Preparation method for utilizing nano Fe3O4 to modify PVDF micro-filtration membrane and application thereof

Abstract

Nano Fe3O4 particles are loaded on a traditional PVDF membrane material to modify the membrane and improve hydrophily of the membrane. Furthermore, as the Fe3O4 has electrical conductivity, the Fe3O4can serve as an inter-species direct electron transfer conductor in a microbiological treatment process; thus, an inter-species electron transfer efficiency is improved, and a methane yield of microorganisms in an anaerobic bioreactor is improved. In addition, when pollutants is microbiologically treated in the anaerobic bioreactor, a certain amount of organic acid can be generated, and H<+> ionized from organic acid can react with Fe3O4 to generate Fe<2+> and Fe<3+>. The Fe<2+> can promote microorganism growth, the Fe<3+> has oxidability and can oxidize the pollutants, and the Fe<2+> and theFe<3+> both can improve a degrading effect of microorganisms to the pollutants. When the nano Fe3O4 is utilized to modify the PVDF microfiltration membrane, the degrading treatment effect of the microorganisms to chlorophenol matter is improved, chloro groups on the pollutants can be broken away from benzene rings, toxicity of the pollutants is reduced, and biodegradability of the pollutants is improved.

Description

technical field [0001] The invention relates to the field of biological treatment of organic wastewater, in particular to a preparation method of a PVDF microfiltration membrane modified by nanometer Fe3O4 and its application in an anaerobic biological treatment system. Background technique [0002] Anaerobic biological treatment technology is an effective method for treating high-concentration, refractory and organic wastewater. However, because the anaerobic biological treatment system still faces the problems of poor operational stability and low operational efficiency, it is still difficult to apply the anaerobic biological treatment system to the actual high-concentration, refractory, and organic wastewater treatment. The use of anaerobic membrane bioreactor can effectively improve the stability and treatment performance of anaerobic biological treatment system. [0003] Currently commonly used membrane materials are polyvinylidene fluoride (PVDF). PVDF is a semi-cryst...

AI Technical Summary

Problems solved by technology

However, since the casting liquid of PVDF membrane is an organic solution, in the process of using the membrane to filter pollutants, the organic pollutants in the sewage will adhere to the PVDF membrane, thus forming a filter cake layer.

This will lead to a decrease in the permeability of the membrane and affect the treatment effect of the membrane on pollutants.

Especially in the membrane bioreactor, because in the membrane bioreactor, a large amount of EPS will be produced during the microbial treatment process. When filtering, these EPS will adhere to the surface of the membrane, resulting in a decrease in the permeability of the membrane and improving the membrane bioreactor. The osmotic pressure of the membrane can even cause damage to the membrane

[0005] Traditionally applied membrane materials cannot enhance the performance of the anaerobic treatment process on pollutants, and the traditional membrane has strong hydrophobicity, which is easy to form a filter cake layer, resulting in a decrease in the permeability of the membrane and an increase in the osmotic pressure of the membrane.