Sludge pretreatment method based on sulfo-porphyrin iron catalyst Fenton-like system

Abstract

The invention discloses a sludge pretreatment method based on a sulfo-porphyrin iron catalyst Fenton-like system, which comprises the following steps: mixing a sulfo-porphyrin iron catalyst, methanol and a hydrogen peroxide solution, stirring, mixing the obtained mixed solution with sludge, and carrying out hydrolysis treatment to complete the pretreatment of the sludge. According to the sludge pretreatment method based on the sulfo-porphyrin iron catalyst Fenton-like system, the sulfo-porphyrin iron catalyst, methanol and the hydrogen peroxide solution are mixed and stirred to generate the mixed solution containing high-valence iron species, the mixed solution is further mixed with sludge, the sludge is effectively treated by utilizing the high-valence iron species, and the sludge treatment efficiency is improved. The method has the advantages of low catalyst and oxidant consumption, mild reaction conditions, high treatment efficiency, good treatment effect, good adaptability and the like, has very important significance for improving the subsequent resource utilization effect of the sludge, and is high in use value and good in 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 porphyrin iron catalyst Fenton-like system. Background technique [0002] The Fenton system is one of the typical advanced oxidation technologies that have been widely proven to promote sludge hydrolysis. In this system, ferrous ions activate hydrogen peroxide to generate hydroxyl radicals, and through this strong oxidizing free radicals and Electron exchange occurs in the extracellular polymer, thereby achieving rapid decomposition of the extracellular polymer. The oxidation potential of hydroxyl radicals is 2.7-2.8V, which is much higher than that of hydrogen peroxide (1.76 V), and it is the core substance for 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 radicals and iron ions; 2) Iro...

AI Technical Summary

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

Images