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CN-122010608-A - Catechol-manganese dioxide synergistic directional humification pig manure aerobic composting nitrogen-preserving method

CN122010608ACN 122010608 ACN122010608 ACN 122010608ACN-122010608-A

Abstract

The invention discloses a nitrogen-preserving method for pig manure aerobic composting by catechol-manganese dioxide synergistic directional humification. The preparation method comprises the steps of taking sawdust, straw or rice husk as a carbon-rich loosening agent, preferably carrying out mild oxidation and anchoring a modified carrier of gamma-MnO 2 , adding catechol in a mixing stage, adding active MnO 2 in stages in the initial stage of composting, and promoting the oxidative condensation of catechol and nitrogen-containing organic matters in a weak acid to neutral and moderately ventilated initial reaction window, and then curing to a maturity criterion. The method suppresses ammoniation and dissipation from the source, improves the fixation and humification degree of nitrogen in an organic combination state, reduces peculiar smell, improves the stability and uniformity of finished products, and is suitable for recycling treatment of livestock and poultry manure.

Inventors

  • HUANG LEI
  • YANG ZHIMIN
  • XIAO GUANGQUAN
  • CHEN YUCHENG
  • Chang Qixiang
  • YANG AN
  • YIN JIAO
  • LI CHENXI
  • Su Tianye
  • ZHOU GUOHONG
  • CHEN WEIHONG
  • ZHENG WEI

Assignees

  • 西南大学

Dates

Publication Date
20260512
Application Date
20251127

Claims (10)

  1. 1. A catechol-manganese dioxide synergistic directional humification pig manure aerobic composting nitrogen-preserving method is characterized by comprising the following steps: S1, raw material preparation, namely mixing pig manure with a carbon-rich loosening agent, wherein the carbon-rich loosening agent is selected from one or more of sawdust, straw or rice hulls, adjusting the water content to 60-65%, mixing the water with water according to the mass ratio of 1:10 to prepare suspension, and measuring the initial pH value to be 6.6-7.2; s2, adding 0.1-0.3wt% of catechol according to the dry matter of the materials, and adding and uniformly mixing at one time in a mixing stage; s3, manganese dioxide is added in sections, namely 0.05-0.2wt% of active manganese dioxide powder is added according to the dry matter of the materials, and 50-60% and 40-50% of the total manganese dioxide are respectively added in two periods of 0-24 h and 24-72 h; s4, an initial reaction window, namely adopting continuous aeration or intermittent aeration with the duty ratio being more than or equal to 50% in 0-72 h, wherein the ventilation is 0.15-0.25 L.min -1 ·kg -1 (calculated by volatile solids), and the pH value of the stack is maintained to be 6.6-7.2 through an acid regulator; and S5, carrying out subsequent curing, namely continuing aerobic composting after finishing the initial window until at least any two of the following two conditions are met, wherein the germination index GI is more than or equal to 80%, the stacking temperature is stable and is less than or equal to 40 ℃ and is continuous for 48 hours, or the finished product C/N is less than or equal to 20.
  2. 2. The method for preserving nitrogen by utilizing pig manure aerobic composting through synergistic orientation humification of catechol and manganese dioxide according to claim 1, wherein the acidity regulator is one of phosphoric acid, citric acid or a mixture thereof.
  3. 3. The catechol-manganese dioxide synergistic directional humified pig manure aerobic composting nitrogen-preserving method of claim 1, wherein the dry basis mass of the carbon-rich bulking agent accounts for 10-40% of the total dry mass of pig manure and the carbon-rich bulking agent, and the particle size of the carbon-rich bulking agent is 5-30 mm.
  4. 4. The method for preserving nitrogen by aerobic composting of pig manure by synergistic directional humification of catechol-manganese dioxide according to claim 3, wherein one or more of saw dust, straw or rice husk is oxidized for 30-120 min at 40-60 ℃ with 0.5-2.0wt% hydrogen peroxide aqueous solution, the surface of the treated material is washed and dried, the total phenol content of the treated material is more than or equal to 0.50 mmol.g -1 based on catechol equivalent, and gamma-MnO 2 is anchored on the fiber hole wall in a dipping in-situ deposition mode, wherein the load is 0.10-0.50wt%.
  5. 5. The method for preserving nitrogen by utilizing the pig manure aerobic composting through the synergistic directional humification of catechol and manganese dioxide, which is disclosed in claim 1, is characterized in that the duty ratio of intermittent aeration is 60-80%, and the single period is 10-30 min. .
  6. 6. The method for preserving nitrogen by utilizing pig manure aerobic composting through synergistic directional humification of catechol and manganese dioxide according to claim 1, wherein d 50 of particle volume distribution of the active manganese dioxide is 50-200 nm.
  7. 7. The method for preserving nitrogen by aerobic composting of pig manure by synergistic directional humification of catechol and manganese dioxide according to claim 6, wherein the BET relative specific surface area of the active manganese dioxide is 80-150 m 2 ·g -1 .
  8. 8. The method for preserving nitrogen by utilizing pig manure aerobic composting through synergistic orientation humification of catechol and manganese dioxide according to claim 7, wherein the oxygen vacancy peak area ratio in O1s peak separation measured by XPS of the active manganese dioxide is 20-30%.
  9. 9. The method for preserving nitrogen by aerobic composting of pig manure by synergistic directional humification of catechol and manganese dioxide according to claim 8, wherein the atomic ratio of Mn 3+ /Mn 4+ in the active manganese dioxide is 0.35-0.70.
  10. 10. The method for preserving nitrogen by utilizing pig manure aerobic composting through synergistic directional humification of catechol and manganese dioxide according to claim 1, wherein the active manganese dioxide is ternary doping of Bi-Co-Cu, and the total doping amount is 0.2-1.5 at%.

Description

Catechol-manganese dioxide synergistic directional humification pig manure aerobic composting nitrogen-preserving method Technical Field The invention relates to the technical field of composting, in particular to a catechol-manganese dioxide synergistic directional humification pig manure aerobic composting nitrogen-preserving method. Background The livestock manure aerobic composting is used as a key technical means for recycling agricultural solid wastes, and the composting process, especially the nitrogen loss phenomenon commonly existing in the heating period and the high temperature period and the odor emission problem generated in the heating period are increasingly concerned while recycling organic matters. Intensive researches show that the intrinsic mechanism of the problem is mainly characterized in that firstly, in a high-temperature environment, protein and amino acid substances can undergo rapid ammoniation reaction to directly cause the volatility loss of ammonia, secondly, nitrogen can be lost through various gaseous forms (such as N 2 O, NO and the like) in the processes of nitrification and denitrification participated by microorganisms, and furthermore, water-soluble organic matters generated in the early stage of composting are mostly contained in components with smaller molecular weight, and the substances are difficult to be converted into macromolecular humus precursor substances with more stable structures through complex biochemical processes in a short time, so that the nitrogen cannot be effectively fixed in chemical combination structures which are difficult to volatilize and migrate. Aiming at the problem of nitrogen loss, the solution commonly adopted in the industry at present mainly focuses on the middle and later treatment stages of composting. The specific measures include reducing the volatility of ammonia gas by acidification treatment, improving the fixation efficiency of ammonium nitrogen by utilizing adsorption materials (such as biochar, zeolite and other porous minerals) or by forming mineralized products (such as adding magnesium salt-phosphate to form insoluble magnesium ammonium phosphate precipitate), or inhibiting the occurrence of ammoniation reaction by precisely regulating key operation parameters such as ventilation, moisture content, pH value and the like. However, these conventional methods have many limitations in that the mechanism of action is to perform passive interception after nitrogen has been converted into a volatile or easily-migrating form, and the method is very strict in terms of operation time window, is easy to inhibit microbial activity, and shows strong sensitivity to raw material characteristics and batch differences, and more importantly, the methods have limited contribution to improving humification degree of the final product. In recent years, research on promotion of humification process by redox medium has been developed, but the prior research has been focused on the field of broad-spectrum oxidation or pollutant degradation, and the related research on early stage of composting, especially in weak acid to neutral environment, is still insufficient. Under the background, how to guide nitrogen into a stable combined state conversion path which is difficult to volatilize and decompose at the initial stage of composting by a technical means, and effectively control the emission of peculiar smell and ensure the stable quality of a final product at the same time becomes a key problem to be solved urgently. Disclosure of Invention The invention aims to overcome the problems in the prior art and provide a method for preserving nitrogen in pig manure aerobic composting by using catechol-manganese dioxide synergistic directional humification. In order to achieve the aim, the first aspect of the invention provides a catechol-manganese dioxide synergistic directional humification pig manure aerobic composting nitrogen-preserving method, which comprises the following steps: S1, raw material preparation, namely mixing pig manure with a carbon-rich loosening agent, wherein the carbon-rich loosening agent is selected from one or more of sawdust, straw or rice hulls, adjusting the water content to 60-65%, mixing the water with water according to the mass ratio of 1:10 to prepare suspension, and measuring the initial pH value to be 6.6-7.2; s2, adding 0.1-0.3wt% of catechol according to the dry matter of the materials, and adding and uniformly mixing at one time in a mixing stage; s3, manganese dioxide is added in sections, namely 0.05-0.2wt% of active manganese dioxide powder is added according to the dry matter of the materials, and 50-60% and 40-50% of the total manganese dioxide are respectively added in two periods of 0-24 h and 24-72 h; s4, an initial reaction window, namely adopting continuous aeration or intermittent aeration with the duty ratio being more than or equal to 50% in 0-72 h, wherein the ventilation is 0.15-0.25 L.min -1·kg-1 (