Novel method for processing dioxins in fly ash

A new method, fly ash technology, applied in separation methods, chemical instruments and methods, dispersed particle separation, etc., can solve the problems of high energy consumption, complex operation and high cost

Active Publication Date: 2008-10-29
深圳龙澄高科技环保股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The Department of Electrical Engineering and Applied Electronics Technology of Tsinghua University conducted a preliminary study on low-temperature plasma treatment of dioxins in dust, and the Department of Chemistry of Zhangjiakou Normal University conducted a study on the decomposition of dioxins in fly ash using supercritical water oxidation technology. The applicability of the two methods in China also has the problems of high cost and complicated operation
The Department of Environmental Science and Engineering of Tsinghua University conducted an attempt to catalyze the decomposition of dioxins in fly ash with low-temperature chemicals. The dechlorination efficiency of oxins is higher than 99%. This technology realizes the control of dioxins in fly ash. It is a more practical technology for the removal of dioxins in solid waste, but this technology also has energy consumption. Large size, high cost, and easy to produce toxic gas

Method used

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  • Novel method for processing dioxins in fly ash

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] 1. Collect fly ash from municipal solid waste incinerators, detect and analyze the content of dioxins in the fly ash, and store it in the same way as cement (anti-moisture absorption and hardening);

[0028] 2. Add 2.0 kg of 1.0% sodium dodecylsulfonate aqueous solution to 400 g of fly ash, and stir for 60 min with a propeller-type agitator whose rotation speed is 100 RPM;

[0029] 3. Separate and extract the sodium dodecylsulfonate aqueous solution containing dioxins from the fly ash suspension by vacuum filtration;

[0030] 4. Add a certain amount of hydrochloric acid to the extract to adjust the pH of the solution to 4.0;

[0031] 5. Heat the extract and maintain the temperature at 99°C±1°C;

[0032] 6. Pass 0.8 (v / v.min) air into the extract for 98 hours continuously;

[0033] 7. Take a sample to detect and analyze the content of dioxins in the liquid, then add lime to neutralize the acidic extract until the pH is 5.5-7.0 and then discharge.

[0034] The degradat...

Embodiment 2

[0042] 1. Collect urban solid waste incineration fly ash, detect and analyze the content of dioxins in the fly ash, and store it in the same way as cement (anti-moisture absorption and hardening);

[0043] 2. Add 50 kg of 0.01% lauryl betaine aqueous solution to 50 kg of fly ash, and stir for 30 min with a cement mortar mixer with a rotation speed of 100 RPM;

[0044] 3. Using a plate and frame filter to separate and extract the dodecyl betaine solution containing dioxins from the fly ash suspension;

[0045] 4. Add a certain amount of sulfuric acid to the extract to adjust the pH of the solution to 6.0;

[0046] 5. Heat the extract and maintain the temperature at 50°C ± 1°C; after reacting under 4 conditions for 48 hours, take a sample to detect and analyze the content of dioxins in the liquid.

[0047] The degradation rate of dioxin-like substances in fly ash is calculated from the above formula (1), and the result shows that the degradation rate of dioxin-like substances i...

Embodiment 3

[0049] 1. Collect fly ash from municipal solid waste incinerators, detect and analyze the content of dioxins in the fly ash, and store it in the same way as cement (anti-moisture absorption and hardening);

[0050] 2. Add 2.0kg of soapy water containing 0.1% soap to 400g of fly ash and stir for 10 minutes;

[0051] 3. Separation and extraction of soapy water containing dioxins from the fly ash suspension by gravity suction filtration;

[0052] 4. Add a certain amount of hydrochloric acid to the extract, adjust the pH value of the solution to 5.5, then heat and maintain it at 30°C ± 1°C, and pass air into the solution for 24 hours;

[0053] 5. Sampling, detection and analysis of the content of dioxin-like substances in the liquid, the degradation rate of dioxin-like substances in fly ash was calculated by formula (1), and the results showed that the destruction and degradation rate of dioxin-like substances in fly ash was 72% .

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Abstract

The present invention discloses an economical and high-efficiency method of decomposing dioxin of fly ash in the waste incinerator without causing secondary pollution and the decomposition rate of dioxin and other similar substances can reach 70 to 99 percent after treatment. An aqueous surfactant solution is used for extracting the dioxin in fly ash so as to separate the dioxin from fly ash; after acidification, the extract with abundant dioxin is heated to 30 to 100 DEG C under the condition of pumping in oxygen or oxygen enriched air; only 1 to 100-hour treatment can destroy the dioxin by oxidative degradation. The waste incinerator fly ash treated by the method, which then is treated by the patent technology 'a stabilization and resource recycling method of urban waste incinerator fly ash' disclosed by the inventor (Patent application number: 200710073815.2), can be used as the fine aggregate of concrete or cement mortar, or directly buried in a waste landfill site.

Description

Technical field: [0001] The invention belongs to the technical field of hazardous solid waste treatment and resource utilization, and in particular relates to a method for removing dioxin, one of the main harmful and toxic substances in fly ash of municipal solid waste incinerators. Background technique: [0002] With the extensive promotion of domestic municipal solid waste incineration technology, the amount of fly ash produced by incinerators is increasing day by day. This kind of fly ash not only enriches a large amount of toxic heavy metals such as mercury, cadmium, and lead, but also enriches a large amount of dioxins, so it is clearly stipulated as dangerous by the "Pollution Control Standards for Domestic Waste Incineration" (GB 18485-2001). Waste must be stabilized and harmless before final disposal. [0003] The research on the removal or stabilization treatment technology of heavy metals in fly ash has become a hot spot in the field of environmental protection at...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D53/75B01D53/86
Inventor 张涉马辉文童立恒汪春霞孟丽娜黄卓李欣范敏
Owner 深圳龙澄高科技环保股份有限公司
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