Ozone-hydroxyl free radical combined catalytic oxidation sludge conditioning method

Abstract

The invention discloses an ozone-hydroxyl free radical combined catalytic oxidation sludge conditioning method. The method includes following steps: adding sludge with water content of 92-99.5% into a mixed solution of ferrous sulfate heptahydrate and sulfamic acid for mixing reaction; adding a liquid-state hydrogen peroxide for mixing reaction; enabling a product after reaction to enter a reinforced reaction tank for aeration treatment to realize sludge oxidation wall breaking, wherein gas is generated by a low-temperature plasma reactor and contains ozone and hydroxyl free radicals and free electrons; enabling a sludge product after treatment to enter a plate-and-frame filter press for press filtering to obtain a sludge cake with water content of 50-62%. The hydroxyl free radicals generated by a sludge conditioning agent used in the method has good oxidizing performance and can damage extracellular polymeric substance and cell walls, bound water bound in the sludge is released to be free water, and the existence form of water in the sludge is changed; a water filtering passage in the dewatering process of the sludge is built, so that dewatering of the sludge is smoother, and the water content of the sludge cake is ensured to stably reach standards. An aeration system in the reaction tank can further realize sludge oxidation wall-breaking effect, so that consumption of the two agents is lowered.

Description

Technical field [0001] The present invention relates to the technical field of sludge treatment, in particular to a method for conditioning sludge by combined catalytic oxidation of ozone and hydroxyl radicals. Background technique [0002] Sludge is a solid-liquid mixture, and its solid-liquid ratio is relatively stable without external intervention. The sludge is easy to decompose and odor, with finer particles, small specific gravity (about 1.02-1.06), high water content and not easy to dehydrate, and is a hydrophilic substance with a gel-pack structure. [0003] The characteristics of sludge from municipal wastewater treatment plants in my country are: 1) large amount of sludge, large scale of wastewater treatment plant, and concentrated sludge production; 2) low organic matter content and large sediment content; 3) large differences in sludge quality in different regions. As of 2015, the national sewage treatment volume was 78.4 billion tons, and the sludge production volume ...

AI Technical Summary

Problems solved by technology

[0006] (1) Changing the conditioning system leads to a reduction in the processing capacity of the system. First, the conditioning process takes a long time, resulting in a longer cycle of a dehydration plate. Second, the lime used in the conditioning increases the amount of sludge and the effective treatment capacity. reduce;

[0007] (2) The amount of dosing is large, the incident of counterfeit medicine is relatively long, and the workload of dosing is relatively large;

[0008] (3) The amount of lime added to Indonesian sludge is 25-35%, which leads to high post-processing and transportation costs. The specificity of lime makes it difficult to add. The workplace is dusty and the work intensity is high. At the same time, the lime industry It belongs to the state-restricted industry. The production of lime consumes a lot of energy and damages the mountain. It is foreseeable that its price will become higher and higher;

[0009] (4) Ferric chloride is highly corrosive to equipment and pipelines, and will also cause a certain degree of sludge increase;

[0010] (5) The addition of PAM and lime can easily cause blockage of the filter cloth, affecting its water permeability and service life, while increasing the frequency of cleaning, and the work is labor-intensive;

[0011] (6) Due to the large amount of lime used in sludge conditioning, its subsequent disposal and resource utilization are limited

[0012] (7) Higher operating costs