Method for degrading heavy metals in sludge through alkaline hydrolysis-electrolysis combination

A heavy metal and sludge technology, which is applied in the direction of electrochemical sludge treatment, sludge treatment, chemical instruments and methods, etc., can solve the problems of inability to be recycled in agriculture, long storage time, and increased heavy metal content, and achieve economic stability and reliability. The effect of short degradation cycle and cost control

Inactive Publication Date: 2021-06-11
DALIAN UNIV OF TECH
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Problems solved by technology

[0011] The purpose of the present invention is to propose a method for degrading heavy metals in sludge by combined use of alkaline hydrolysis and electrolysis, which can effectively solve the problem of increased content of heavy metals after deposition due to the large amount of sludge and long storage time, which cannot be directly used for agricultural recycling At the same time, it realizes the reduction and resource utilization of excessive excess sludge, and provides an electrochemical treatment method for the treatment of heavy metals in sludge.

Method used

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  • Method for degrading heavy metals in sludge through alkaline hydrolysis-electrolysis combination

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Embodiment 1

[0021] (1) Hot-alkali hydrolysis: Take the remaining sludge from the secondary sedimentation tank of the sewage treatment plant and sieve it to remove the leaves and other clogged pipe substances. After standing overnight, pour off the supernatant and measure the sludge parameters. The TCOD content of the sludge is 13392.02mg / L. Configure 1mol / L NaOH solution, slowly adjust the pH of the sludge solution to 13, and place it in a shaker at 30°C and 150rpm to fully react to fully crack the sludge cells. After 12 hours, the sludge TCOD increased by 55.1%.

[0022] (2) Electrolysis: Potassium dihydrogen phosphate is used as the electrolyte, and the concentration of the electrolyte potassium dihydrogen phosphate contained in the sludge solution is controlled to be 0.1mol / L. The sludge hydrolyzate after adding alkali and shaking for 12 hours is added to the electrolytic cell, and The circulation pump ensures that the solution can fully flow during the entire electrolysis process, an...

Embodiment 2

[0025] (1) Thermal alkaline hydrolysis: Take the remaining sludge from the secondary sedimentation tank of the sewage treatment plant, sieve it, settle it, and discard the supernatant, and measure the TCOD content of the sludge to be 13392.02mg / L. Configure 1mol / L NaOH solution, slowly adjust the pH of the sludge solution to 14, and place it in a shaker at 30°C and 150rpm to fully react to fully break down the sludge cells. After 12 hours, the sludge TCOD increased by 57.2%.

[0026] (2) Electrolysis: Potassium dihydrogen phosphate is used as the electrolyte, and the concentration of the electrolyte potassium dihydrogen phosphate contained in the sludge solution is controlled to be 0.1mol / L. The sludge hydrolyzate after adding alkali and shaking for 12 hours is added to the electrolytic cell, and The circulation pump ensures that the solution can fully flow during the entire electrolysis process, and the rotation speed of the circulation pump is adjusted to 40rpm. The rutheniu...

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Abstract

The invention provides a method for degrading heavy metals in sludge through alkaline hydrolysis-electrolysis combination, and belongs to the technical field of sludge resource utilization. Sludge in a secondary sedimentation tank of a sewage treatment plant is sieved and settled, supernate is removed, microorganisms in the sludge are subjected to cell breaking by adopting a hot-alkali combined method, internal dissolved substances in the microorganisms are released, and a sludge lysate is prepared. An electrolyte is added into the sludge lysate solution in which the heavy metals in the microbial cells are released, and an electric field and a circulating device are externally added. According to the method, microbial cells are broken through the heat-alkali combined method, intracellular heavy metals are released, and then the concentration of the heavy metals in the sludge hydrolysate is effectively degraded through electrolysis. The electrochemical method is short in degradation period, simple in equipment, low in energy consumption and free of secondary pollution, subsequent sludge resource reutilization is facilitated, the cost can be controlled by controlling electrolysis operation parameters, and the disclosed method is economical, stable and reliable.

Description

technical field [0001] The invention relates to a method for degrading heavy metals in sludge by combined alkaline hydrolysis and electrolysis, and belongs to the technical field of sludge resource utilization. Background technique [0002] In recent years, the total amount of wastewater discharge in my country has been increasing year by year, and the construction of a large number of sewage treatment plants has effectively alleviated the pollution of sewage to the environment. However, a large amount of sludge will be generated in the process of treating sewage with activated sludge and other methods. [0003] Since sludge is rich in nitrogen, phosphorus, potassium, amino acids and other essential nutrients for crop growth, the prospect of resource utilization is very broad. However, after the sewage is treated, more than half of the heavy metals are transferred from the sewage to the sludge due to adsorption and precipitation. Although the concentration of heavy metals is...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F11/00C02F101/20
CPCC02F11/006C02F11/00C02F2101/20
Inventor 周集体柳懿函
Owner DALIAN UNIV OF TECH
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