A kind of sludge pretreatment method based on sulfonic acid porphyrin iron catalyst Fenton system

Abstract

The invention discloses a sludge pretreatment method based on a sulfonic acid porphyrin iron catalyst Fenton-like system, comprising the following steps: mixing the sulfonic acid porphyrin iron catalyst, methanol and hydrogen peroxide solution, stirring, and mixing the obtained The liquid is mixed with the sludge for hydrolysis treatment to complete the pretreatment of the sludge. The present invention is based on the sludge pretreatment method of the sulfonic acid porphyrin iron catalyst Fenton system, by first mixing and stirring the sulfonic acid porphyrin iron catalyst, methanol and hydrogen peroxide solution to generate a mixed solution containing high-valent iron species , and then mixed with sludge, using high-valent iron species to achieve effective treatment of sludge, has the advantages of low catalyst and oxidant consumption, mild reaction conditions, high treatment efficiency, good treatment effect, and good adaptability. The effect of resource utilization is of great significance, with high use value and good application prospect.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment, and relates to a sludge pretreatment method based on a sulfonic acid-based porphyrin iron catalyst-like Fenton system. Background technique [0002] The Fenton system is one of the typical advanced oxidation technologies that have been widely proven to promote sludge hydrolysis. The system is that ferrous ions activate hydrogen peroxide to generate hydroxyl radicals, and through this strong oxidizing free radicals, it interacts with them. The extracellular polymer undergoes electron exchange, thereby realizing the rapid decomposition of the extracellular polymer. The oxidation potential of hydroxyl radicals is 2.7-2.8 V, which is much higher than that of hydrogen peroxide (1.76 V), and is the core substance of the Fenton system to promote sludge hydrolysis. The Fenton system is mainly divided into the following processes: 1) ferrous ions react with hydrogen peroxide to generate hydroxyl...

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Problems solved by technology

However, the traditional Fenton system used for sludge pretreatment has the following disadvantages: 1) The pH of sludge is usually around 7, and the iron and ferrous ions in the Fenton system need to maintain their ionic form in a strong acid environment, so in order to Ferric ions and ferrous ions will be quickly separated from the solution in the form of hydroxides. It is necessary to add a large amount of acidic reagents to control the pH of the Fenton reaction between 2-3, which greatly limits the use of the Fenton system. Application in sludge

2) The TS and VS of sludge are high, and the hydrolysis of extracellular polymers and microbial cell walls is difficult, which will cause the input hydrogen peroxide to be consumed by the sludge before contacting ferrous ions. Therefore, the hydrolysis of sludge by the existing Fenton system The capacity is very limited, which also leads to the application of the Fenton system to pretreat sludge requires a higher amount of hydrogen peroxide

3) The cycle of ferric ions and ferrous ions will be affected by the concentration of the two ions. The accumulation of ferric ions makes there not enough ferrous ions to activate hydrogen peroxide, which slows the generation of hydroxyl radicals and reduces the Fenton system. Oxidation ability

However, in the actual research process of the inventors of the present application, it is found that the iron porphyrin-hydrogen peroxide Fenton system pretreatment sludge still has the following defects: 1) the high solid characteristics of the sludge have no effect on metalloporphyrin-like fentons. The reagent diffusion and mass transfer efficiency of the sludge system have negative effects, resulting in the hindering of hydroxyl substitution of chloride ions and the coordination of hydrogen peroxide, which is not conducive to the process of oxygen-oxygen bond heterolysis; 2) The sludge system has complex and changeable characteristics, which cannot It is conducive to the occurrence of oxygen-oxygen bond heterocleavage process, so it is difficult to stably produce a sufficient amount of high-valent iron oxide species. The existence of the above problems makes it still difficult for the existing metalloporphyrin-based Fenton system to effectively hydrolyze sludge, and also makes Subsequent resource utilization of sludge is difficult to realize

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