Search

CN-121226077-B - Method for preparing water-soluble organic fertilizer by fermenting supernatant by methane-oxidizing bacteria

CN121226077BCN 121226077 BCN121226077 BCN 121226077BCN-121226077-B

Abstract

The invention provides a method for preparing a water-soluble organic fertilizer by utilizing methane-oxidizing bacteria fermentation supernatant, which comprises the steps of S1, constructing a methane-oxidizing bacteria aerobic fermentation system, regulating and controlling the methane-oxidizing bacteria aerobic fermentation system in real time through an LSTM neural network and a genetic algorithm, separating the methane-oxidizing bacteria fermentation supernatant after fermentation is finished, S2, collecting process wastewater generated in the fermentation process, regulating the process wastewater by adopting a BP neural network and a fuzzy PID controller to obtain wastewater treatment effluent, S3, mixing the fermentation supernatant and the wastewater treatment effluent in proportion, adding humic acid liquid, urea and monopotassium phosphate as supplements, and optimizing the mixing proportion and the adding amount of the supplements through an NSGA-II algorithm to obtain the water-soluble organic fertilizer. The whole process realizes intelligent regulation and control through data closed-loop feedback, not only improves the recycling level of fermentation products and wastewater, but also ensures the quality and economy of organic fertilizer, and forms an integrated intelligent production system of microbial fermentation-wastewater treatment-fertilizer preparation.

Inventors

  • CHEN YUTONG
  • CHEN Jin
  • LI XINQI

Assignees

  • 北京德量源生物科技有限公司

Dates

Publication Date
20260508
Application Date
20251014

Claims (9)

  1. 1. The method for preparing the water-soluble organic fertilizer by fermenting the supernatant by using methane-oxidizing bacteria is characterized by comprising the following steps: S1, constructing a methane-oxidizing bacteria aerobic fermentation system, predicting the concentration of thalli and the organic matter content of supernatant fluid in the fermentation process through an LSTM neural network, optimizing the super-parameters of LSTM by combining a genetic algorithm, regulating and controlling the fermentation temperature, the stirring rotating speed and the CH 4 /O 2 ventilation ratio in real time, and separating after the fermentation is finished to obtain fermentation supernatant fluid; S2, collecting process wastewater generated in the fermentation process, optimizing coagulant addition amount by adopting a BP neural network after homogenization treatment, and adjusting dissolved oxygen and residence time in a biological treatment stage by a fuzzy PID controller to obtain wastewater treatment effluent; S3, mixing the fermentation supernatant in the step S1 with the wastewater treatment effluent in the step S2 in proportion, adding humic acid liquid, urea and monopotassium phosphate as supplements, optimizing the mixing proportion and the additive amount of the supplements through an NSGA-II algorithm, homogenizing, sterilizing and filtering to obtain the water-soluble organic fertilizer; The optimization result of the NSGA-II algorithm in the step S3 is fed back to the step S1, the weight of the organic matter prediction in the LSTM neural network is adjusted to form closed-loop regulation, and the specific process of the closed-loop regulation is that when the volume ratio of the fermentation supernatant output by the NSGA-II algorithm to the wastewater treatment effluent is greater than the historical average value, the weight of the organic matter prediction in the LSTM neural network is improved, so that the organic matter content of the fermentation supernatant is preferentially improved when the genetic algorithm is optimized.
  2. 2. The method for preparing a water-soluble organic fertilizer by fermenting supernatant with methane-oxidizing bacteria according to claim 1, wherein in the step S1, input parameters of the LSTM neural network include fermentation temperature, stirring rotation speed, CH 4 /O 2 ventilation ratio, fermentation liquor pH value and dissolved oxygen concentration, output parameters are thallus concentration and supernatant organic matter content for 4 hours in the future, and a genetic algorithm optimizes learning rate of the LSTM and hidden layer node number by minimizing prediction errors.
  3. 3. The method for preparing the water-soluble organic fertilizer by utilizing the methane-oxidizing bacteria fermentation supernatant according to claim 1, wherein in the step S1, the triggering condition of real-time regulation is that when the speed increase of the LSTM predicted supernatant organic matter is lower than 1%. H -1 , the CH 4 /O 2 ventilation ratio and the stirring rotating speed are adjusted according to the speed increase difference value, and the adjustment coefficient is obtained by fitting historical data through a genetic algorithm.
  4. 4. The method for preparing the water-soluble organic fertilizer by utilizing the methane-oxidizing bacteria fermentation supernatant according to claim 1, wherein in the step S2, the input of the BP neural network is the COD value of the homogenized wastewater, the output is the optimal addition amount of the coagulant PAC, and model training is performed by minimizing the deviation between the COD value of the coagulated wastewater and a target value, so that the COD after coagulation is ensured to be less than or equal to 300mg/L.
  5. 5. The method for preparing the water-soluble organic fertilizer by utilizing the methane-oxidizing bacteria fermentation supernatant fluid according to claim 1, wherein in the step S2, the COD value and the ammonia nitrogen value of the inlet of the biological treatment tank are input into a fuzzy PID controller, the set value of dissolved oxygen and the retention time are determined through a preset fuzzy rule table, and then the opening of an aeration valve and the flow rate of a water outlet valve are regulated through a PID algorithm, so that the COD of the treated wastewater is less than or equal to 100mg/L and the ammonia nitrogen is less than or equal to 15mg/L.
  6. 6. The method for preparing a water-soluble organic fertilizer by using methane-oxidizing bacteria fermentation supernatant according to claim 1, wherein in the step S3, the optimization objective of the NSGA-II algorithm includes maximizing the organic matter content of the mixed liquor, maximizing the total n+p 2 O 5 +K 2 O content, minimizing the pH deviation and minimizing the cost, provided that the heavy metal content in the mixed liquor meets the water-soluble organic fertilizer standard.
  7. 7. The method for preparing the water-soluble organic fertilizer by utilizing the methane-oxidizing bacteria fermentation supernatant according to claim 1, wherein in the step S3, the source of the supplement is that humic acid liquid is prepared by extracting weathered coal, urea is agricultural grade granular urea, monopotassium phosphate is industrial grade crystal, and the purity of the three is more than or equal to 98 percent.
  8. 8. The method for preparing a water-soluble organic fertilizer by using methane-oxidizing bacteria fermentation supernatant according to claim 1, wherein in the step S1, a culture medium of a fermentation system comprises NH 4 NO 3 、MgSO 4 ·7H 2 O、KH 2 PO 4 and FeSO 4 ·7H 2 O, the pH is adjusted to 6.5-7.5, the fermentation temperature is controlled to 28-32 ℃, and the period is 5-7 days.
  9. 9. The method for preparing a water-soluble organic fertilizer by using methane-oxidizing bacteria fermentation supernatant according to claim 1, wherein in the step S3, a high-pressure homogenizer is used for homogenization treatment, the working pressure is 20-30 MPa, the sterilization mode is pasteurization, the condition is that the temperature is 70 ℃ and the temperature is kept for 20 minutes, and a 5- μm filter membrane is used for filtration.

Description

Method for preparing water-soluble organic fertilizer by fermenting supernatant by methane-oxidizing bacteria Technical Field The invention relates to the technical field of intersection of agricultural biotechnology and environmental engineering, in particular to a method for preparing a water-soluble organic fertilizer by fermenting supernatant liquid by using methane-oxidizing bacteria. Background The water-soluble organic fertilizer is widely applied in modern agriculture due to the characteristics of easy absorption by crops, environmental friendliness and the like. The traditional preparation method relies on animal and plant waste decomposition or chemical synthesis, and has the problems of unstable raw material sources, low nutrient content, large pollution in the production process and the like. The methane-oxidizing bacteria fermentation supernatant is rich in natural organic matters such as organic acid, amino acid and the like, is a high-quality raw material for preparing the organic fertilizer, but is utilized at present to stay at a direct dilution use stage, is not used in a cooperative and resource way with process wastewater, and the fermentation process parameter regulation and control depend on experience, so that the quality fluctuation of the supernatant is large. Meanwhile, the waste water (such as flushing water and condensed water) generated in the fermentation and preparation processes contains a small amount of available nutrients, and the traditional treatment mode only focuses on standard emission, ignores resource recovery and causes waste. In addition, the formula of the organic fertilizer is determined by manual trial and error, so that the fertility, the cost and the stability are difficult to balance, and an intelligent optimization means is lacked. Therefore, a technology for preparing the water-soluble organic fertilizer, which can efficiently utilize methane-oxidizing bacteria fermentation supernatant and cooperatively treat wastewater and optimize the whole process through an intelligent algorithm, is needed to improve the resource utilization rate and the product quality. Disclosure of Invention The invention provides a method for preparing a water-soluble organic fertilizer by utilizing methane-oxidizing bacteria fermentation supernatant, which takes the methane-oxidizing bacteria fermentation supernatant as a core raw material, combines the processed process wastewater, and prepares the water-soluble organic fertilizer through multi-algorithm collaborative optimization. The specific flow comprises the following steps: optimizing methane-oxidizing bacteria fermentation parameters by utilizing an LSTM-genetic algorithm, and stabilizing the organic matter and nutrient content in fermentation supernatant; adopting BP neural network and fuzzy PID to cooperatively treat the process wastewater, and reserving auxiliary nutrients on the basis of reaching standards to obtain qualified effluent; optimizing the proportion of supernatant, wastewater effluent and supplements (humic acid, urea and the like) by using an NSGA-II multi-objective algorithm, and balancing fertility, cost and stability; Refining by mixing, homogenizing, sterilizing and other processes to finally obtain the high-quality water-soluble organic fertilizer. The whole process realizes intelligent regulation and control through data closed-loop feedback, not only improves the recycling level of fermentation products and wastewater, but also ensures the quality and economical efficiency of organic fertilizer, and forms an integrated intelligent production system of microbial fermentation, wastewater treatment and fertilizer preparation. In order to achieve the above purpose, the invention adopts the following technical scheme: the method for preparing the water-soluble organic fertilizer by fermenting the supernatant by using methane-oxidizing bacteria comprises the following steps: S1, constructing a methane-oxidizing bacteria aerobic fermentation system, predicting the concentration of thalli and the organic matter content of supernatant fluid in the fermentation process through an LSTM neural network, optimizing the super-parameters of LSTM by combining a genetic algorithm, regulating and controlling the fermentation temperature, the stirring rotating speed and the CH 4/O2 ventilation ratio in real time, and separating after the fermentation is finished to obtain fermentation supernatant fluid; S2, collecting process wastewater generated in the fermentation process, optimizing coagulant addition amount by adopting a BP neural network after homogenization treatment, and adjusting dissolved oxygen and residence time in a biological treatment stage by a fuzzy PID controller to obtain wastewater treatment effluent; S3, mixing the fermentation supernatant in the step S1 with the wastewater treatment effluent in the step S2 in proportion, adding humic acid liquid, urea and monopotassium phosphate as supplements, opt