Sludge treatment method and agricultural sludge biochar acquired by adopting same

A treatment method and sludge technology, applied in chemical instruments and methods, carbon compounds, inorganic chemistry, etc., can solve the problems of plant nutrient loss, low product yield, poor economy, etc. The effect of high content and total reduction

Active Publication Date: 2014-01-22
SOUTH CHINA AGRI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] High-temperature carbonization of sludge can effectively remove organic pollutants, kill pathogenic bacteria and passivate heavy metals, but due to the concentration of heavy metals due to high-temperature carbonization, the total amount of heavy metals in carbonization products is large The range increases, often exceeding the agricultural standard, so the product target of the existing sludge carbonization technology is mostly activated carbon (CN 102745687 A; CN102432007 A; CN102530941 A)
At the same time, high-temperature carbonization causes serious loss of plant nutrients in municipal sludge, low product yield, and poor economic efficiency

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Example 1 Preparation of agricultural sludge biochar with 10% fly ash added

[0038] Take 500kg of wet sludge with a water content of 80% and mix it evenly with 10kg of fly ash, air-dry or dry it until the water content is less than 15%, crush it through a 60-mesh sieve; put it into the sludge carbonization furnace, and heat it to 280 under the protection of nitrogen ℃, maintain the temperature for 120 minutes, and cool to obtain the agricultural sludge biochar product.

[0039]The total contents of heavy metals Pb, Cd, As, Cr, Cu, Hg, Zn and Ni in the product are: Pb-631.4 mg / kg, Cd-9.3 mg / kg, As-61.5 mg / kg, Cr-700.6 mg / kg , Cu-911.7 mg / kg, Hg-0.00 mg / kg, Zn-1161.8 mg / kg, Ni-147.6 mg / kg; the content of effective heavy metals in the product is 83%~100% lower than that of the original sludge; the total amount of nitrogen in the sludge Phosphorus and potassium (calculated on a dry basis) are N-2.75%, P 2 o 5 -3.55%, K 2 O-1.21; the content of polycyclic aromatic...

Embodiment 2

[0040] Example 2 Preparation of agricultural sludge biochar with 3% weathered coal added

[0041] Take 100kg of dry sludge with a water content of less than 15% and 3kg of weathered coal (organic matter content 35%), mix evenly, crush and pass through a 60-mesh sieve; put it into the sludge carbonization furnace, and heat it to 350°C under nitrogen protection to maintain the temperature After cooling for 60 minutes, the agricultural sludge biochar product is obtained.

[0042] The total contents of heavy metals Pb, Cd, As, Cr, Cu, Hg, Zn and Ni in the product are: Pb-640.0 mg / kg, Cd-9.9 mg / kg, As-62.3 mg / kg, Cr-715.4 mg / kg , Cu-932.6 mg / kg, Hg-0.00 mg / kg, Zn-1182.4 mg / kg, Ni-148.5mg / kg; the content of effective heavy metals in the product is 85%~100% lower than that of the original sludge; the total amount of nitrogen in the sludge Phosphorus and potassium (calculated on a dry basis) are N-2.68%, P 2 o 5 -3.96%, K 2 O-1.43; the content of polycyclic aromatic hydrocar...

Embodiment 3

[0043] Example 3 Preparation of Agricultural Sludge Biochar Added with 20% Sodium Lignosulfonate and Phosphogypsum

[0044] Take 10kg of sodium lignosulfonate and 10kg of phosphogypsum, mix them evenly, add 500kg of wet sludge with a water content of 80% and mix evenly, air-dry or dry until the water content is less than 15%, crush and pass through a 60-mesh sieve; put into the sludge for carbonization Furnace, under the protection of nitrogen, heated to 420 ° C, maintained at this temperature for 40 minutes, cooled, to obtain agricultural sludge biochar products.

[0045] The total contents of heavy metals Pb, Cd, As, Cr, Cu, Hg, Zn and Ni in the product are: Pb-585.6 mg / kg, Cd-8.65 mg / kg, As-56.2 mg / kg, Cr-620.7 mg / kg , Cu-800.2 mg / kg, Hg-0.00 mg / kg, Zn-996.8 mg / kg, Ni-125.7 mg / kg; the content of effective heavy metals in the product is 90%~100% lower than that of the original sludge; the total amount of nitrogen in the sludge Phosphorus and potassium (calculated on a...

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Abstract

The invention discloses a sludge treatment method and an agricultural sludge biochar acquired by adopting the method. The agricultural sludge biochar is mainly prepared through low-temperature oxygen-limited decomposition of organic and inorganic antidotes and citizen sludge which are uniformly mixed, and the antidotes accounts for 3%-20% of the amount of dry matter of the citizen sludge. With the adoption of the sludge treatment method, activity and total amount of heavy metal in a carbonized product can be effectively reduced, pathogenic bacteria are killed, organic pollutants such as polycyclic aromatic hydrocarbon and the like are eliminated, and nutrients can be maintained to the greatest extent, so that the product is applicable to the plantation fields such as agriculture, forestry and the like.

Description

technical field [0001] The invention belongs to the field of agricultural and forestry biochar, and in particular relates to a sludge treatment method and the obtained agricultural sludge biochar. Background technique [0002] According to the "Twelfth Five-Year Plan" National Urban Sewage Treatment and Recycling Facilities Construction Plan, my country's urban sewage treatment capacity will reach 75.94 billion m in 2015 3 According to the current average operating load of 82.5% and the sludge production volume accounting for 0.02% of the sewage volume, the annual sludge production will reach 12.53 million tons. The proper disposal rate of urban sludge in my country is very low. In 2010, the harmless treatment rate of sludge was less than 25% (General Office of the State Council, 2012). It has become a new source of environmental pollution in my country's soil and water environment. It is of great significance to promote the sustainable and healthy development of sewage trea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/08C05D9/00C01B32/324
Inventor 毛小云王君陈娴桂丕冯新
Owner SOUTH CHINA AGRI UNIV
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