CN-122010631-A - Method for preparing amino acid compound fertilizer by basic hydrolysis of excess sludge

CN122010631ACN 122010631 ACN122010631 ACN 122010631ACN-122010631-A

Abstract

The invention relates to the technical field of sludge treatment and resource utilization, in particular to a method for preparing an amino acid compound fertilizer by hydrolyzing excess sludge with alkali. The invention develops a low-cost residual sludge hydrolysis process by taking the waste residual sludge as a raw material, converts protein in the residual sludge into amino acid with high efficiency, so as to prepare the amino acid compound fertilizer applicable to crops, realize the reduction, harmlessness and recycling of the residual sludge, and produce the high-quality amino acid compound fertilizer, thereby solving the problems of high disposal cost, high environmental risk, expensive raw material production, serious resource consumption and the like of the existing residual sludge, and having remarkable economic and environmental benefits.

Inventors

HUI WENLONG
ZHANG LILI
FAN JINXIN
ZHAO YANAN
FENG SHUANG
ZHAO XIAOSHENG
WEI QIANG
DAI ZHIQIANG
ZHU LIN

Assignees

沧州师范学院

Dates

Publication Date: 20260512
Application Date: 20260309

Claims (10)

1. The method for preparing the amino acid compound fertilizer by basic hydrolysis of excess sludge is characterized by comprising the following steps of: S100 excess sludge pretreatment Heavy metal removal treatment is carried out on the residual sludge to obtain pretreated sludge; s200 basic hydrolysis treatment S201, carrying out hydrolysis reaction on the pretreated sludge and alkali liquor in the atmosphere of inert gas at the temperature of 80-120 ℃ and the reaction pressure of 0.1-0.3MPa under the condition of stirring; after the reaction of S202 is finished, the pH value of the reaction solution is regulated to 6.5-7.5, and then the reaction solution is filtered, and filtrate is taken; S300 amino acid compound fertilizer preparation And S301, adding the nutritional supplement into the filtrate, and uniformly mixing to obtain the liquid fertilizer.
2. The method for preparing amino acid compound fertilizer by basic hydrolysis of excess sludge according to claim 1, wherein the filtrate in step S301 is concentrated before adding the nutritional supplement, and the liquid fertilizer is granulated.
3. The method for preparing an amino acid compound fertilizer by basic hydrolysis of excess sludge according to claim 1, wherein in step S100, dehydration and crushing are sequentially performed before heavy metal removal treatment is performed on the excess sludge, specifically: Firstly, dehydrating the residual sludge, controlling the water content to be 60% -70%, and then crushing the residual sludge to the particle size of 1-3mm.
4. The method for preparing the amino acid compound fertilizer by basic hydrolysis of excess sludge according to claim 1, wherein the operation of removing heavy metals is performed on the excess sludge in step S100, specifically: Mixing the residual sludge with a chelating agent solution, and carrying out chelation reaction under the stirring condition at the temperature of 25-35 ℃; After the chelation reaction is combined, centrifugally separating, and collecting sediment, namely the pretreated sludge.
5. The method for preparing the amino acid compound fertilizer by basic hydrolysis of excess sludge, which is characterized in that the chelating agent solution is disodium ethylenediamine tetraacetate aqueous solution with the concentration of 0.05-0.1mol/L, and the mass ratio of the excess sludge to the chelating agent solution is 1 (3-5).
6. The method for preparing the amino acid compound fertilizer by basic hydrolysis of excess sludge according to claim 1, wherein the alkaline solution in the step S201 is selected from sodium hydroxide aqueous solution or potassium hydroxide aqueous solution with the mass concentration of 10% -20%; the mass of the pretreated sludge and the alkali liquor is 1 (2-4).
7. The method for preparing an amino acid compound fertilizer by basic hydrolysis of excess sludge according to claim 1, wherein the nutritional supplement of step S301 consists of urea, potassium dihydrogen phosphate and potassium sulfate in a mass ratio of 2:1:1.
8. An amino acid compound fertilizer prepared by the method for preparing the amino acid compound fertilizer by hydrolyzing residual sludge with alkali according to any one of claims 1 to 7.
9. The use of the amino acid compound fertilizer of claim 8 as a foliar fertilizer, or a root flush fertilizer, or a soilless nutrient solution in crop planting.
10. The use according to claim 9, wherein the crop comprises at least one of rice, wheat, corn, soybean, peanut, cucumber, and pepper.

Description

Method for preparing amino acid compound fertilizer by basic hydrolysis of excess sludge Technical Field The invention relates to the technical field of sludge treatment and resource utilization, in particular to a method for preparing an amino acid compound fertilizer by hydrolyzing excess sludge with alkali. Background Along with the acceleration of the urban process, the sewage treatment capacity is increased year by year, and the quantity of the generated surplus sludge is also increased sharply. The residual sludge has complex components and contains a large amount of organic matters, heavy metals, pathogens and the like, and if the residual sludge is improperly treated, serious environmental problems such as soil pollution, groundwater pollution and the like can be caused. At present, the treatment modes of the excess sludge mainly comprise landfill, incineration, composting and the like. The landfill treatment has large occupied area, is easy to produce percolate to pollute underground water, has high energy consumption in incineration treatment and can produce toxic and harmful gases such as dioxin, the traditional composting treatment has long period, large occupied area and lower fertilizer efficiency of products, and the requirements of modern agriculture on high-quality fertilizers are difficult to meet. Meanwhile, the demand for amino acid compound fertilizers in agricultural production is growing. The amino acid compound fertilizer can provide rich amino acid nutrition for crops, promote the growth of the crops and improve the yield and quality of the crops. The existing amino acid compound fertilizer is prepared by taking grains, bean pulp and the like as raw materials, has high cost and consumes a large amount of grain resources. Therefore, finding a preparation raw material and a method of an amino acid compound fertilizer with low cost becomes a current problem to be solved urgently. The residual sludge contains a large amount of protein, and the protein can generate amino acid through hydrolysis, so that potential raw materials are provided for preparing the amino acid compound fertilizer. The existing sludge hydrolysis method mainly comprises acid hydrolysis, enzyme hydrolysis and the like. Although the acid hydrolysis method has higher hydrolysis efficiency, the acid hydrolysis method can corrode equipment, a large amount of salt substances can be generated in the subsequent neutralization process to influence the quality of the fertilizer, and the enzyme hydrolysis method has mild reaction conditions, but the enzyme preparation has high cost and long hydrolysis period, so that the industrial mass production is difficult to realize. Based on the method, an efficient, low-cost and environment-friendly excess sludge hydrolysis process is developed, is used for preparing the amino acid compound fertilizer, and has important practical significance and application value. Disclosure of Invention Therefore, based on the background, the invention provides a method for preparing the amino acid compound fertilizer by basic hydrolysis of residual sludge, which takes waste residual sludge as a raw material, develops a low-cost residual sludge hydrolysis process, converts protein in the residual sludge into amino acid with high efficiency to prepare the amino acid compound fertilizer applicable to crops, realizes the reduction, harmlessness and recycling of the residual sludge, and produces the high-quality amino acid compound fertilizer, thereby solving the problems of high treatment cost, high environmental risk, expensive raw material for producing the amino acid fertilizer, serious resource consumption and the like of the existing residual sludge, and having remarkable economic and environmental benefits. The technical scheme provided by the invention is as follows: a method for preparing an amino acid compound fertilizer by basic hydrolysis of excess sludge comprises the following steps: S100 excess sludge pretreatment Heavy metal removal treatment is carried out on the residual sludge to obtain pretreated sludge; s200 basic hydrolysis treatment S201, carrying out hydrolysis reaction on the pretreated sludge and alkali liquor in the atmosphere of inert gas at the temperature of 80-120 ℃ and the reaction pressure of 0.1-0.3MPa under the condition of stirring; after the reaction of S202 is finished, the pH value of the reaction solution is regulated to 6.5-7.5, and then the reaction solution is filtered, and filtrate is taken; S300 amino acid compound fertilizer preparation And S301, adding the nutritional supplement into the filtrate, and uniformly mixing to obtain the liquid fertilizer. Further, the filtrate in the step S301 is concentrated before the nutritional supplement is added, and the liquid fertilizer is granulated. Further, in step S100, dehydration and crushing are sequentially performed before heavy metal removal treatment is performed on the surplus sludge, specifically: Firstly, de