrogen contained in sewage or wastewater are crystallized in the form of struvite using iron ore wastewater containing a large amount of Mg²⁺ produced in a process of upgrading low-grade iron ore and removed, it is possible to reduce the cost of Mg²⁺ and the cost of iron ore wastewater treatment, thereby earning economic profits. Moreover, it is possible to prevent water pollution by the removal of the phosphorus and nitrogen contained in sewage or wastewater. Furthermore, it is possible to use struvite crystals obtained as a by-product as a time-release compound fertilizer so as to reduce the amount of fertilizer used and the number of fertilizations, thereby reducing soil contamination.

The invention discloses a method of recovering phosphorous from municipal sludge by hydrothermal carbonization. The method comprises the following steps: (1) carrying out hydrothermal carbonization onmunicipal sludge to obtain a carbonized product; (2) carrying out solid liquid separation on the carbonized product obtained in the step (1) to obtain charcoal and a liquid phase product, separately;(3) extracting phosphorous from charcoal obtained in the step (2) by an acid leaching method and filtering the mixture to obtain a filtrate; and (4) adding magnesium salt and ammonium salt into the filtrate obtained in the step (3), adjusting the pH to form struvite crystals and recovering the same. By converting organic phosphorous in sludge through the hydrothermal carbonization reaction into inorganic phosphorus and concentrating the inorganic phosphorus into charcoal and carrying out acid extraction on the phosphorous enriched charcoal and crystallizing struvite, simple and efficient municipal sludge treatment and phosphorous recovery with a low cost are achieved.

The invention relates to a recycling process for synchronously strengthening anaerobic acid production and phosphorus recovery of sludge. The process comprises the following steps: (1) pretreating residual sludge by adopting a thermal activation persulfate pre-oxidation process; (2) cooling the pretreated sludge obtained in the step (1) to room temperature, adjusting the pH value, and carrying out anaerobic fermentation to produce acid; (3) carrying out solid-liquid separation on the anaerobic fermentation sludge obtained in the step (2); and (4) adding magnesium salt into the filtrate obtained in the step (3), adjusting the pH value, conducting filtering to obtain struvite crystal precipitate, carrying out phosphorus recovery, and backflowing the residual filtrate as a carbon source to a sewage treatment plant. Compared with the prior art, the method provided by the invention overcomes the defect that various existing technologies cannot simultaneously meet the requirements of high-efficiency release and high-added-value recovery of phosphorus in the anaerobic recycling process of the sludge; the peroxysulphate pre-oxidation can strengthen the anaerobic phosphorus release of the sludge; and the sludge can be cracked, and anaerobic fermentation and acid production of the sludge are enhanced.

The invention discloses a synchronous recovery treatment method for nitrogen and phosphorus in high-solid-content anaerobic digested sludge, which comprises the following steps of: (1) carrying out acid dissolution on anaerobic digested sludge to obtain an acid-soluble product; (2) carrying out solid-liquid separation on the acid-soluble product obtained in the step (1) to obtain a mud cake and press filtrate; (3) adding cation exchange resin into the press filtrate obtained in the step (2), removing metal impurities, and filtering to obtain filtrate; and (4) adding magnesium salt into the filtrate obtained in the step (3), and adjusting the pH value to form struvite precipitate for recovery. According to the method, phosphorus in the anaerobic digestion sludge is released into the biogasslurry through acid dissolution, then impurities are removed, and finally struvite crystals are formed by utilizing wastes, so that efficient recovery of nitrogen and phosphorus in the anaerobic digestion sludge is synchronously realized.

The invention belongs to the field of microbial electrochemistry, and discloses a method for in-situ recovery of high-purity struvite through a microbial electrolytic cell. The method comprises the steps that at least one of phosphorus-containing wastewater and phosphorus-containing sludge is added into the microbial electrolytic cell after microbial acclimation, an external voltage is applied tocarry out a microbial electrolysis reaction for a period of time, and then struvite sediment can be separated out, wherein the external voltage is smaller than the electrolytic voltage of water. According to the method, a microbial electrolytic cell (MEC) technology is utilized, and micro-voltage less than that of electrolytic water is adopted so that the problems that the time for obtaining the struvite through ectopic crystallization is long, the purity is low, particles are small and the sedimentation and separation performance is poor can be effectively solved, and the electric energy consumption is greatly reduced. Moreover, the method is based on an in-situ reaction, on the premise that stirring is not needed, the nucleation rate of struvite crystals is increased, the growth rate ofthe struvite crystals is increased, the limit of the growth of the struvite crystals is broken through, the particle size of the struvite is increased, the purity of the struvite is improved, and in-situ crystallization recovery of the high-purity struvite is achieved.

The invention discloses a device and method for electrochemical precipitation recovery of nitrogen and phosphorus in surplus sludge. The device comprises surplus sludge tank, surplus sludge anaerobic fermentation tank, fermentation liquid sedimentation tank, electrochemical reaction tank and water storage tank. The electrochemical reaction tank has built-in anode magnesium rods and cathode carbon rods to realize the recovery of nitrogen and phosphorus in the remaining sludge by forming struvite. The method of using this device to recover nitrogen and phosphorus in excess sludge is as follows: introduce the anaerobic fermentation liquid of excess sludge into the electrochemical reaction tank to provide ammonia nitrogen and phosphorus, and under the action of a direct current electric field, electron transfer occurs between the anode magnesium rod and the cathode carbon rod to provide Mg2+ and OH‑, free-settled struvite crystals in the conical precipitation zone for recovery, and the supernatant after nitrogen and phosphorus removal overflowed into the water storage tank. The device of the invention can realize synchronous recovery of nitrogen and phosphorus in excess sludge without additional addition of magnesium ion reagents, and the recovery product has considerable economical efficiency.

The invention relates to a low-pressure liquid flowing control magnetic valve (cycle device), relative system and method, which uses tube to discharge the liquid in bladder, wherein it can connect special discharge tube, to be one flow balance system; the cycle device can connect the catheter, to discharge bladder. Said valve is switched fully automatically, to discharge the urine, while it can respond the pressure of normal animal, or be operated by hand. The invention can be checked by U.S.F.D.A (America food and drug manage committee).

The invention relates to a method for quickly and efficiently synchronously recovering sources to separate urine and phosphorus in the anaerobic supernatant of septic tanks, which is characterized in that the method is carried out according to the following steps: 1. Transforming the sewage pipeline of a traditional flushing urinal ; 2. Use the urine source separation controller to realize the separation and collection of urine and flushing water; 3. Perform anaerobic fermentation on the septic tank sewage, and then filter the supernatant through double-layer grids; 4. Distill the supernatant After the liquid and stored urine are filtered through a fine sand column, they are mixed according to a certain ratio, so that the pH of the mixed solution is in the range of 8.4 to 8.6, and the off-white precipitate rich in struvite is recovered; 5. Use infrared diffraction spectroscopy and chemical methods to identify the Struvite purity. By strictly controlling parameters such as pH value and stirring speed of wastewater, the invention can not only recover phosphorus in urine and septic tank wastewater synchronously, reduce environmental pollution, reduce wastewater treatment cost, but also obtain high-purity struvite crystals. The invention has the advantages of low cost, simple process, high efficiency and rapidity.

The invention provides a multistage fermentation device containing a fermentation liquor reflux and denitrification system, and belongs to the technical field of biomass resource recovery. The device comprises a feeding system, a multistage fermentation system, a biogas residue treatment system, a solid-liquid separation system, a fermentation liquor denitrification system, a biogas liquid reflux system, biogas liquid and biogas residue pipelines, pumps, valves and flowmeters. The feeding system comprises a biomass pretreatment device and a mixed feeding device; the multistage fermentation system is formed by multiple fermentation tanks which are connected in series or in parallel; the fermentation liquor denitrification system is composed of a reactor, an aeration device with replaceable steel mesh, a stirring device, a water quality regulating device and a struvite recovery tank; the biogas liquid reflux system is composed of the biogas liquid pipeline, the pump, the valve and the flowmeter. The multistage fermentation device containing the fermentation liquor reflux and denitrification system has the advantages of being capable of cycling struvite crystals, effectively reducing ammonia nitrogen concentration in reflux fermentation liquid, relieving the fermentation system ammonia inhibition effect and improving the fermentation system performance and capable of being applied to anaerobic fermentation of biomass.

The invention discloses a regulation and control method for efficiently recovering phosphorus in livestock and poultry feces. The regulation and control method comprises the steps of introducing the livestock and poultry feces into a microwave induced oxidation control reactive tank, adding an oxidant solution and oxygen, and performing pulsed microwave irradiation by using a microwave regulation and control device; introducing supernatant fluid of the treated livestock and poultry feces into a microwave crystallization process control reactive tank, adding a magnesia mixture solution and a pH value regulating agent, performing mechanical stirring on the mixed solution, and performing pulsed microwave irradiation by using the microwave regulation and control device; introducing the supernatant fluid after reaction into a sedimentation tank, and overflowing water by adopting a decanter; and performing intermittent sludge discharge control on struvite crystal mud, and recovering the crystal mud by adopting a bag filter. The method disclosed by the invention can improve the recovery efficiency of phosphorus in the livestock and poultry feces, and the phosphorus recovery rate is more than 99%; the method disclosed by the invention can be used for efficiently converting organic phosphorus in the livestock and poultry feces into inorganic phosphorus, the conversion rate of the organic phosphorus is more than 99%, and the conversion time is less than 60 minutes; the method disclosed by the invention can be used for regulating and controlling the width and position of a metastable region of struvite crystals to realize efficient crystallization and granulation of struvite.

The invention provides an integrated treatment method of heavy metal passivation and nutrient nitrogen and phosphorus recovery for domestic animal sewage. Heavy metal element passivation and activation and release of nutrients nitrogen and phosphorus are achieved by adopting an integration technology of ionizing irradiation/iron-carbon micro-electrolysis fluidized bed, and efficient recovery of the nutrients nitrogen and phosphorus is achieved by adopting an integration technology of disc tube reverse osmosis/struvite crystal/hydrated molten iron oxide-carrying hot carbon. The copper-zinc-lead-chromium passivation rate is greater than 90%, the nitrogen element recovery rate is greater than 90% and the phosphorus element recovery rate is greater than 95%.

The invention discloses a device and a method for inducing generation of struvite by virtue of microorganisms. The device comprises a reaction unit, a precipitation unit and a water circulating unit, wherein the reaction unit comprises a fluidized bed reactor, packing in the fluidized bed reactor, a pH meter and a temperature regulator; a precipitator in the precipitation unit communicates with the fluidized bed reactor by virtue of a conduit; three outlets are formed in the precipitator; and the water circulating unit and the fluidized bed reactor can achieve reflux with the precipitation unit. According to the device provided by the invention, the packing in the fluidized bed reactor can serve as an attachment carrier of the microorganisms; and by virtue of the water circulating unit, a water flow can rise more uniformly, which is conducive to the fluidized growth of struvite crystals, and generated struvite particles are uniform and dense. The size of the device provided by the invention is greatly diminished, so that engineering investment and occupied land area are significantly reduced; and the device is low in energy consumption, high in efficiency and strong in operating flexibility, and the device has an important application value.

The invention discloses a circulating fluidized crystallization control reaction device for wastewater phosphorus synergy crystallization and a dynamic monitoring and regulating method thereof. The device is characterized in that a crystallization regulating device is connected with a filter through a mud discharge pipe, and the filter is connected with a saturated liquid buffer tank through a liquid pumping pipe; the saturated liquid buffer tank is respectively connected with a dynamic monitoring tank and the crystallization regulating device, and the dynamic monitoring tank is connected with the crystallization regulating device. The method comprises the following steps: regulating the concentration of wastewater phosphorus and the concentration of magnesium salt in the dynamic monitoring tank and a pH value; dynamically monitoring and regulating the oversaturated state of struvite crystal-inducing liquid in a metastable state, and conducting fluidized state reaction with seed crystal added into the saturated liquid buffer tank in the crystallization regulating device; separating crystal from mud through the filter, and discharging crystal slag to the outside; after discharging saturated liquid into the saturated liquid buffer tank and layering, discharging clarified saturated liquid into the dynamic monitoring tank, and discharging precipitated fine crystal into the crystallization regulating device. According to the circulating fluidized crystallization control reaction device for wastewater phosphorus synergy crystallization and the dynamic monitoring and regulating method thereof, the crystallization efficiency of struvite can be increased, and the crystallization efficiency of wastewater phosphorus is larger than 99 percent.

The invention discloses a dephosphorization method of chemical wastewater generated in a process of producing hydrogen peroxide through an anthraquinone method. The dephosphorization method comprises the following steps: adding sodium hydroxide into the chemical wastewater generated in the process of producing hydrogen peroxide through the anthraquinone method and carrying out a hydrolysis reaction; converting organic phosphorus in the chemical wastewater into inorganic PO4<3->; adding ammonia salt and magnesium salt to be subjected to a struvite crystal precipitation reaction with the inorganic PO4<3->; and separating out sediment to obtain dephosphorized wastewater. The method disclosed by the invention is simple in technological process, small in secondary pollution and low in cost; special equipment is not needed, and the investment and operation cost is low, and the dephosphorization method is easy to popularize and apply; and the difficulties that the content of total phosphorus and organic phosphorus in the wastewater generated in the process of producing hydrogen peroxide is high, the subsequent load of a sewage treatment plant of a biochemical system is great and the total phosphorus of output water difficultly reaches standards are effectively overcome.

The invention relates to a human and animal excreta treatment system, which comprises an excreta collection system provided with an excreta collection unit and a urine collection unit; an excrement treatment system provided with an excrement dry distillation treatment unit or an excrement hydrothermal synthesis treatment unit, and used for treating the excrement collected by the excrement collection unit to prepare biochar; and an urine treatment system provided with a urine pretreatment unit, an artificial wetland unit and a wetland plant dry distillation treatment unit, wherein the urine pretreatment unit is used for treating urine mixed liquid collected by the urine collection unit to obtain struvite crystals, the artificial wetland unit is used for purifying redundant tail water treated by the urine pretreatment unit and treating the purified tail water, and the wetland plant dry distillation unit is used for preparing charcoal from the wetland plants after tail water treatment and treating human and animal excreta of excrement and urine at the same time. The invention further relates to a human excrement treatment method and a livestock excrement treatment method.

The invention discloses a method for recovering phosphorus from sludge rich in chemical phosphorus precipitates by using high-protein biomass waste, which comprises the steps of putting the sludge rich in chemical phosphorus precipitates into an anaerobic fermentation tank, adding a certain amount of high-protein biomass by-products in proportion according to the total chemical oxygen demand of the sludge, and carrying out closed fermentation for 4-7 days, thereby not only being capable of effectively improving the phosphorus release rate of the sludge rich in chemical phosphorus precipitates, but also being capable of generating volatile short-chain fatty acid and ammonia nitrogen with high concentration. After dehydration treatment, phosphorus and part of ammonia nitrogen can be recovered in the form of high-purity struvite crystals only by adding a proper amount of magnesium salt into the sludge dehydration liquid and adjusting the pH value to 7.5-9.0, and meanwhile, high-concentration volatile short-chain fatty acid in the dehydration liquid can be used as an economic carbon source for improving the nutritive salt removal efficiency of a sewage treatment plant. According to the method provided by the invention, the two solid wastes are subjected to resource utilization at the same time, and carbon, nitrogen and phosphorus resources are recovered. In addition, the dosage of chemical agents can be reduced, and the treatment cost is saved.

The method comprises the following steps: S1, conveying ammonia-nitrogen wastewater to be treated into a magnetizing reactor, adding a phosphorus source, controlling the nitrogen-phosphorus ratio, adding a magnesium source under an alkaline condition pH value to generate a part of precipitate, and dropwise adding the magnesium source under a neutral slightly alkaline pH value until the reaction is complete; S2, adding magnetic seeds, uniformly stirring and mixing, conveying into an electric flocculation device, and carrying out electric flocculation reaction by using pulse current; S3, conveying the wastewater treated in the step S2 into a magnetic separation device, discharging a liquid phase part after magnetic separation, and collecting a solid phase part; and S4, conveying the collected solid-phase part into a magnetic recovery device, recovering the magnetic seeds, and taking the rest part as the struvite crystal precipitate. According to the scheme of the embodiment of the invention, by combining electric flocculation and magnetic flocculation, struvite crystals can keep an intact crystal form structure, and the capacity of slowly releasing nitrogen and phosphorus is high.

The invention discloses a method for recycling phosphorus resources in municipal excess sludge. The method comprises the following steps: (1) feeding part of sludge into a pretreatment reaction tank for pretreatment; the amount of the exported sludge is 30%-60%; adding an oxidizing agent for oxidation reaction; (2) reducing the water content of the residual sludge to 96-99% in a fermentation tank in a gravity concentration manner, and adjusting the pH value of the residual sludge to 9-12; (3) mixing the pretreated sludge and residual sludge with the moisture content of 96-99% according to the volume ratio of (2: 1)-(4: 1), and performing anaerobic fermentation for 30-56 hours; (4) adding rhamnolipid, wherein the addition amount of rhamnolipid is 0.025-0.1 g/g of TSS; and (5) phosphorus absorption: taking the fermentation supernatant, adjusting the pH value to 9-11, adding magnesium salt into a fluidized bed according to the molar ratio of phosphate to 1.5: 1-2.0: 1, producing struvite crystals, and separating under the action of gravity to realize the recovery of phosphorus and nitrogen in the supernatant. According to the method for recycling the phosphorus resource in the municipal excess sludge, secondary pollution is avoided, and the phosphorus resource in the sludge is recycled to the maximum extent.