Method for preparing phosphate fertilizer from municipal sludge

A municipal sludge and phosphate fertilizer technology, applied in the field of solid waste recycling, can solve the problems of low phosphorus extraction efficiency and high risk of heavy metal environmental pollution, etc., and achieve good practical results

Pending Publication Date: 2020-07-24
INST OF ROCK & SOIL MECHANICS CHINESE ACAD OF SCI
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and to provide a method for preparing phosphate fertilizer from municipal sludge that can effectively solve the problems of low phosphorus extraction efficiency and high environmental pollution risk of leached heavy metals in the existing sludge phosphorus extraction method. Methods

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  • Method for preparing phosphate fertilizer from municipal sludge
  • Method for preparing phosphate fertilizer from municipal sludge
  • Method for preparing phosphate fertilizer from municipal sludge

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Embodiment 1

[0033] figure 1 It is the method flowchart of the method for preparing phosphate fertilizer with municipal sludge of the present invention, as figure 1 As shown, the present embodiment provides a method for preparing phosphate fertilizer from municipal sludge, comprising the following steps:

[0034] S01. Incinerate municipal sludge to obtain incineration ash.

[0035] In step S01 of this embodiment, since the municipal sludge contains abundant organic residues, and phosphorus element is also in these organic substances, the first thing to be removed is the organic substances in the municipal sludge, and most of the organic substances are combustible substances. Therefore, toxic and harmful organic residues in municipal sludge can be removed by incineration. These organic residues are thermally oxidized and decomposed during the combustion process, and finally the remaining incineration ash is inorganic residues, and the form of phosphorus is also From organic phosphorus to ...

Embodiment 2

[0068] As yet another embodiment of the present invention, different from the previous embodiment:

[0069] In step S01 of this embodiment, specifically take 1 ton of municipal sludge, and use a plate and frame filter press to first filter the municipal sludge to dehydrate the municipal sludge, and obtain 10 kg of dewatered sludge with a moisture content of 50%. , Put the dewatered sludge into the chain furnace and incinerate completely at an ambient temperature of 850°C. After the incineration is completed, 1kg of incineration ash will be obtained.

[0070] In step S02 of this embodiment, the concentration of the EDTA solution is 0.02 mol / L, and the addition amount of the EDTA solution is 20 kg. During the leaching process, after stirring for 90 minutes, let it stand for 90 minutes, and filter to obtain 0.95 kg of the first leaching residue.

[0071] In step S03 of this embodiment, the concentration of the sulfuric acid solution is 0.5 mol / L, and the addition amount of the s...

Embodiment 3

[0079] As yet another embodiment of the present invention, different from Embodiment 1,

[0080] In step S01 of this embodiment, specifically take 2 tons of municipal sludge, and use a plate and frame filter press to first filter the municipal sludge to dehydrate the municipal sludge, and obtain 10 kg of dewatered sludge with a moisture content of 50%. , Put the dewatered sludge into the chain furnace and incinerate completely at an ambient temperature of 900°C. After the incineration is completed, 2kg of incineration ash will be obtained.

[0081] In step S02 of this embodiment, the concentration of the EDTA solution is 0.02 mol / L, and the addition amount of the EDTA solution is 40 kg. During the leaching process, after stirring for 90 minutes, let it stand for 90 minutes, and filter to obtain 1.9 kg of first leaching residue.

[0082] In step S03 of this embodiment, the concentration of the sulfuric acid solution was 0.3 mol / L, and the addition amount of the sulfuric acid s...

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Abstract

The invention provides a method for preparing a phosphate fertilizer from municipal sludge. The method comprises the following steps: incinerating municipal sludge to obtain incineration ash; leachingthe incineration ash by using an ethylenediamine tetraacetic acid solution; filtering to obtain first leaching residue; leaching the first leaching residue by using a sulfuric acid solution; filtering to obtain a second leaching solution; adding a sodium hydroxide solution into the second leaching solution; filtering to obtain a third precipitate, dissolving the third precipitate with a hydrochloric acid solution to obtain a solution; adding cation exchange resin into the dissolved solution; filtering to obtain a fourth leaching solution; and adding charcoal into the fourth leaching solutionand obtaining the phosphate fertilizer by crystallization. According to the method, heavy metal components in the municipal sludge can be effectively chelated, phosphorus is dissolved, the purity of phosphorus in the leachate is improved, the phosphorus element is conveniently converted into amorphous precipitate, metal cations in the re-dissolved solution are removed by cation exchange resin, finally the charcoal adsorbs the phosphorus element, the phosphorus is enriched in the charcoal containing a large number of nutrient elements, and the phosphate fertilizer is obtained through crystallization and thus the method has very good practicability.

Description

technical field [0001] The invention relates to the technical field of solid waste recycling, in particular to a method for preparing phosphate fertilizer from municipal sludge. Background technique [0002] Sewage treatment plant sludge is a common solid waste produced during the purification of urban domestic sewage and industrial wastewater. If it cannot be treated and controlled thoroughly, it will cause serious environmental pollution. How to treat and dispose of municipal sludge has become a problem faced by the world of urban economy and environment. At the same time, phosphorus, as a one-way flow element in the biosphere, is indispensable to all life forms, especially in the process of food production, but with the large demand for resources due to social development, phosphorus resources are consumed at an extremely fast rate, and related investigations It is pointed out that the global phosphorus resources will gradually be exhausted within 100 years. [0003] R...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C05B17/00C05F7/00
CPCC05B17/00C05F7/00Y02A40/20
Inventor 李江山薛强马梓涵潘智生
Owner INST OF ROCK & SOIL MECHANICS CHINESE ACAD OF SCI
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