Pretreatment method of heavy metal sludge

A heavy metal sludge and pretreatment technology, applied in sludge treatment, water/sludge/sewage treatment, dehydration/drying/thickened sludge treatment, etc., can solve the problem of reducing the moisture content of sludge, excessive heavy metals, and cannot be directly filled Buried and other issues

Inactive Publication Date: 2015-04-08
扬州杰嘉工业固废处置有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The technical problem to be solved by the present invention is to provide a heavy metal sludge pretreatment method that can not only remove heavy metals in sludge but also greatly reduce the water content of sludge. The problem that exceeding the standard cannot be directly landfilled

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] The sludge treated in this example comes from the physical and chemical treatment section of a sewage treatment company in a chemical industry park. After analysis, the moisture content of the sludge is 98%, and the copper content in the leaching solution of the leaching toxicity analysis is 84mg / L.

[0039] Add hydrated lime powder to 500ml of sludge under stirring until the pH value is 8.5, then add 1.5g of industrial sodium sulfide, and continue stirring for 3 minutes; then add 5g of cement, and continue stirring for 5 minutes; then add flocculant PAM (0.5%) 0.5 ml, stirred for 2 minutes and left to stand to make the sludge flocculate and precipitate rapidly; after vacuum filtration, the moisture content of the sludge was 43%, and after 2 days of natural drying, the sludge was lumpy with a moisture content of 36%.

[0040] The mud cake has been tested for leaching toxicity, and the copper content in the mud cake leachate is 1mg / L, which meets the limit requirements fo...

Embodiment 2

[0043]The sludge treated in this example comes from a landfill leachate treatment workshop. After analysis, the moisture content of the sludge is 90%. The copper content in the leaching solution of the leaching toxicity analysis is 57mg / L, the zinc content is 78mg / L, and the nickel content is 4mg / L. L.

[0044] Add slaked lime powder to 500ml of sludge under stirring to adjust the pH value to 8.9; then add 2g of heavy metal chelating agent (concentration 15%), stir for 3 minutes, add 5g of cement, and continue stirring for 5 minutes; then add 0.5ml of flocculant PAM , Stir for 1 minute to quickly flocculate and precipitate the sludge; after vacuum filtration, the moisture content of the sludge is 49%, and after 2 days of natural drying, the sludge is in the form of hard lumps with a moisture content of 38%.

[0045] After the leaching toxicity analysis of the mud cake, the copper content in the leaching solution is 1mg / L, the zinc content is 1.2mg / L, and the nickel content is ...

Embodiment 3

[0048] The sludge treated in this example comes from a sewage treatment workshop of a chemical plant. After analysis, the moisture content of the sludge is 95%, and the lead content in the leaching solution of the leaching toxicity analysis is 46mg / L.

[0049] Add slaked lime powder to 500ml of sludge under stirring, and the pH value is 7.9; then add 0.5g of industrial thiourea, stir for 5 minutes, then add 5g of cement, and continue stirring for 5 minutes; then add 0.5ml of flocculant PAM, and stir for 1 minute , so that the sludge quickly flocculates and precipitates; after vacuum filtration, the moisture content of the sludge is 55%, and after 2 days of natural drying, the mud cake is hard and lumpy, with a water content of 32%.

[0050] After entering and exiting the toxicity analysis of the mud cake, the lead content in the leachate is 0.04mg / L, which meets the requirements of the "Hazardous Waste Landfill Pollution Control Standard" (GB 18598-2001).

[0051] The separate...

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PUM

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Abstract

The invention relates to a pretreatment method of heavy metal sludge. The specific method comprises the following steps: firstly, adjusting the pH of sewage sludge to be 7-9 with slaked lime, and treating with a heavy metal stabilization medicine; adding cement and a flocculating agent, and stirring; finally separating out a lot of water from which metals are removed by virtue of mud-water separation equipment; and naturally drying a mud cake for 1-2 days until the mud cake becomes hard, wherein the moisture content is lower than 40%, the mud cake can be directly subjected to landfill disposal, and the content of heavy metals in the separated sewage accords with the related emission limit in the 'integrated wastewater discharge standard'. Therefore, the method can be used as a pretreatment unit before landfill disposal of high-water sludge and heavy metal-containing sludge.

Description

technical field [0001] The invention relates to a pretreatment technology for dehydration and metal removal of sewage treatment sludge. Background technique [0002] With the further acceleration of the urbanization process, the pollution of urban domestic sewage and industrial wastewater to the environment is becoming more and more serious. In order to reduce water pollution, a large number of large, medium and small cities across the country have built additional sewage treatment plants, accompanied by sewage treatment. A large amount of sludge is produced in the process, and the arbitrary stacking of sludge not only takes up a lot of land, but also causes secondary pollution. Sludge contains heavy metals that are harmful to humans and animals. Unlike other pollutants, heavy metals cannot be degraded by microorganisms. Once they enter the soil, they are easily absorbed by crops and accumulate in plants, eventually causing harm to humans and animals through the fo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F11/00C02F11/14
CPCC02F11/00C02F11/14C02F2101/20
Inventor 岳喜龙郭杰仲鹏鹏樊红杰肖世健何品晶
Owner 扬州杰嘉工业固废处置有限公司
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