A sewage treatment device for graded release of carbon source and simultaneous recovery of phosphorus

Abstract

The present application relates to sewage treatment technical field, specifically to a kind of sewage treatment equipment of hierarchical release carbon source and simultaneous phosphorus recovery, including water inlet unit, for receiving carbon-containing organic sludge or sewage;Carbon source conversion unit, in communication with water inlet unit;Phosphorus migration control unit, in communication with carbon source conversion unit, adopt multi-stage reaction tank structure and dynamic sludge backflow channel;Phosphorus separation and recovery unit, in communication with phosphorus migration control unit;Water outlet unit, in communication with phosphorus separation and recovery unit, for output standard water;Automatic control system, connected with above-mentioned each unit, for linkage adjustment the operating parameter of each unit.Compared with prior art, the present application is provided with carbon source conversion unit, can effectively inhibit methanation side reaction, improve carbon source conversion efficiency, simultaneously by flexible adjustment operating parameter adaptation different water quality characteristics, provide stable and reliable carbon source supply for subsequent phosphorus recovery and denitrification and phosphorus removal process, realize the overall optimization of sewage treatment process.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a wastewater treatment device that provides staged release of carbon sources and simultaneous phosphorus recovery. Background Technology

[0002] With the acceleration of urbanization and the increase in industrial emissions, the concentrations of pollutants such as organic matter, nitrogen, and phosphorus in urban and industrial wastewater are constantly rising. Traditional wastewater treatment technologies face problems such as low efficiency, poor resource utilization, and unstable effluent quality. This not only affects the compliance of wastewater discharge with standards but also increases subsequent treatment and management costs. In recent years, with the promotion of the circular economy concept and sustainable development strategy, how to achieve efficient utilization of carbon sources, simultaneous removal of nitrogen and phosphorus, and recovery of phosphorus resources in wastewater treatment has become an important research direction and engineering practice hotspot in the field of environmental engineering.

[0003] However, in existing technologies, traditional wastewater treatment systems typically use external carbon sources directly or rely on ungraded sludge organic matter. These methods cannot achieve graded release and precise control of carbon sources, easily leading to insufficient or wasted carbon resources. Simultaneously, the downstream denitrification or polyphosphate-accumulating organism (PAO) treatment's demand for carbon sources is difficult to precisely match, resulting in low reaction efficiency and significant methanation side reactions, causing some organic matter to be ineffectively lost, thus increasing system operating costs and energy consumption. Regarding phosphorus treatment, traditional equipment often uses single aerobic / anoxic tanks or chemical precipitation to remove phosphorus, making it difficult to achieve simultaneous control of phosphorus release and uptake by PAOs. This makes phosphorus recovery rates highly susceptible to load fluctuations; low concentrations of phosphorus in the liquid phase are easily discharged directly with the effluent or lost during sedimentation, leading to phosphorus resource waste and potential environmental pollution. Furthermore, traditional systems have poor adaptability to water quality changes and cannot maintain stable operation under fluctuating water quality or high load conditions, further limiting the overall efficiency and resource utilization potential of wastewater treatment systems. Therefore, this application discloses a wastewater treatment device for graded carbon source release and simultaneous phosphorus recovery. Summary of the Invention

[0004] In view of this, the purpose of this invention is to propose a wastewater treatment device that releases carbon sources in stages and recovers phosphorus simultaneously, in order to solve the problems of uncontrollable carbon source release, low downstream reaction efficiency, significant methanation loss, difficulty in synchronously controlling phosphorus removal and unstable recovery rate, poor adaptability of the system to changes in water quality, resulting in resource waste and high operating costs in traditional wastewater treatment systems.

[0005] Based on the above objectives, the present invention provides a wastewater treatment device for staged release of carbon source and simultaneous phosphorus recovery, including an influent unit for receiving carbon-containing organic sludge and wastewater.

[0006] A carbon source conversion unit, connected to the water inlet unit, is used to decompose carbon-containing organic matter into soluble small molecule carbon sources.

[0007] The phosphorus migration control unit, connected to the carbon source conversion unit, adopts a multi-stage reaction tank structure and a dynamic sludge return channel to achieve phosphorus enrichment and controllable release.

[0008] The phosphorus separation and recovery unit, connected to the phosphorus migration control unit, includes a pH adjustment zone, a precipitation reaction zone, and a solid-liquid separation zone, and is used to achieve phosphorus crystallization precipitation and efficient recovery.

[0009] The effluent unit is connected to the phosphorus separation and recovery unit and is used to output qualified water;

[0010] An automated control system, connected to the aforementioned units, is used to adjust the operating parameters of each unit in a coordinated manner to achieve graded release of carbon sources and simultaneous recovery of phosphorus.

[0011] Preferably, the carbon source conversion unit includes a series multi-stage reaction zone, each of which is equipped with an independent stirring device and a temperature control system to achieve the staged release of the carbon source;

[0012] The multi-stage reaction zone is functionally divided as follows:

[0013] Primary hydrolysis zone: temperature 35±1℃, HRT=6-8h, releases acetic acid and propionic acid;

[0014] Secondary acidification zone: temperature 45±1℃, HRT=10-12h, release butyric acid and valeric acid;

[0015] Level III stability zone: temperature 25±1℃, HRT=4-6h, carbon source COD concentration stabilized at 8000-10000mg / L.

[0016] Preferably, the acid production reaction module of the carbon source conversion unit is configured with:

[0017] Acidification bacterial inoculation area: equipped with immobilized compound bacterial agent containing Clostridium and Bacillus;

[0018] Acidity monitoring device: used to detect VFA composition in real time and feed it back to the control system. When the butyric acid content is greater than 40%, the HRT of the secondary acidification zone is automatically extended to 14 hours.

[0019] Preferably, the multi-stage reaction tank structure includes an anaerobic tank, an anoxic tank, and an aerobic tank arranged in sequence, wherein a PAOs biofilm carrier is provided at the end of the aerobic tank; the dynamic sludge return channel includes a side-flow phosphorus release tank, which releases 10% of the returned sludge into the anaerobic tank under anaerobic conditions for 2 hours and then returns it to the anaerobic tank, with a phosphorus release rate ≥80%.

[0020] Preferably, the dynamic sludge return channel adjusts the return ratio R based on the real-time value of the oxidation-reduction potential sensor. When ORP ≥ -150 mV, the return ratio R is 80%; when ORP < -250 mV, the return ratio R is 150%.

[0021] Preferably, the pH adjustment zone uses CO2 aeration and NaOH fine-tuning to maintain pH=8.5-9.0, and MgCl2 / Ca(OH)2 is added to generate struvite or hydroxyapatite to promote the formation and precipitation of struvite or hydroxyapatite.

[0022] The precipitation reaction zone is equipped with an inclined plate precipitator and a micro vortex flocculant to accelerate particle aggregation and sedimentation.

[0023] The solid-liquid separation zone uses a ceramic membrane filter with a pore size of 0.1 μm to remove residual suspended solids and colloidal particles.

[0024] Preferably, the automated control system implements a carbon-phosphorus synergistic strategy, which includes the following steps:

[0025] S1: Based on historical C / N / P data of the influent, predict the carbon source demand and dynamically adjust the HRT of the multi-stage reaction zone to match the carbon source demand of the influent;

[0026] S2: Based on the TP concentration at the end of the aerobic tank, control the Mg / Ca molar ratio for struvite / hydroxyapatite crystallization to maintain crystallization efficiency;

[0027] S3: When the TP of the effluent from the solid-liquid separation zone is greater than 0.5 mg / L, activate the emergency carbon source storage tank to add sodium acetate to ensure that the effluent meets the standards stably.

[0028] Preferably, the automated control system further includes an online monitoring module, which is equipped with a pH sensor, an ORP sensor, an online COD analyzer, and a total phosphorus monitor to realize real-time monitoring and feedback adjustment of the operating status of the multi-stage reaction zone and the phosphorus separation and recovery unit.

[0029] Preferably, the carbon source conversion unit, phosphorus migration control unit, and phosphorus separation and recovery unit are coupled into an integrated device through pipelines, and each unit is provided with a bypass pipeline and a switching valve. The bypass pipeline is used to isolate the faulty unit during equipment maintenance so as to flexibly switch between continuous flow mode and batch mode.

[0030] Preferably, the automated control system is further connected to an external SCADA / host computer communication module for remote monitoring and data storage.

[0031] The beneficial effects of this invention are:

[0032] 1. This wastewater treatment equipment, which features staged carbon source release and simultaneous phosphorus recovery, incorporates a carbon source conversion unit. Through a series of multi-stage reaction zones and an intelligent control system, it achieves efficient conversion and precise release of carbon sources. The primary hydrolysis zone decomposes macromolecular organic matter into readily available carbon sources such as acetic acid and propionic acid under mild conditions. The secondary acidification zone enhances reaction conditions to promote the generation of medium-chain fatty acids such as butyric acid and valeric acid. The tertiary stabilization zone ensures stable output of carbon source components. Each reaction zone is equipped with independent stirring and temperature control devices. Combined with immobilized composite bacterial agents and an online monitoring system, precise control of reaction conditions is achieved. The acidity monitoring device analyzes VFA composition in real time and dynamically adjusts the hydraulic retention time to ensure precise matching of carbon source components with downstream treatment requirements. This system effectively suppresses methanation side reactions, improves carbon source conversion efficiency, and adapts to different water quality characteristics by flexibly adjusting operating parameters, providing a stable and reliable carbon source supply for subsequent phosphorus recovery and denitrification / phosphorus removal processes, thus optimizing the overall wastewater treatment process.

[0033] 2. This wastewater treatment equipment, which features staged carbon source release and simultaneous phosphorus recovery, achieves efficient enrichment and controllable release of phosphorus through multi-stage reaction tanks and dynamic sludge return channels. Through anaerobic-anoxic-aerobic multi-stage reactions and a side-flow phosphorus release tank, polyphosphate-accumulating bacteria release phosphate under anaerobic conditions and then over-absorb it under anoxic and aerobic conditions, achieving simultaneous nitrogen and phosphorus removal. The linkage between the ORP sensor and the sludge return ratio further ensures a phosphorus release efficiency of ≥80%, while mitigating the impact of system load fluctuations on phosphorus recovery. In this way, low-concentration phosphorus in the liquid phase is gradually concentrated, making subsequent chemical precipitation more efficient and avoiding the serious phosphorus resource loss problem in traditional methods. It achieves dynamic control and stable recovery of sludge-liquid phase phosphorus, providing a reliable guarantee for resource utilization.

[0034] 3. This wastewater treatment equipment, which features staged carbon source release and simultaneous phosphorus recovery, achieves efficient phosphorus crystallization and deep purification through a phosphorus separation and recovery unit combined with pH adjustment, precipitation reaction, and solid-liquid separation. CO2 aeration and NaOH fine-tuning control maintain the system pH between 8.5 and 9.0. The addition of Mg²⁺ / Ca²⁺ generates struvite or hydroxyapatite microcrystals. An inclined plate settler and micro-vortex flocculant promote rapid crystal aggregation and sedimentation. A ceramic membrane filter further removes residual suspended solids, ensuring a stable effluent TP ≤0.3 mg / L. An automated control system monitors parameters such as COD, TP, pH, and ORP in real time, dynamically adjusting reaction conditions and emergency carbon source addition to ensure stable year-round system operation and reduce manual intervention. This not only improves phosphorus resource recovery rate and product quality but also achieves deep wastewater purification and compliance with discharge standards, providing technical support for circular economy and environmental protection goals. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the system flow of the present invention;

[0037] Figure 2 This is a schematic diagram of the carbon source conversion unit of the present invention;

[0038] Figure 3 This is a schematic diagram of the phosphorus migration regulation unit of the present invention;

[0039] Figure 4 This is a schematic diagram of the phosphorus separation and recovery unit of the present invention;

[0040] Figure 5 This is a schematic diagram of the control system of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0042] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] like Figures 1 to 5As shown, the sewage treatment equipment for graded carbon source release and synchronous phosphorus recovery comprises a water inlet unit configured to receive carbon-containing organic sludge and sewage; a carbon source conversion unit communicated with the water inlet unit and configured to decompose carbon-containing organic matters into soluble small-molecular carbon sources; a phosphorus migration regulation and control unit communicated with the carbon source conversion unit, which adopts a multi-stage reaction tank structure and a dynamic sludge return channel and is configured to realize phosphorus enrichment and controlled release; a phosphorus separation and recovery unit communicated with the phosphorus migration regulation and control unit, which comprises a pH adjustment area, a precipitation reaction area and a solid-liquid separation area and is configured to realize crystallization precipitation and efficient recovery of phosphorus; a water outlet unit communicated with the phosphorus separation and recovery unit and configured to output water meeting standards; and an automatic control system connected with each of the above units and configured to cooperatively adjust operation parameters of each unit, so as to realize graded carbon source release and synchronous phosphorus recovery, wherein the automatic control system is further connected with an external SCADA / upper computer communication module for remote monitoring and data storage;

[0044] Sewage first enters the system through the water inlet unit, the organic sludge and pollutants contained therein are homogenized and then introduced into the carbon source conversion unit, where complex macromolecular organic matters are gradually decomposed into soluble small-molecular carbon sources through anaerobic fermentation or acid-producing reaction, such as volatile fatty acids. These small-molecular carbon sources can not only be quickly absorbed and utilized by microorganisms, but also provide sufficient energy and reducing power for subsequent phosphorus migration; then, the mixed solution containing soluble carbon sources is introduced into the phosphorus migration regulation and control unit, under the action of the multi-stage reaction tanks and the dynamic sludge return channel, the release and absorption of phosphorus in sludge are regulated, and the system can realize phosphorus enrichment, so that phosphorus with an original low concentration is gradually concentrated and enters a liquid phase in a controllable manner, thereby creating conditions for subsequent efficient recovery; when the mixed solution enters the phosphorus separation and recovery unit, the pH value of the system is adjusted chemically in the pH adjustment area first, so that phosphate ions react with ions such as calcium and magnesium to generate insoluble salts, then the crystallization reaction is completed and granular precipitates are formed in the precipitation reaction area, and then the precipitates are separated from the liquid through the solid-liquid separation area, thereby realizing efficient recovery and reuse of phosphorus; the treated clear liquid is discharged through the water outlet unit, ensuring that the effluent quality meets the discharge or reuse standards; the whole process is monitored and adjusted in real time by the automatic control system, the system collects operation data of each unit and interacts with the external SCADA / upper computer communication module to realize remote control and data storage, thereby ensuring that the process of graded carbon source release and synchronous phosphorus recovery is efficient, stable and traceable.

[0045] As Figure 1 , Figure 2 shown, the carbon source conversion unit comprises a series multi-stage reaction zone, and each reaction stage is provided with an independent stirring device and a temperature control system to realize graded release of carbon sources;

[0046] The multi-stage reaction zone is divided by function into:

[0047] Primary hydrolysis zone: temperature 35±1℃, HRT=6-8h, releases acetic acid and propionic acid;

[0048] Secondary acidification zone: temperature 45±1℃, HRT=10-12h, release butyric acid and valeric acid;

[0049] Level III stability zone: temperature 25±1℃, HRT=4-6h, carbon source COD concentration stabilized at 8000-10000mg / L;

[0050] Carbon-containing organic sludge / wastewater first enters the primary hydrolysis zone of a series multi-stage reaction chamber. Under conditions of independent stirring to maintain uniform mass transfer, depletion of dissolved oxygen, or maintenance at anaerobic / anoxic levels, the reaction temperature is stabilized at 35±1℃ and the HRT is controlled at 6–8h. This promotes the transformation of macromolecular organic matter into soluble products through hydrolysis, enzymatic hydrolysis, and primary fermentation, with an increased proportion of acetic acid and propionic acid, forming a VFA mixture dominated by readily available carbon. Subsequently, the mixture enters the secondary acidification zone at a set flow rate, where the temperature is increased and stabilized at 45±1℃, and the HRT is extended to 10–12h. Under stronger acidification drive and thorough mixing by independent stirring, the secondary acidification zone further enhances the acidification process. In the next stage, the acid-producing bacteria further convert the fermentable substrate into medium-chain volatile fatty acids (VFAs), increasing the proportions of butyric acid and valeric acid. Simultaneously, the higher temperature and acidification environment, which are detrimental to methanogens, inhibit carbon loss caused by methanation. The system completes a "fast carbon + slow carbon" phylogenetic expansion in this stage. After leaving the secondary stage, the material enters the tertiary stabilization zone, where the temperature drops to 25±1℃, the heat transfer time (HRT) is controlled at 4–6 h, and mixing is maintained through independent stirring. Further deep fermentation is achieved through "termination / passivation" at a lower temperature, preventing the continued consumption of the generated VFAs and achieving homogenization of the output. This stabilizes the soluble COD concentration at 8000–10000. Within the target range of mg / L, the system simultaneously mitigates the impact of temperature and acidity on downstream units. Throughout the series system, online monitoring of each segment (such as temperature, ORP / pH, flow rate, and necessary COD / VFA checks) provides feedback to the controller. Based on this feedback, the controller adjusts the stirring intensity, heating / heat exchange, and flow rate ratio of each segment to ensure that the "staged release" rhythm meets the set VFA composition and concentration targets. Ultimately, a stable, predictable, and tunable liquid carbon source is delivered to subsequent phosphorus migration regulation or biological nitrogen and phosphorus removal units, achieving precise domestication and efficient driving of downstream processes.

[0051] The acid production reaction module of the carbon source conversion unit is configured with:

[0052] Acidification bacterial inoculation area: equipped with immobilized compound bacterial agent containing Clostridium and Bacillus;

[0053] Acidity monitoring device: used to detect VFA composition in real time and feed it back to the control system. When the butyric acid content is greater than 40%, the HRT of the secondary acidification zone is automatically extended to 14 hours.

[0054] After carbonaceous organic sludge enters the acidifying bacteria inoculation zone, the immobilized composite bacterial agent (containing Clostridium and Bacillus) rapidly attaches and grows under anaerobic conditions. Clostridium hydrolyzes macromolecular organic matter (such as cellulose and protein) into soluble substrates and preferentially synthesizes butyric acid through the β-oxidation pathway. Bacillus metabolizes to produce small amounts of acetic acid and propionic acid. The mixed VFAs are carried into the secondary acidification zone by the water flow. At this time, the acidity monitoring device detects the VFA composition in real time through high-performance liquid chromatography (HPLC) or near-infrared spectroscopy. When the butyric acid concentration exceeds 40% (i.e., butyric acid / total VFA > 0.4), the control system immediately extends the hydraulic retention time (HRT) from the default 10-12h to 14h. During this extended period, Clostridium continues to convert residual substrates into butyric acid, so that the butyric acid concentration in the final effluent is stabilized at 2500-3000 mg / L (accounting for a percentage of total VFA). The concentration of acetic acid produced by Bacillus metabolism is maintained at 1800-2000 mg / L (accounting for 30-35%). If the butyric acid content is found to be below the threshold (e.g., the influent carbon source is mainly sugar, leading to acetic acid dominance), the standard HRT (10-12 h) is maintained. At this time, the acetic acid content rises to 60-70%, meeting the requirements for rapid nitrogen removal. Throughout the process, the microporous structure (pore size 0.2 μm) on the carrier surface blocks the invasion of methanogenic bacteria (size > 1 μm), keeping the methane yield below 5%. The final output VFA mixture has a stable COD of 8000-10000 mg / L. The ratio of butyric acid to acetic acid can be flexibly switched from 40:60 to 50:50 by dynamic adjustment of HRT according to the downstream process requirements (nitrogen removal priority or phosphorus release priority).

[0055] like Figure 1 , Figure 3 As shown, the multi-stage reaction tank structure includes an anaerobic tank, an anoxic tank, and an aerobic tank arranged sequentially, with a PAOs biofilm carrier at the end of the aerobic tank; the dynamic sludge return channel includes a side-flow phosphorus release tank, which releases phosphorus from 10% of the returned sludge under anaerobic conditions for 2 hours before returning it to the anaerobic tank, with a phosphorus release rate ≥80%. The dynamic sludge return channel adjusts the return ratio R based on the real-time value of the oxidation-reduction potential sensor. When ORP ≥ -150 mV, the return ratio R is 80%; when ORP < -250 mV, the return ratio R is 150%.

[0056] Wastewater first enters the anaerobic tank. Under strict anaerobic conditions, polyphosphate-accumulating organisms (PAOs) release stored phosphates using volatile fatty acids (VFAs) provided by the carbon source conversion unit, increasing the phosphorus concentration in the liquid phase. The mixed liquor then enters the anoxic tank, where denitrifying bacteria reduce nitrates to nitrogen. Simultaneously, some PAOs use nitrates as electron acceptors to absorb phosphates, achieving simultaneous nitrogen and phosphorus removal. Afterward, the wastewater flows into the aerobic tank, where PAOs, under sufficient oxygen conditions, excessively absorb phosphates, forming high-phosphorus sludge. The PAO biofilm carrier at the end of the aerobic tank further enriches polyphosphate-accumulating organisms, enhancing the system's load-bearing capacity. The sludge return system returns a portion of the sludge from the end of the aerobic tank to the anaerobic tank. 10% of the sludge enters the side-flow phosphorus release tank and remains for 2 hours under strict anaerobic conditions (ORP < -250mV) to fully release phosphate from PAOs, achieving a phosphorus release rate of ≥80%. The phosphorus-released sludge is then returned to the anaerobic tank to continue the cycle. The ORP sensor monitors the oxidation-reduction potential of the anaerobic tank in real time. When ORP ≥ -150mV, the control system sets the return ratio to 80% to maintain normal operation. When ORP < -250mV, it indicates a high phosphorus load in the system, and the return ratio is automatically increased to 150% to enhance the phosphorus release effect. Finally, the phosphorus-rich liquid phase enters the phosphorus separation and recovery unit, where phosphorus resources are recovered through chemical precipitation and solid-liquid separation, while the effluent meets the discharge standards.

[0057] like Figure 1 , Figure 4 As shown, the pH adjustment zone uses CO2 aeration and NaOH fine-tuning to maintain pH=8.5-9.0, and MgCl2 / Ca(OH)2 is added to generate struvite or hydroxyapatite to promote the formation and precipitation of struvite or hydroxyapatite.

[0058] The precipitation reaction zone is equipped with an inclined plate precipitator and a micro vortex flocculant to accelerate particle aggregation and sedimentation.

[0059] The solid-liquid separation zone uses a ceramic membrane filter with a pore size of 0.1 μm to remove residual suspended solids and colloidal particles.

[0060] The phosphorus-containing liquid phase first enters the pH adjustment zone, where the initial pH is slowly lowered from acidic or neutral to 8.0-8.5 by CO2 aeration. Then, NaOH is used for fine-tuning to the target pH of 8.5-9.0. During this process, MgCl2 or Ca(OH)2 (selected according to the ammonium nitrogen concentration in the water) is added, causing phosphate ions (PO4³⁻) to react with Mg²⁺ / Ca²⁺ to form struvite or hydroxyapatite microcrystals. The mixed liquid then enters the sedimentation reaction zone. The inclined plate settler, with its multi-layered inclined plate structure, increases the effective settling area, allowing crystal nuclei to settle rapidly. Simultaneously, the micro-vortex flocculant generates microscale eddies, promoting the collision and growth of tiny crystals into dense flocs (50-100 μm in diameter), significantly increasing the settling velocity. After sedimentation... The supernatant flows into the solid-liquid separation zone, where it is precisely sieved by a ceramic membrane filter (0.1μm pore size), completely removing residual suspended solids and colloidal phosphorus. The purified effluent has a stable TP concentration of ≤0.3mg / L. The sludge (rich in struvite or hydroxyapatite) in the sedimentation zone is periodically discharged into the phosphorus product collection system. After dehydration and drying, it can be used as a raw material for slow-release phosphate fertilizer. Throughout the process, the coordinated regulation of CO2 and NaOH avoids drastic pH fluctuations, and the periodic backwashing of the ceramic membrane ensures long-term flux stability, ultimately achieving efficient phosphorus recovery and deep effluent purification.

[0061] like Figure 1 , Figure 5 As shown, the automated control system executes a carbon-phosphorus synergistic strategy, which includes the following steps:

[0062] S1: Based on historical C / N / P data of the influent, predict the carbon source demand and dynamically adjust the HRT of the multi-stage reaction zone to match the carbon source demand of the influent;

[0063] S2: Based on the TP concentration at the end of the aerobic tank, control the Mg / Ca molar ratio for struvite / hydroxyapatite crystallization to maintain crystallization efficiency;

[0064] S3: When the TP of the effluent from the solid-liquid separation zone is greater than 0.5 mg / L, activate the emergency carbon source storage tank to add sodium acetate to ensure that the effluent meets the standards stably;

[0065] The automated control system collects historical C / N / P data of the influent in real time, and combines this with online monitoring of COD, TP, and NH4⁺ concentrations. Using a built-in algorithm, it predicts the current carbon source demand and dynamically adjusts the HRT (6-14h) of the multi-stage reaction zone in the carbon source conversion unit to ensure that the release ratio of short-chain (acetic acid) and long-chain (butyric acid) VFAs matches the downstream nitrogen and phosphorus removal needs. Simultaneously, the system continuously monitors the TP concentration at the end of the aerobic tank. When TP ≥ 50 mg / L, it automatically increases the MgCl2 dosage (Mg:PO4 = 1.2:1) to promote rapid struvite crystallization. When TP < 50 mg / L, it automatically increases the dosage. When the concentration of phosphorus in the solid-liquid separation zone is g / L, reduce the amount of MgCl2 (Mg:PO4=1:1) to avoid waste of reagents; if the TP in the effluent from the solid-liquid separation zone is still >0.5mg / L, the system immediately activates the emergency carbon source storage tank and adds sodium acetate (200-300mg / L) to the anoxic tank to stimulate PAOs to absorb phosphorus for the second time, ensuring that the final effluent TP is ≤0.3mg / L; the whole process does not require manual intervention. The control system records data in real time through the SCADA platform and optimizes operating parameters to form a closed-loop management of "monitoring → prediction → adjustment → verification", realizing efficient synergy between carbon source staged release and phosphorus recovery.

[0066] like Figure 1 , Figure 5 As shown, the automated control system further includes an online monitoring module, which is equipped with a pH sensor, an ORP sensor, an online COD analyzer, and a total phosphorus monitor to realize real-time monitoring and feedback adjustment of the operating status of the multi-stage reaction zone and the phosphorus separation and recovery unit.

[0067] The online monitoring module collects real-time pH data from the carbon source conversion unit and phosphorus separation and recovery unit via a pH sensor. When the pH deviates from the set range (8.5-9.0), the control system automatically adjusts the CO2 aeration rate or NaOH dosage to ensure a stable struvite crystallization environment. The ORP sensor continuously monitors the oxidation-reduction potential of the anaerobic tank and the side-flow phosphorus release tank. If the ORP < -250mV, the sludge return ratio is immediately increased to 150% to enhance phosphorus release, and a signal is simultaneously fed back to the control system to record abnormal operating conditions. The online COD analyzer measures the carbon source concentration every 5 minutes and, based on historical data, predicts the required carbon concentration. The system is designed to dynamically adjust the HRT (Heat-Resistance Time) of each reaction zone (e.g., shorten the HRT to 6 hours when COD > 8000 mg / L); the total phosphorus monitor is equipped with dual monitoring points at the end of the aerobic tank and the effluent outlet. When the TP in the aerobic tank is detected to be > 50 mg / L, the MgCl2 dosage is increased (Mg:PO4 = 1.2:1). If the effluent TP is > 0.5 mg / L, the emergency carbon source is activated; all data is transmitted to the SCADA platform via the Industrial Internet of Things to generate real-time trend charts and early warning reports. Maintenance personnel can remotely calibrate sensors or switch to backup equipment via the host computer to ensure uninterrupted and stable operation of the system throughout the year.

[0068] like Figure 1 ... Figure 4 , Figure 5 As shown, the carbon source conversion unit, phosphorus migration control unit and phosphorus separation and recovery unit are coupled into an integrated device through pipelines, and each unit is provided with a bypass pipeline and a switching valve. The bypass pipeline is used to isolate the faulty unit during equipment maintenance so as to flexibly switch between continuous flow mode and batch mode.

[0069] After entering the integrated device through the influent unit, the wastewater first flows through the three-stage reaction zone of the carbon source conversion unit (hydrolysis → acidification → stabilization). In continuous flow mode, each unit operates in series through the main pipeline. The mixed liquor after carbon source conversion sequentially enters the phosphorus migration control unit (anaerobic → anoxic → aerobic) and the phosphorus separation and recovery unit (pH adjustment → sedimentation → solid-liquid separation), ultimately achieving the required effluent quality. When a unit requires maintenance (such as replacing the acidifying bacteria in the carbon source conversion unit), the operator closes the inlet and outlet valves of that unit and opens the bypass pipeline, allowing the wastewater to bypass the faulty unit and enter the next stage. At this time, the system automatically switches to batch mode, compensating for the treatment capacity by adjusting the influent flow and retention time (such as extending the HRT of the aerobic tank) to ensure that the effluent quality does not deteriorate. After maintenance is completed, the valves switch back to the main pipeline, and the system resumes continuous flow operation. If a sudden change in influent load is detected (such as a sudden increase in COD), the control system can automatically activate the bypass to temporarily store some high-concentration wastewater in the batch buffer tank to avoid impacting the core unit. All pipeline interfaces adopt a flange quick-connect design, supporting module replacement or expansion within 1 hour.

[0070] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0071] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A wastewater treatment device for staged carbon source release and simultaneous phosphorus recovery, characterized in that, include: The inlet unit is used to receive carbonaceous organic sludge and wastewater; A carbon source conversion unit is connected to the water inlet unit. The carbon source conversion unit includes a series multi-stage reaction zone. Each reaction zone is equipped with an independent stirring device and a temperature control system to realize the staged release of carbon source. The multi-stage reaction zone is functionally divided as follows: Primary hydrolysis zone: temperature 35±1℃, HRT=6-8h, releases acetic acid and propionic acid; Secondary acidification zone: temperature 45±1℃, HRT=10-12h, release butyric acid and valeric acid; Level III stability zone: temperature 25±1℃, HRT=4-6h, carbon source COD concentration stabilized at 8000-10000mg / L, used to decompose carbon-containing organic matter into soluble small molecule carbon sources; Alternatively, the carbon source conversion unit may be configured as an acid-producing reaction module, which includes an acidifying bacteria inoculation zone and an acidity monitoring device. The acidifying bacteria inoculation zone is equipped with an immobilized composite bacterial agent containing Clostridium and Bacillus. The discharge end of the acidifying bacteria inoculation zone is connected to the feed end of the secondary acidification zone. The acidity monitoring device is located in the secondary acidification zone and connected to the automated control system. It is used to detect the VFA composition in the secondary acidification zone in real time and feed the detection results back to the automated control system. When the butyric acid content is greater than 40%, the automated control system extends the hydraulic retention time of the secondary acidification zone to 14 hours. The phosphorus migration control unit, connected to the carbon source conversion unit, employs a multi-stage reaction tank structure and a dynamic sludge return channel to achieve phosphorus enrichment and controlled release. The multi-stage reaction tank structure includes an anaerobic tank, an anoxic tank, and an aerobic tank arranged sequentially, with a PAOs biofilm carrier at the end of the aerobic tank. The dynamic sludge return channel includes a side-flow phosphorus release tank, which releases 10% of the returned sludge under anaerobic conditions for 2 hours before returning it to the anaerobic tank, achieving a phosphorus release rate ≥80%. The dynamic sludge return channel adjusts the return ratio R based on real-time values ​​from an oxidation-reduction potential sensor. When ORP ≥ -150 mV, the return ratio R is 80%; when ORP < -250 mV, the return ratio R is 150%. The phosphorus separation and recovery unit, connected to the phosphorus migration control unit, includes a pH adjustment zone, a precipitation reaction zone, and a solid-liquid separation zone, and is used to achieve phosphorus crystallization precipitation and efficient recovery. The effluent unit is connected to the phosphorus separation and recovery unit and is used to output qualified water; An automated control system, connected to the aforementioned units, is used to adjust the operating parameters of each unit in a coordinated manner to achieve graded release of carbon sources and simultaneous recovery of phosphorus.

2. The wastewater treatment equipment for staged carbon source release and simultaneous phosphorus recovery according to claim 1, characterized in that, The pH adjustment zone uses CO2 aeration and NaOH fine-tuning to maintain pH=8.5-9.0, and MgCl2 / Ca(OH)2 is added to generate struvite or hydroxyapatite to promote the formation and precipitation of struvite or hydroxyapatite. The precipitation reaction zone is equipped with an inclined plate precipitator and a micro vortex flocculant to accelerate particle aggregation and sedimentation. The solid-liquid separation zone uses a ceramic membrane filter with a pore size of 0.1 μm to remove residual suspended solids and colloidal particles.

3. The wastewater treatment equipment for staged carbon source release and simultaneous phosphorus recovery according to claim 1, characterized in that, The automated control system implements a carbon-phosphorus synergistic strategy, which includes the following steps: S1: Based on historical C / N / P data of the influent, predict the carbon source demand and dynamically adjust the HRT of the multi-stage reaction zone to match the carbon source demand of the influent. S2: Based on the TP concentration at the end of the aerobic tank, control the Mg / Ca molar ratio for struvite / hydroxyapatite crystallization to maintain crystallization efficiency; S3: When the TP of the effluent from the solid-liquid separation zone is greater than 0.5 mg / L, activate the emergency carbon source storage tank to add sodium acetate to ensure that the effluent meets the standards stably.

4. The wastewater treatment equipment for staged carbon source release and simultaneous phosphorus recovery according to claim 3, characterized in that, The automated control system further includes an online monitoring module, which is equipped with a pH sensor, an ORP sensor, an online COD analyzer, and a total phosphorus monitor to achieve real-time monitoring and feedback adjustment of the operating status of the multi-stage reaction zone and the phosphorus separation and recovery unit.

5. The wastewater treatment equipment for staged carbon source release and simultaneous phosphorus recovery according to claim 1, characterized in that, The carbon source conversion unit, phosphorus migration control unit, and phosphorus separation and recovery unit are coupled into an integrated device through pipelines, and each unit is provided with a bypass pipeline and a switching valve. The bypass pipeline is used to isolate the faulty unit during equipment maintenance so as to flexibly switch between continuous flow mode and batch mode.

6. The wastewater treatment equipment for staged carbon source release and simultaneous phosphorus recovery according to claim 1, characterized in that, The automated control system is further connected to an external SCADA / host computer communication module for remote monitoring and data storage.

Images