Process for preparing active carbon by adding husks into chemical sludge

A technology for preparing activated carbon and chemical sludge, applied in sludge treatment, water/sludge/sewage treatment, chemical instruments and methods, etc., can solve problems such as secondary pollution, endangering the ecological environment, occupying farmland, etc., and achieve a good environment and social benefits, the effects of a wide range of sources

Inactive Publication Date: 2011-06-29
NANJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The cost of chemical sludge incineration in my country is high, and many chemical companies turn to landfill or compost to dispose of the remaining sludge. Because the sludge contains a large amount of organic toxic substances, landfill or compost is likely to cause serious secondary pollution and endanger the ecological environment. Compost takes up a lot of farmland

Method used

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  • Process for preparing active carbon by adding husks into chemical sludge

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Take the residual sludge of a petrochemical plant with a mass moisture content of 75%, dry it at 120°C for 6 hours, weigh 1kg of dried sludge, add 5g of coconut shell in turn, grind until the average particle size is 0.71mm, and then add 0.5L to a concentration of 3mol / L potassium hydroxide activation solution; soak and activate at 90°C for 4h, stir at 150r / min while activating, and dry (dry at 120°C for 4h). Under the protection of 600°C (heating rate of 15°C / min) and nitrogen purge rate of 150mL / min, pyrolysis was carried out for 3h. Cool, wash with 1mol / L hydrochloric acid, and dry; then wash with water, and dry to obtain activated carbon. The measured specific surface area is: 441m 2 / g, the leaching concentration of heavy metals is shown in Table 1.

Embodiment 2

[0027] Take the residual sludge from a sewage treatment plant of a pesticide factory with a mass moisture content of 80%, dry it at 110°C for 8 hours, weigh 1kg of dried sludge, add 15g of apricot kernels in turn, grind until the average particle size is 0.50mm, and then add 1L concentration Potassium hydroxide and zinc chloride solutions of 3 mol / L; soak and activate at 85°C for 6h, stir at 100r / min while activating, and dry (dry at 110°C for 8h). Under the protection of 700°C (heating rate of 10°C / min) and helium purge rate of 100mL / min, pyrolysis was carried out for 2.5h. Cool, wash with 0.8mol / L hydrochloric acid, and dry; then wash with water, and dry to obtain activated carbon. The measured specific surface area is: 465m 2 / g, the leaching concentration of heavy metals is shown in Table 1.

Embodiment 3

[0029] Take the residual sludge of a sewage treatment plant of a pharmaceutical and chemical factory with a mass moisture content of 85%, dry it at 105°C for 24 hours, weigh 1kg of dried sludge, add 30g of peach pits in turn, grind until the average particle size is 0.15mm, and then add 2L Potassium sulfide solution with a concentration of 1mol / L; soak and activate at 75°C for 8h, and dry at 200r / min while activating (dry at 105°C for 24h). Under the protection of 800°C (heating rate of 20°C / min) and argon purge rate of 180mL / min, pyrolysis was carried out for 5h. Cool, wash with 1.5mol / L hydrochloric acid, and dry; then wash with water, and dry to obtain activated carbon. The measured specific surface area is: 510m 2 / g, the leaching concentration of heavy metals is shown in Table 1.

[0030] Table 1 Analysis of heavy metal content in leaching solution in activated carbon leaching toxicity identification test

[0031]

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Abstract

The invention relates to a process for preparing active carbon by adding husks into chemical sludge. The process comprises the following steps of: drying residual sludge which is generated from sewage treatment in chemical industry and serves as a raw material; adding the husks; grinding; adding an activating agent; drying; performing carbonizing activation under the protection of inert gases; and cooling, washing and drying to prepare sludge-based active carbon. The active carbon is prepared from a great deal of the residual sludge which is generated from sewage treatment in chemical industry and serves as the raw material, so the discharge value of the residual sludge in the chemical industry is reduced, preparation cost of an active carbon adsorbent is reduced, and obvious environmental and economic benefits are achieved. The heavy metal concentration of the prepared active carbon is lower than the highest allowable leachate concentration stated in national standard GB 5085.3-2007 (hazardous waste identification standard leaching toxicity identification); and under a high-temperature pyrolysis condition, organic matters in the sludge can be completely mineralized. The active carbon prepared by the process can be applied in the fields of wastewater treatment, waste gas absorption and the like and has a wide market prospect.

Description

technical field [0001] The invention relates to resource disposal of industrial solid waste, in particular to a process for preparing activated carbon by adding fruit shells to chemical sludge. Background technique [0002] The sludge in the chemical industry is not only bulky, but also contains high organic poisons, fine particles, flocculent colloidal structure, and high hydrophilicity. There are more than 1,000 large and small chemical parks in my country, with more than 100,000 large and small chemical enterprises. These chemical companies produce tens of thousands of tons of excess sludge every day, and the water content of the sludge is as high as 95%. After the sludge is filtered by belt filter, the water content drops to 70-85%, because it contains various organic poisons and heavy metals. . According to the latest "National Hazardous Waste List" promulgated by our country, the residual sludge generated in the process of wastewater treatment in chemical, pharmaceut...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/12C02F11/00
Inventor 徐炎华胡俊赵浩
Owner NANJING UNIV OF TECH
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