An adaptive control method, system and application for magnetic flocculation reaction process

Abstract

This invention provides an adaptive control method, system, and application for a magnetic flocculation reaction process, relating to the field of wastewater treatment. The method includes the following steps: S1, filtering wastewater, then, based on monitored water quality data, adding biomass magnetic seeds and superparamagnetic nanobubbles to the wastewater to obtain a mixed solution; S2, dispersing the mixed solution in two stages; S3, magnetically separating the products after the two-stage dispersion to obtain treated wastewater and magnetic flocs; S4, performing stepwise desorption of the recovered biomass magnetic seeds. Based on the prepared biomass magnetic seeds, this method provides a novel and reliable pathway for addressing complex water pollution problems, and the one-step treatment effectively improves water treatment efficiency.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to an adaptive control method, system and application for magnetic flocculation reaction process. Background Technology

[0002] Currently, water pollution is evolving from single pollutant forms to complex pollution patterns. Among these, the problem of complex pollution formed by emerging pollutants such as microplastics and traditional heavy metal ions is becoming increasingly prominent. Microplastics have small particle sizes, strong hydrophobicity, and densities close to those of water, making them inefficient to remove using traditional sedimentation and filtration processes. Meanwhile, heavy metal ions have high solubility and biotoxicity, and when the two coexist, they are more likely to form complex pollutant clusters, further increasing the difficulty of remediation.

[0003] Magnetic separation technology has shown great potential in the field of water treatment due to its high efficiency and speed. The core of this technology lies in magnetic seeds, which adsorb pollutants and then utilize an external magnetic field to achieve rapid solid-liquid separation. Currently, mainstream magnetic flocculation technologies generally employ a combined "magnetic seed-flocculator" process. This involves first adding inorganic or composite magnetic seeds to the wastewater to adsorb target pollutants, then adding flocculants such as polyaluminum chloride (PAC) and polyacrylamide (PAM). Through charge neutralization and bridging, magnetic flocs are formed, and finally, magnetic separation is performed.

[0004] However, this existing technology system has several inherent drawbacks. First, its process is lengthy, relying on multi-step dosing operations, requiring precise control of the dosing sequence and ratio of magnetic seeds and flocculants, resulting in complex operation and control, and a large reactor footprint. Second, the introduction of large amounts of exogenous inorganic flocculants (such as PAC) leads to a significant increase in chemical sludge production, resulting in high subsequent sludge disposal costs and the risk of secondary pollution. Furthermore, the existing magnetic seeds have relatively simple functional designs, generally lacking sufficient affinity for hydrophobic microplastics, making it difficult to achieve simultaneous and efficient removal when dealing with microplastic-heavy metal complex pollution, often resulting in one aspect being neglected. In addition, most magnetic seeds face problems such as oxidation of magnetic components, passivation of active sites, or shedding of the surface functional layer during recycling, causing their adsorption capacity and magnetic responsiveness to decline sharply after several cycles, resulting in a limited service life.

[0005] Therefore, existing magnetic flocculation technology faces technical bottlenecks when dealing with complex microplastic and heavy metal pollution, such as complex process flow, large chemical sludge production, insufficient ability to synergistically remove complex pollutants, and poor material stability. There is an urgent need to develop a more integrated, efficient, and environmentally friendly new solution.

[0006] Therefore, this invention is proposed. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides an adaptive control method, system, and application for the magnetic flocculation reaction process. Based on the prepared biomass magnetic seeds, this method can provide a new and reliable pathway for addressing pollution problems in complex water bodies, while the one-step treatment approach can effectively improve water treatment efficiency.

[0008] In order to achieve the objective of this invention, the following technical solution is adopted:

[0009] This invention provides an adaptive control method for a magnetic flocculation reaction process, comprising the following steps:

[0010] S1. Filter the wastewater, and then, based on the water quality data obtained from monitoring, add biomass magnetic seeds and superparamagnetic nanobubbles to the wastewater to obtain a mixed liquid.

[0011] S2. The mixture is dispersed in two stages;

[0012] S3. The products after the two-stage dispersion are magnetically separated to obtain treated wastewater and magnetic flocs.

[0013] S4. The recovered biomass magnetic seeds are desorbed in a stepwise manner.

[0014] Furthermore, the specific steps of the two-stage dispersion in step S2 include:

[0015] S201. Disperse the mixture at 300±50 rpm for 2±0.5 min;

[0016] S202, then dispersed at 50±20 rpm for 5±1 min.

[0017] Furthermore, the specific steps of the stepwise desorption in step S4 include:

[0018] S401. Use a compound enzyme solution and stir at 40°C for 20 minutes.

[0019] S402, then use 0.05 mol / L dilute nitric acid solution and stir for 10 min at room temperature;

[0020] S403 was then washed five times alternately with deionized water and ethanol, and then vacuum dried at 40°C.

[0021] Furthermore, the dosage of the biomass magnetic seed is 50 mg / L-150 mg / L;

[0022] The amount of the superparamagnetic nanobubbles used is 50 mg / L-150 mg / L.

[0023] Furthermore, the complex enzyme is a mixture of 0.5 wt% lipase and 0.5 wt% protease in a volume ratio of 1:1.

[0024] Furthermore, the protease is an alkaline protease.

[0025] Furthermore, the biomass magnetic seed consists of an outermost shell, a middle layer, and a core.

[0026] The core is a modified magnetic nanocluster;

[0027] The intermediate layer is agricultural waste;

[0028] The shell layer is a polylactic acid-polyethyleneimine copolymer;

[0029] Of which, by weight percentage, the core content is 10%-25%;

[0030] The middle layer accounts for 60%-80%;

[0031] Shell layer 10%-20%.

[0032] Furthermore, the method for preparing the superparamagnetic nanobubbles includes:

[0033] A. Disperse Fe3O4 in PBS buffer containing 1 wt% phospholipids;

[0034] B. Subsequently, under 400W power and ice bath conditions, inert protective gas was introduced into the solution, and ultrasonic treatment was carried out for 3-5 minutes.

[0035] Furthermore, the magnetic field strength for magnetic separation in step S3 is 0.8T-1.2T; the magnetic separation time is ≤1min.

[0036] This invention also provides an application of an adaptive control method for the magnetic flocculation reaction process in wastewater treatment.

[0037] The present invention also provides a system using the above-described adaptive control method for the magnetic flocculation reaction process.

[0038] The present invention has the following technical effects:

[0039] The technical solution provided by this invention demonstrates outstanding comprehensive performance in practice. This method exhibits significant synergistic removal capabilities in complex pollution systems where microplastics and heavy metals coexist. It achieves a removal rate of over 95% for microplastics such as polyethylene and polypropylene with particle sizes smaller than 100 micrometers, while simultaneously achieving a removal rate of over 98% for heavy metal ions such as lead and cadmium. Under the influence of an external magnetic field, rapid and complete separation can be achieved within two minutes, greatly improving water treatment efficiency. This technology provides a new and reliable path for efficiently, economically, and sustainably solving complex water pollution problems. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 Process flow diagram of adaptive control method for magnetic flocculation reaction. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0043] In a first aspect, the present invention provides an adaptive control method for a magnetic flocculation reaction process, comprising the following steps:

[0044] S1. Filter the wastewater, and then, based on the water quality data obtained from monitoring, add biomass magnetic seeds and superparamagnetic nanobubbles to the wastewater to obtain a mixed liquid.

[0045] S2. The mixture is dispersed in two stages;

[0046] S3. The products after the two-stage dispersion are magnetically separated to obtain treated wastewater and magnetic flocs.

[0047] S4. The recovered biomass magnetic seeds are desorbed in a stepwise manner.

[0048] This invention uses specific biomass magnetic seeds as the core reagent, integrating adsorption (microplastics and heavy metals), flocculation (through its shell design), and magnetic separation functions. Simultaneously, superparamagnetic nanobubbles are introduced as "magnetic nuclei," significantly enhancing the floc formation rate, structural density, and magnetic responsiveness through synergistic effects with the biomass magnetic seeds. The traditional multi-step process of "adding magnetic seeds - adding flocculant - slow flocculation - magnetic separation" is simplified to a one-step process of "adding two functional materials - two-stage dispersion - magnetic separation." Through stepwise desorption, the regeneration of magnetic seeds and the separate recovery of pollutants are achieved, embodying an advanced concept of resource utilization.

[0049] In some embodiments, the specific steps of the two-stage dispersion in step S2 include:

[0050] S201. Disperse the mixture at 300±50 rpm for 2±0.5 min;

[0051] S202, then dispersed at 50±20 rpm for 5±1 min.

[0052] High-speed dispersion is carried out at a relatively high speed of around 300 rpm. During this process, the biomass magnetic seeds disperse rapidly. The PLA segments strongly capture microplastics through hydrophobic interactions, and the PEI segments complex heavy metal ions through amine groups. This enables the biomass magnetic seeds and superparamagnetic bubbles to disperse rapidly and uniformly in wastewater, ensuring that they collide and adsorb with pollutants (microplastics, heavy metal ions) fully and quickly.

[0053] Reduce the rotation speed to around 50 rpm to create a mild fluid environment. At this point, the PDADMAC chain segments of the magnetic seed shell begin to play a dominant role, aggregating the individual magnetic seed particles and nanobubbles that have already adsorbed pollutants through charge neutralization and adsorption bridging, forming larger, denser, and easily magnetically separable "self-generated flocs" with a particle size of 0.5-2 mm.

[0054] In some embodiments, the specific steps of the stepwise desorption in step S4 include:

[0055] S401. Use a compound enzyme solution and stir at 40°C for 20 minutes.

[0056] S402, then use 0.05 mol / L dilute nitric acid solution and stir for 10 min at room temperature;

[0057] S403 was then washed five times alternately with deionized water and ethanol, and then vacuum dried at 40°C.

[0058] In this process, the first step is enzymatic hydrolysis, using a complex solution of lipase and protease to specifically degrade the hydrophobic segments of polylactic acid (PLA) in the magnetic seed shell. PLA is key to capturing microplastics; after its degradation, the adsorbed microplastics can be released and recovered. This step is gentle and specific, effectively avoiding damage to the magnetic seed structure.

[0059] The second step involves acid washing with dilute nitric acid to desorb heavy metal ions (such as Pb) fixed on the polyethyleneimine (PEI) segments through complexation. 2+ Cd 2+ An acidic environment causes amines to protonate, weakening their coordination ability with heavy metals, thereby enabling the recovery of heavy metals.

[0060] It achieves the classification and targeted recovery of microplastics and heavy metals; the mild desorption conditions maximize the protection of the magnetic core and main structure of the magnetic seeds, ensuring their cycle stability; through stepwise desorption, mutual interference of pollutants is avoided, ensuring their respective high desorption efficiency and recovery purity.

[0061] In some embodiments, the amount of biomass magnetic seed used is 50 mg / L-150 mg / L;

[0062] The amount of the superparamagnetic nanobubbles used is 50 mg / L-150 mg / L.

[0063] The dosage of biomass magnetic seeds is limited to ensure sufficient adsorption and flocculation sites under most pollution loads, while avoiding waste and potential siltation caused by excessive addition.

[0064] The dosage of superparamagnetic nanobubbles was precisely controlled, representing a crucial and innovative low-dose approach. Their role is not to provide primary adsorption sites, but rather to act as "nuclei" and "bridges," significantly altering the physical properties of the flocs at extremely low concentrations, thereby achieving better adsorption performance.

[0065] In some embodiments, the complex enzyme is a mixture of 0.5 wt% lipase and 0.5 wt% protease in a volume ratio of 1:1.

[0066] In some embodiments, the protease is an alkaline protease.

[0067] Lipase and protease exhibit highly efficient catalytic degradation activity against ester bonds and potential protein impurities in PLA segments, respectively. Their combination allows for a more thorough and rapid disintegration of the hydrophobic shell, releasing microplastics. This composite enzyme system ensures efficient and rapid release of microplastics, while the bio-enzyme acts as a desorbent, avoiding the use of strong acids, strong alkalis, or organic solvents, making the process environmentally friendly.

[0068] In some embodiments, the biomass magnetic seed consists of an outermost shell, a middle layer, and a core;

[0069] The core is a modified magnetic nanocluster;

[0070] The intermediate layer is agricultural waste;

[0071] The shell layer is a polylactic acid-polyethyleneimine copolymer;

[0072] Of which, by weight percentage, the core content is 10%-25%;

[0073] The middle layer accounts for 60%-80%;

[0074] Shell layer 10%-20%.

[0075] The "core-shell-intermediate layer" structure of this biomass magnetic species can provide separation driving force, while increasing specific surface area and stabilizing the framework. Each layer performs its own function and works together to ensure its synergistic removal capability of complex pollutants.

[0076] In some embodiments, the method for preparing the superparamagnetic nanobubbles includes:

[0077] A. Disperse Fe3O4 in PBS buffer containing 1 wt% phospholipids;

[0078] B. Subsequently, under 400W power and ice bath conditions, inert protective gas was introduced into the solution, and ultrasonic treatment was carried out for 3-5 minutes.

[0079] Phospholipids, as surfactants, form a stable bilayer at the gas-liquid interface under ultrasonic cavitation, anchoring magnetic nanoparticles onto the bubble shell, thus forming stable magnetic nanobubbles. This process produces nanobubbles with uniform particle size and good stability, which can synergistically work with biomass magnetic seeds to enhance the system's ability to treat wastewater.

[0080] In some embodiments, the magnetic field strength for magnetic separation in step S3 is 0.8T-1.2T; and the magnetic separation time is ≤1min.

[0081] A magnetic field strength of 0.8-1.2T is sufficient to generate a strong magnetic force on the formed magnetic flocs, enabling them to be rapidly captured and separated in an extremely short time of ≤1 minute, far faster than traditional gravity sedimentation (which typically takes tens of minutes to several hours). This significantly improves water treatment throughput and efficiency. The rapid separation reduces the residence time of the flocs in the water, avoiding breakage and resuspension, and ensuring low turbidity in the effluent. This allows for equipment miniaturization and weight reduction, significantly lowering operating costs and better aligning with the concept of green chemistry.

[0082] Secondly, this invention provides an application of an adaptive control method for the magnetic flocculation reaction process in wastewater treatment.

[0083] Thirdly, the present invention provides a system using the above-described adaptive control method for the magnetic flocculation reaction process.

[0084] The following is a detailed explanation using specific embodiments:

[0085] Example 1

[0086] The relevant parameters of the biomass magnetic seed used in this embodiment have been disclosed in patent CN120838390A.

[0087] S1. Preparation of superparamagnetic nanobubbles: Fe3O4 was dispersed in PBS buffer containing 1 wt% phospholipids, and then nitrogen gas was introduced into the solution using an ultrasonic cell disruptor at 400W power and under ice bath conditions. The mixture was ultrasonically treated for 5 minutes to form superparamagnetic nanobubbles with a particle size distribution of 100-500 nm.

[0088] S2. Filter the wastewater to remove larger particles. Then, based on the water quality data obtained from monitoring, under relatively good water quality conditions, add biomass magnetic seeds to the wastewater at a dosage of 50 mg / L, and simultaneously add superparamagnetic nanobubbles to the wastewater at a dosage of 50 mg / L to obtain a mixed solution.

[0089] S3. Disperse the mixture at 300 rpm for 2 minutes, then at 50 rpm for 5 minutes, and then proceed to the separation zone for magnetic separation.

[0090] S4. The disks in the separation zone are made of neodymium iron boron permanent magnets with a rotation speed of 2-5 rpm and a magnetic field strength of 0.8T on the disk surface. Magnetic flocs are captured by the disks, and the treated wastewater undergoes further treatment.

[0091] S5. Preparation of compound enzyme solution: Mix 0.5wt% lipase and 0.5wt% alkaline protease in a 1:1 volume ratio, add the compound enzyme solution to the magnetic flocs, and stir at 40°C for 20 min; then use 0.05 mol / L dilute nitric acid solution and stir at room temperature for 10 min.

[0092] S6. Subsequently, the magnetic seeds were washed 5 times with alternating ethanol and deionized water, once with ethanol and once with deionized water. The washed magnetic seeds were then vacuum dried at 40°C for 6 hours to obtain biomass magnetic seeds, which can be reused in the reaction system.

[0093] The flowchart of the method is as follows Figure 1 As shown.

[0094] Example 2

[0095] The relevant parameters of the biomass magnetic seed used in this embodiment have been disclosed in patent CN120838390A.

[0096] S1. Preparation of superparamagnetic nanobubbles: Fe3O4 was dispersed in PBS buffer containing 1 wt% phospholipids, and then nitrogen gas was introduced into the solution using an ultrasonic cell disruptor at 400W power and under ice bath conditions. The mixture was ultrasonically treated for 5 minutes to form superparamagnetic nanobubbles with a particle size distribution of 100-500 nm.

[0097] S2. Filter the wastewater to remove larger particles. Then, based on the water quality data obtained from monitoring, under poor water quality conditions, add biomass magnetic seeds to the wastewater at a dosage of 150 mg / L, and at the same time add superparamagnetic nanobubbles to the wastewater at a dosage of 150 mg / L to obtain a mixed solution.

[0098] S3. Disperse the mixture at 350 rpm for 2 minutes, then disperse at 70 rpm for 5 minutes, and then enter the separation zone for magnetic separation.

[0099] S4. The disks in the separation zone are made of neodymium iron boron permanent magnets with a rotation speed of 2-5 rpm and a magnetic field strength of 1.2T on the disk surface. Magnetic flocs are captured by the disks, and the treated wastewater undergoes further treatment.

[0100] S5. Preparation of compound enzyme solution: Mix 0.5wt% lipase and 0.5wt% alkaline protease in a 1:1 volume ratio, add the compound enzyme solution to the magnetic flocs, and stir at 40°C for 20 min; then use 0.05 mol / L dilute nitric acid solution and stir at room temperature for 10 min.

[0101] S6. Subsequently, the magnetic seeds were washed 5 times with alternating ethanol and deionized water, once with ethanol and once with deionized water. The washed magnetic seeds were then vacuum dried at 40°C for 6 hours to obtain biomass magnetic seeds, which can be reused in the reaction system.

[0102] Experimental Example 1: Recovery Rate of Magnetic Seeds

[0103] Experimental objective: To calculate the physical recovery rate of biomagnetic seeds by accurately measuring the mass change of the seeds before and after the entire operation process.

[0104] Experimental methods:

[0105] Initial quality record (M0)

[0106] Take a sample of the newly prepared biomagnetic seed and vacuum dry it to constant weight at 40°C.

[0107] The mass of the sample was accurately measured using an analytical balance and recorded as M0 (5.0000 g). This is the initial mass for the cyclic experiment.

[0108] 2. First adsorption-separation cycle

[0109] Adsorption:

[0110] A magnetic seed of mass M0 was added to 250 mL of simulated wastewater, and the adsorption reaction was carried out as described in Example 1.

[0111] Magnetic separation and collection:

[0112] After the reaction is complete, use a strong magnet for magnetic separation and carefully pour off the supernatant.

[0113] Initial wet weight weighing (M) wet ):

[0114] Transfer all the wet magnetic seed flocs that have adsorbed pollutants onto a pre-weighed petri dish or filter paper, weigh the total mass, and record it as M. wet .

[0115] washing:

[0116] Gently wash the surface of the magnetic seeds with a small amount of deionized water to remove impurities that have not been firmly adsorbed.

[0117] 3. Step-by-step desorption and regeneration

[0118] Enzymatic hydrolysis:

[0119] The magnetic seeds were dispersed in the complex enzyme solution and gently stirred at 40°C for 20 minutes to desorb the microplastics.

[0120] Pickling:

[0121] After magnetic separation, the magnetic seeds are dispersed in a dilute nitric acid solution and stirred at room temperature for 10 minutes to desorb heavy metals.

[0122] Thoroughly wash:

[0123] Wash the magnetic seeds three times each with deionized water and ethanol alternately to thoroughly remove the desorbent and residual contaminants.

[0124] dry:

[0125] The washed magnetic seeds were vacuum dried at 40°C to constant weight.

[0126] Dry weight (M1) after the first cycle.

[0127] Accurately weigh the dry weight of the regenerated magnetic seeds and record it as M1.

[0128] 4. Subsequent loops

[0129] Repeat steps 2 and 3 with the regenerated magnetic seed of mass M1 to perform the next adsorption-desorption cycle.

[0130] After each cycle, the dry weight of the regenerated magnetic seeds is accurately measured and recorded as M2, M3, ..., M n (n is the number of iterations, performed 5 times to evaluate long-term stability).

[0131] 5. Performance recovery rate verification

[0132] After each adsorption step in the cycle, the supernatant was collected, and the concentrations of residual heavy metal ions and microplastics were measured according to the methods in Experimental Example 1 and Experimental Example 2. The pollutant removal rate of this cycle was then calculated.

[0133] Data processing and computation:

[0134] Calculate the cumulative physical recovery rate after the nth cycle.

[0135]

[0136] The experimental results are shown in Table 1.

[0137] Table 1: Recovery rate of magnetic seeds

[0138]

[0139] This experiment, through precise quality tracking and performance testing, demonstrates that the physical recovery rate of the biomagnetic seed of this invention remains above 90% after five complete "adsorption-regeneration" cycles. Simultaneously, the performance recovery rates (adsorption efficiency retention rates) for heavy metals and microplastics are also above 90%. These results fully demonstrate that the biomagnetic seed of this invention possesses excellent structural stability, mechanical strength, and recyclability, providing crucial data support for its economic efficiency and reliability in practical engineering applications.

[0140] Experiment Example 2: Detection of Heavy Metal Ion Removal Efficiency

[0141] Experimental Objective: To quantitatively evaluate the adsorption capacity and removal rate of a one-step self-flocculation magnetic separation process for typical heavy metal ions.

[0142] Experimental methods:

[0143] For higher sensitivity, refer to the standard "Determination of Copper, Zinc, Lead and Cadmium in Water - Atomic Absorption Spectrophotometry" (GB 7475-87) or use inductively coupled plasma mass spectrometry (ICP-MS).

[0144] Simulated wastewater preparation: A background electrolyte solution (0.01 mol / L NaCl, pH = 7.0±0.1, pH stabilized using HEPES or PIPES buffer) was prepared using deionized water; lead nitrate (Pb(NO3)2) and cadmium nitrate (Cd(NO3)2) were added to the solution to stabilize the Pb content. 2+ and Cd 2+ The initial concentration of each was 10 mg / L.

[0145] Experimental group:

[0146] Take 250 mL of simulated wastewater into an Erlenmeyer flask, add the optimal dosage of biomagnetic seeds and the corresponding amount of superparamagnetic nanobubbles, and disperse them in two stages according to the treatment method of Example 1. The specific dispersion steps are as shown in Example 1.

[0147] Blank control group:

[0148] Take 250 mL of simulated wastewater, without adding any magnetic seeds, and oscillate synchronously to evaluate the adsorption on the container wall or experimental error.

[0149] Positive control group:

[0150] Take 250 mL of simulated wastewater, add an equal amount of unmodified magnetic particles, and oscillate synchronously for cross-sectional comparison.

[0151] Adsorption reaction:

[0152] Place all conical flasks in a constant-temperature shaker and shake at 150 rpm for 120 minutes at 25±1°C to ensure adsorption equilibrium is reached.

[0153] Magnetic separation:

[0154] After the reaction is complete, immediately place a strong magnet (≥1.0T) on the outside of the conical flask and let it adsorb for 2 minutes. Then, carefully aspirate the supernatant with a syringe.

[0155] Sample pretreatment:

[0156] Take 10 mL of the supernatant, filter it through a 0.45 μm aqueous microporous membrane, and immediately acidify it with nitric acid to pH < 2. Store it in a 4°C refrigerator until testing.

[0157] Detection and calculation:

[0158] Pb in the supernatants of the experimental group, blank control group, and positive control group was determined using atomic absorption spectrophotometry (AAS) or ICP-MS. 2+ and Cd 2+ concentration.

[0159] Removal rate calculation formula:

[0160]

[0161] The experimental results are shown in Table 2.

[0162] Table 2: Heavy Metal Ion Removal Efficiency

[0163]

[0164] Experiment Example 3: Microplastic Removal Efficiency Detection

[0165] Experimental objective: To quantitatively and qualitatively evaluate the capture efficiency and removal effect of the biomagnetic seeds and one-step process of this invention on hydrophobic microplastics.

[0166] Experimental methods:

[0167] Purchase polyethylene (PE) microspheres with a particle size range of 50-100 μm and disperse them in a background electrolyte solution (0.01 mol / L NaCl, pH = 7.0±0.1, using HEPES or PIPES buffer to maintain pH stability). Ensure that they do not agglomerate by ultrasonic dispersion (100W power, 5 min time). The initial concentration is set at 10 mg / L.

[0168] Experimental group setup: Same as Experiment Example 2

[0169] Adsorption reaction and magnetic separation: The steps are the same as in Experimental Example 2.

[0170] After the reaction was completed, the magnetic seeds were separated, and the supernatant was used to determine the concentration of residual microplastics.

[0171] The experimental results are shown in Table 3.

[0172] Table 3: Microplastic Removal Efficiency

[0173]

[0174] The above experiments demonstrate that this method has a good effect on wastewater treatment, with removal rates of heavy metal ions and microplastics both reaching over 90%.

[0175] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive control method for a magnetic flocculation reaction process, characterized in that, Includes the following steps: S1. Filter the wastewater, and then, based on the water quality data obtained from monitoring, add biomass magnetic seeds and superparamagnetic nanobubbles to the wastewater to obtain a mixed liquid. S2. The mixture is dispersed in two stages; S3. The products after the two-stage dispersion are magnetically separated to obtain treated wastewater and magnetic flocs. S4. Perform stepwise desorption on the magnetic flocs; The specific steps of the stepwise desorption in step S4 include: S401. Use a compound enzyme solution and stir at 40°C for 20 minutes. S402, then use 0.05 mol / L dilute nitric acid solution and stir for 10 min at room temperature; S403 was then washed five times alternately with deionized water and ethanol, and then vacuum dried at 40°C. The composite enzyme is a mixture of 0.5 wt% lipase and 0.5 wt% protease in a volume ratio of 1:

1. The method for preparing the superparamagnetic nanobubbles includes: A. Disperse Fe3O4 in PBS buffer containing 1 wt% phospholipids; B. Subsequently, under 400W power and ice bath conditions, inert protective gas was introduced into the solution, and ultrasonic treatment was carried out for 3-5 minutes.

2. The adaptive control method for the magnetic flocculation reaction process according to claim 1, characterized in that, The specific steps of the two-stage dispersion in step S2 include: S201. Disperse the mixture at 300±50 rpm for 2±0.5 min; S202, then dispersed at 50±20 rpm for 5±1 min.

3. The adaptive control method for the magnetic flocculation reaction process according to claim 1, characterized in that, The dosage of the biomass magnetic seed is 50 mg / L-150 mg / L; The amount of the superparamagnetic nanobubbles used is 50 mg / L-150 mg / L.

4. The adaptive control method for the magnetic flocculation reaction process according to claim 1, characterized in that, The biomass magnetic seed consists of an outermost shell, a middle layer, and a core. The core is a modified magnetic nanocluster; The intermediate layer is agricultural waste; The shell layer is a polylactic acid-polyethyleneimine copolymer; Of which, by weight percentage, the core content is 10%-25%; The middle layer accounts for 60%-80%; Shell layer 10%-20%.

5. The adaptive control method for the magnetic flocculation reaction process according to claim 1, characterized in that, The magnetic field strength for magnetic separation in step S3 is 0.8T-1.2T; the magnetic separation time is ≤ 1min.

6. The application of an adaptive control method for the magnetic flocculation reaction process as described in any one of claims 1-5 in wastewater treatment.

7. A system using the adaptive control method for the magnetic flocculation reaction process according to any one of claims 1-5.

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