Method for conditioning urban sludge by agent compounding

A technology of municipal sludge and chemicals, applied in sludge treatment, electrochemical sludge treatment, chemical instruments and methods, etc., can solve the problems of increased sludge dry weight, increased cost, and large amount of conditioner

Inactive Publication Date: 2018-05-29
NANCHANG HANGKONG UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In engineering practice, sludge is usually treated with two or more compounds of aluminum salt, iron salt, fly ash, and lime. Although the water content of sludge can be greatly reduced, the amount of conditioning agent is large and greatly increased the dry weight of the sludge after dehydration, and brought new problems to the subsequent treatment and disposal of the sludge
Using the activated persulfate oxidation method alone can effectively break down microbial cells and extracellular polymer EPS, but it cannot form a porous skeleton structure, so the improvement of dehydration performance is limited
Moreover, the cost increase caused by the large dosage will limit its practical application

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The sludge conditioned in this embodiment is A 2 The remaining sludge produced after the treatment of urban domestic sewage by the / O process has a pH of 7.2, a moisture content of 97.77%, a total solid content of 21930mg / L, a volatile solid content of 14010mg / L, and a sludge ratio of The resistance is 1.69×10 13 m / Kg. Take 500mL of the remaining sludge, adjust the pH to 2.5 with dilute sulfuric acid, add 1.25g iron powder and 1.25g activated carbon powder to it, and start the aeration device, stir the reaction time for 20min, the stirring reaction temperature is 25°C, and the stirring speed is 200r / min; then add 1.67g of sodium persulfate to fully dissolve, stir for 20min, the stirring reaction temperature is 25°C, and the stirring speed is 180r / min. Then take 100mL of the conditioned sludge and use the Buchner funnel-vacuum filtration method to conduct the sludge specific resistance test, and record the filtration time. Another 100mL of the sludge was not conditio...

Embodiment 2

[0020] The sludge conditioned in this embodiment is the residual sludge produced by the oxidation ditch process for treating urban domestic sewage, with a pH value of 6.7, a moisture content of the sludge of 96%, a total solid content of the sludge of 20100 mg / L, and a volatile solid content of 13510 mg / L, the sludge specific resistance is 2.76×10 13 m / Kg. Get 500mL of the remaining sludge, adjust the pH to 2.9 with dilute sulfuric acid, add 1.32g of iron powder and 1.32g of activated carbon powder therein, and start the aeration device, the stirring reaction time is 20min, the stirring reaction temperature is 25 ° C, and the stirring speed is 240r / min. Then add 1.61 g of sodium persulfate to fully dissolve, stir for 20 minutes, the stirring reaction temperature is 25° C., and the stirring speed is 200 r / min. Then take 100mL of the conditioned sludge and use the Buchner funnel-vacuum filtration method to conduct the sludge specific resistance test, and record the filtration...

Embodiment 3

[0027] The sludge conditioned in this embodiment is A 2 The remaining sludge produced after the / O process treats urban domestic sewage has a pH value of 7.12, a moisture content of the sludge of 98%, a total solid content of the sludge of 19650mg / L, a volatile solid content of 13170mg / L, and a specific resistance of the sludge. 2.14×10 13 m / Kg.

[0028]Get 500mL of the remaining sludge, adjust the pH to 3.1 with dilute sulfuric acid, add 1.28g of iron powder and 1.28g of activated carbon powder therein, and start the aeration device, the stirring reaction time is 20min, the stirring reaction temperature is 25 ° C, and the stirring speed is 230r / min. Then add 1.57g of sodium persulfate to fully dissolve, stir for 20min, the stirring reaction temperature is 25°C, and the stirring speed is 180r / min. Then take 100mL of the conditioned sludge and use the Buchner funnel-vacuum filtration method to conduct the sludge specific resistance test, and record the filtration time. This...

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PUM

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Abstract

The invention discloses a method for conditioning urban sludge by agent compounding. The method comprises (1) adjusting pH through an acid solution, then adding iron powder and activated carbon powderinto sludge, carrying out full stirring mixing, starting an aeration device to condition and transferring a part of substances in the sludge into the liquid phase, (2) adding a persulfate into the sludge conditioned in the previous step, activating the persulfate through ferrous ions, oxidizing to break the sludge so that combined water, adsorbed water, interstitial water and free water in the sludge are partially separated, the dewaterability is improved and SCOD, proteins and polysaccharide in the sludge are increased, and (3) after sludge conditioning, carrying out mechanical dewatering toobtain dewatered sludge. The method can reduce the moisture content of the urban sludge from 97 to 99% to 55 to 60%, greatly reduce the specific resistance and volume of the sludge, greatly improve the combustion calorific value, realize harmlessness, stabilization, reduction and recycling of sludge and has a wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment, and in particular relates to a method for conditioning urban sludge by compounding medicaments applied in the deep dehydration of sludge. Background technique [0002] Municipal sludge is produced along with urban sewage treatment. With the rapid development of my country's society and economy, my country's sewage treatment business has been significantly developed, and the corresponding sludge production has also greatly increased, and the situation of sludge treatment and disposal is becoming more and more severe. As of September 2015, the total amount of sludge in my country has exceeded 30 million tons per year, and the disposal rate is only 56%. The moisture content in the sludge is as high as 95%~99%, the organic matter content is high, and there are also pathogenic bacteria, parasite eggs, heavy metals and some toxic and harmful refractory organic substances, etc. Therefore, afte...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F11/12C02F11/14C02F11/00
CPCC02F11/122C02F11/00C02F11/006C02F11/14
Inventor 吴少林李迪谢霞常人杰王启沛
Owner NANCHANG HANGKONG UNIVERSITY
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