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CN-121974374-A - Resource utilization method of compost leachate

CN121974374ACN 121974374 ACN121974374 ACN 121974374ACN-121974374-A

Abstract

The invention belongs to the technical field of organic fertilizers, discloses a resource utilization method of compost leachate, and solves the technical problem that nitrogen in the compost leachate is not fully utilized in the prior art. The resource utilization method of the compost percolate comprises the following steps of adding organic nitrogen mineralization promoting composite bacteria into the compost percolate to perform aerobic reaction to decompose the organic nitrogen to obtain an aerobic reaction liquid, adding anaerobic myxobacteria into the aerobic reaction liquid to perform anaerobic reaction to convert nitrate nitrogen into ammonium nitrogen to obtain an anaerobic reaction liquid, adding citric acid-ferrous modified biochar into the anaerobic reaction liquid to adsorb the ammonium nitrogen, filtering to obtain ammonium nitrogen loaded biochar, desorbing the ammonium nitrogen loaded biochar by using NaCl solution, collecting release liquid and desorbing the charcoal, and concentrating and crystallizing the release liquid to obtain ammonium chloride crystals.

Inventors

  • HUANG KUNMING
  • TIAN XIAOSU
  • LI JIANGRONG
  • LI XIN

Assignees

  • 成都达奇科技股份有限公司

Dates

Publication Date
20260505
Application Date
20251212

Claims (10)

  1. 1. The resource utilization method of the compost leachate is characterized by comprising the following steps: step A, adding organic nitrogen mineralization promoting composite bacteria into the compost percolate to perform an aerobic reaction so as to decompose the organic nitrogen, thereby obtaining an aerobic reaction liquid; step B, anaerobic myxobacteria are added into the aerobic reaction liquid to perform anaerobic reaction so as to convert nitrate nitrogen into ammonium nitrogen, and an anaerobic reaction liquid is obtained; Step C, adding citric acid-ferrous modified biochar into the anaerobic reaction liquid to adsorb ammonium nitrogen, and filtering to obtain ammonium nitrogen loaded biochar; Step D, desorbing the ammonium nitrogen loaded biochar by using NaCl solution, and collecting the released liquid and desorbing the biochar; And E, concentrating and crystallizing the release liquid to obtain ammonium chloride crystals.
  2. 2. The method for utilizing resources according to claim 1, wherein in step A: The organic nitrogen mineralization promoting composite bacteria are formed by mixing streptomycete and candida tropicalis according to the volume ratio of 1:1; The aerobic reaction condition is that the adding amount of the organic nitrogen mineralization promoting composite bacteria is 1-3 vol%, the pH is 7.0-7.5, the reaction temperature is 45-50 ℃, and the reaction time is 8-10.
  3. 3. The method for utilizing resources according to claim 1, wherein in the step B, anaerobic reaction conditions are that the addition amount of the anaerobic myxobacteria is 1-2 vol%, the pH is 5.0-6.5, and the reaction is carried out in a sealed manner at 25-30 ℃ for 6-8 hours.
  4. 4. The method of claim 1, wherein the concentration of ammonium nitrogen in the anaerobic reaction liquid entering the step C is controlled to be 400-500 mg/L by heating and concentrating in water bath or diluting in distilled water after the reaction in the step B is finished.
  5. 5. The method for utilizing resources according to claim 4, wherein in the step C, the adsorption condition is that the adding amount of the citric acid-ferrous modified biochar is 50-60 g/L, the pH is 7.0-7.5, the stirring speed is 130-170 rpm, the adsorption is carried out at normal temperature for 45-60 minutes, and the filtration is carried out by using a 0.45-micrometer filter membrane after the adsorption is finished.
  6. 6. The method for utilizing resources according to claim 1, wherein in the step C, the preparation of the citric acid-ferrous modified biochar comprises the steps of immersing the biochar in a citric acid-ferrous solution, carrying out hydrothermal reaction for 2-6 hours at 150-170 ℃, collecting solids after the reaction is finished, and washing and drying to obtain the citric acid-ferrous modified biochar, wherein the biochar is bamboo biochar formed by carbonizing fresh bamboo, the granularity is 10-30 meshes, and the specific surface area is more than or equal to 200m 2 /g.
  7. 7. The resource utilization method according to claim 6, wherein deionized water is added according to a solid-to-liquid ratio of 1.8-2.0 g/mL to melt citric acid and ferrous sulfate, pH is adjusted to 3.0-4.0 by 1mol/L NaOH to obtain a citric acid-ferrous solution, a molar ratio of Fe 2+ to citric acid in the citric acid-ferrous solution is 1 (1.5-2.5), and a liquid-solid ratio of the citric acid-ferrous solution to biochar is 6-10 mL/g.
  8. 8. The method of claim 6, wherein the desorption carbon is washed with 5 wt.% HCl for 1 to 1.5 hours, rinsed with deionized water to neutrality, and dried and recycled for adsorption recovery in step C.
  9. 9. The method for utilizing resources according to claim 1, wherein in the step D, the desorption condition is that the concentration of NaCl solution is 0.8-1.2 mol/L, the liquid-solid ratio of NaCl solution to ammonium nitrogen loaded biochar is 4-6 mL/g, the pH is 8.0-9.0, the desorption is carried out for 30-45 minutes under normal temperature stirring, and after the desorption is finished, the solution is filtered by a 0.45 micrometer filter membrane.
  10. 10. The resource utilization method according to claim 1, wherein in the step E, the concentration treatment is heating to 45-60 ℃ in water bath for concentration until the concentration of ammonium nitrogen is more than or equal to 10g/L, the crystallization treatment is adding ammonium chloride with the purity of more than or equal to 99.8% as an induction crystal, and the ammonium chloride crystal is refrigerated and separated out in an environment of 0 ℃.

Description

Resource utilization method of compost leachate Technical Field The invention relates to the technical field of organic fertilizers, in particular to a resource utilization method of compost leachate. Background The continuous increase of the yield of grains, oil and forest products is accompanied with the great increase of agricultural and forestry wastes, and the recycling problem of the agricultural and forestry wastes is increasingly outstanding. At present, the main utilization modes of the agricultural and forestry wastes comprise biomass power generation, straw returning, forage conversion, base material conversion, fuel conversion, industrial raw material utilization and the like. The base material of the agriculture and forestry waste is mainly utilized to prepare the organic fertilizer through composting fermentation. In the composting process, nitrogen loss is a key problem affecting the quality and nutrient utilization rate of the compost, and the main loss modes comprise ammonia volatilization, nitrification-denitrification, leaching loss, microbial immobilization conversion and the like. Although the prior art attempts to introduce passivating agents, biological inhibitors and microbial agents to control nitrogen loss, the control effect is poor. Besides nitrogen loss, the existing technology still has obvious short plates in the aspect of nitrogen regulation, on one hand, the nitrogen holding effect of the finished compost product is poor, the fertilizer efficiency is difficult to ensure, and on the other hand, the nitrogen in the compost leachate is not fully utilized. Disclosure of Invention The first aim of the invention is to provide a composition for preparing decomposed compost, a preparation method of the decomposed compost, a composition for preparing biochar-based organic fertilizer and a preparation method of the biochar-based organic fertilizer, so as to solve the technical problems of high nitrogen loss and poor nitrogen retaining effect of a finished compost product in the prior art. The composition for preparing the decomposed compost comprises a high-carbon-nitrogen-ratio biomass raw material, a low-carbon-nitrogen-ratio biomass raw material, exogenous nitrogen, citric acid-ferrous modified biochar and a composite microbial inoculum, wherein the C/N ratio of the high-carbon-nitrogen-ratio biomass raw material is 60-80, the C/N ratio of the low-carbon-nitrogen-ratio biomass raw material is 15-20, and the composite microbial inoculum A comprises organic nitrogen mineralization promoting bacteria, TNRA functional bacteria and nitrification-denitrification inhibiting bacteria. As a further improvement of the composition, the mass ratio of the biomass raw material with high carbon-nitrogen ratio to the biomass raw material with low carbon-nitrogen ratio to the exogenous nitrogen to the modified biochar to the composite microbial inoculum is (55-65)/(25-35)/(2-4)/(8-12)/(1-3). The composition is further improved in that the high-carbon-nitrogen-ratio biomass raw material is at least one selected from crop straws, garden waste and agricultural product processing residues, the low-carbon-nitrogen-ratio biomass raw material is at least one selected from kitchen waste, fruit and vegetable residues, soybean meal, peanut meal, rapeseed meal and algae biological residues, the exogenous nitrogen is at least one selected from urea, ammonium chloride, ammonium sulfate and sodium nitrate, and the composite microbial inoculum A comprises bacillus subtilis, bacillus megaterium, streptomycete, trichoderma, anaerobic myxobacteria and aspergillus niger. As a further improvement of the composition, the composite microbial inoculum is prepared by mixing bacillus subtilis, bacillus megatherium, streptomycete, trichoderma, anaerobic myxobacteria and aspergillus niger according to the volume ratio of 2:2:1:2:1:2. The preparation method of the citric acid-ferrous modified biochar comprises the steps of immersing the biochar in a citric acid-ferrous solution, carrying out hydrothermal reaction at 150-170 ℃ for 2-6 hours, collecting solids after the reaction is finished, and washing and drying to obtain the citric acid-ferrous modified biochar, wherein the biochar is bamboo biochar formed by carbonizing fresh bamboo, the granularity is 10-30 meshes, and the specific surface area is more than or equal to 200m 2/g. The preparation method of the decomposed compost comprises the steps of piling the composition and performing aerobic fermentation to obtain the decomposed compost. The preparation method is further improved in that the height of a pile body is 1.2-1.5 m, the width of the pile body is 2-3 m, the length of the pile body is 2.5-3.5 m, the aerobic fermentation process comprises a heating period, a high-temperature period and a post-maturation period which are sequentially carried out, the heating period is that the reaction temperature is raised to be more than 50 ℃ in the first 3 days, the high-tempe