Method for reducing nitrogen loss in municipal sludge composting process

A municipal sludge and composting technology, applied in the field of environmental engineering, can solve the problems of high environmental requirements for ion concentration generation and difficult operation, and achieve the effects of reducing the escape of ammonia gas, strong operability, and enhanced concentration

Inactive Publication Date: 2019-07-05
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the generation of magnesium ammonium phosphate has relatively high requirements on the concentration of ions in the pile and the generation environment, and the actual operation is more difficult.

Method used

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  • Method for reducing nitrogen loss in municipal sludge composting process
  • Method for reducing nitrogen loss in municipal sludge composting process
  • Method for reducing nitrogen loss in municipal sludge composting process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Raw materials for composting: 2kg of dewatered sludge (water content 80%, dry weight of dewatered sludge 0.4kg) from a city sewage treatment, 0.65kg of sawdust as conditioner, phosphate buffer solution containing 0.1mol potassium monohydrogen phosphate and 0.1 200 ml of a solution of potassium dihydrogen phosphate with a pH of 6.8.

[0033] The above raw materials are attached figure 1 The process flow shown is mixed, and after mixing, the compost with a moisture content of 65% is put into the tank for forced ventilation static composting, and the ventilation rate is 0.2L / min / kg dry weight of the material. Compost for 30 days and turn over every 6 days.

[0034] During composting, samples were taken every 6 days to measure the moisture content, ammonium nitrogen, nitrate nitrogen, total nitrogen and organic matter of the compost. The experimental results showed that when no phosphate buffer was added, the nitrogen loss of sludge compost was 65.3%, and the nitrogen lo...

Embodiment 2

[0036] Composting raw materials: 2kg of dewatered sludge (water content 85%, dry weight of dewatered sludge 0.3kg) from a city sewage treatment, 1.3kg of straw as a conditioner, phosphate buffer solution containing 0.018mol sodium monohydrogen phosphate and 0.132 mol of sodium dihydrogen phosphate pH 6.0 solution 200 ml.

[0037] The above raw materials are attached figure 1 The process flow shown is mixed, and after mixing, the compost with a moisture content of 55% is put into the tank for forced ventilation static composting, and the ventilation rate is 0.4L / min / kg dry weight of the material. Compost for 20 days and turn over every 4 days.

[0038] During the composting period, samples were taken every 4 days to measure the moisture content, ammonium nitrogen, nitrate nitrogen, total nitrogen and organic matter of the compost. The experimental results showed that when no phosphate buffer was added, the nitrogen loss of sludge compost was 60.3%, and the nitrogen loss of add...

Embodiment 3

[0040] Compost raw materials: 2kg of dewatered sludge (water content 82.0%, dry weight of dewatered sludge 0.36kg) from a city sewage treatment, conditioner is 0.8kg of sawdust, phosphate buffer solution contains 0.114mol sodium monohydrogen phosphate and 0.006 200 ml of a solution of potassium dihydrogen phosphate with a pH of 8.0.

[0041] The above raw materials are attached figure 1 The process flow shown is mixed, and after mixing, the compost with a moisture content of 62.5% is put into the tank for forced ventilation static composting, and the ventilation rate is 0.3L / min / kg dry weight of the material. Compost for 25 days and turn over every 5 days.

[0042] During the composting period, samples were taken every 5 days to measure the moisture content, ammonium nitrogen, nitrate nitrogen, total nitrogen and organic matter of the compost. The experimental results showed that when no phosphate buffer was added, the nitrogen loss of sludge compost was 64.3%, and the nitr...

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Abstract

The invention relates to the field of urban sludge treatment and provides a method for reducing nitrogen loss in a municipal sludge composting process. The method comprises the following steps that dewatered sludge is uniformly mixed with a phosphate buffer solution, and then a conditioning agent is added for adjusting the water content and mixed uniformly to obtain a mixed material; the uniformlymixed material is subjected to composting treatment, and forced ventilation is carried out for oxygen supply during composting treatment. According to the method, by adding the phosphate buffer solution into the municipal sludge, the nitrogen loss in the composting process is reduced while the degradation rate of organic matter in sludge compost is increased. When an appropriate quantity of the phosphate buffer solution is added into the municipal sludge, the conversion of loose extracellular polymers to the soluble organic matter can be accelerated so that bioavailable carbon in a compost body can be increased. Ammonia assimilation bacteria in the compost body can convert more ammonium nitrogen into organic nitrogen in the presence of more available carbon sources, so that nitrogen is fixed into the compost body, and the nitrogen loss during composting is reduced.

Description

technical field [0001] The invention belongs to the technical field of environmental engineering, and in particular relates to a method for reducing nitrogen loss during urban sludge composting. Background technique [0002] Municipal sludge is liquid, semi-solid and solid waste produced in the process of treating municipal sewage by activated sludge method. It is mainly composed of organic phase, inorganic phase and water. The sludge contains a large amount of persistent organic matter, easily degradable organic matter, Heavy metals, malodorous substances, parasite eggs and pathogens, etc. Therefore, the sludge needs to be harmless and stabilized before being discharged into the environment. Sludge composting treatment is a kind of sludge stabilization treatment. After composting, sludge can be used in arable land, garden land and pasture land, etc., turning waste into treasure. The composting of municipal sludge is beneficial to save resources and achieve sustainable deve...

Claims

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Application Information

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IPC IPC(8): C05F7/00C05F17/00C05G1/00
CPCC05B7/00C05F7/00C05F17/00Y02A40/20Y02W30/40
Inventor 沈雁文寿宗奇朱南文
Owner SHANGHAI JIAO TONG UNIV
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