Method for efficiently degrading azo dye in dye wastewater by using bacteria

Abstract

The invention discloses a method for efficiently degrading azo dye in dye wastewater by using bacteria. The method comprises the following specific steps: (1) inoculating a strain Aeromonas sp.DH-6 into an LB (Luria-Bertani) culture medium, culturing over night in a shaker in the rotation speed of 150-200rmp at 25-35 DEG C, so as to obtain a great amount of bacteria; (2) inoculating the over-night culture which is 2-8% in inoculation amount into the dye wastewater containing azo dye, and standing to culture and decolor, wherein the decoloring pH value is 3.0-7.0, the temperature is 5-45 DEG C, and the decoloring culture time is more than 4 hours. The method disclosed by the invention is still high in decoloring rate for methyl orange under acid conditions at relatively high temperature (about 40 DEG C). Besides, no remarkable influence is caused by most meal ions in coloring, the decoloring rate can be still approximate to 90% when 1000mg / L of the dye is cultured for 48 hours by using the bacteria, and thus the decoloring effect is relatively good. Therefore, compared with a conventional method, the bacterium DH-6 can be used for more efficiently degrading the azo dye with low energy consumption, and is higher in environment applicability, free of secondary pollution to the environment, and wider in research value and application prospect.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a method for efficiently degrading azo dyes in dye wastewater by using bacteria. Background technique [0002] Azo dyes are the most produced and used dyes, and the biotoxicity of the dye itself or its degradation products is relatively high. Therefore, most researches on dye degradation at home and abroad focus on the degradation of azo dyes. The degradation methods involve Various physical and chemical methods such as iron-carbon reduction, Fenton oxidation, ozone oxidation and photocatalytic oxidation, as well as biological methods such as aerobic, facultative and anaerobic microbial degradation. Among them, the physical and chemical treatment technology has the defects of high cost, low efficiency, easy to produce secondary pollution and difficult to treat the sediment, which greatly hinders its wide application, while the biological treatment method has low treatmen...

AI Technical Summary

Problems solved by technology

[0004] The current technical problems in the degradation of azo dyes mainly include: traditional physical and chemical treatment methods, high cost, easy to cause secondary pollution to the environment, complex equipment operation and other defects; fungal growth is slow, and a large number of strains need to be inoculated to obtain larger organisms. The amount of degradation is not high, and most of the fungal degradation dyes belong to secondary metabolism, and the degradation-related enzymes need to be cultivated for a long time to produce, and the yield is also very low; the bacterial environment adaptability is poor, the degradation dye category is single, and the degradation effect of existing strains passable etc.