Influence of aniline and antimony on micro-oxygen hydrolysis and acidification processes in printing and dyeing wastewater treatment

Abstract

This experiment studied the degradation characteristics of aniline and antimony in printing and dyeing wastewater by the micro-oxygen hydrolysis acidification process and its influence on the removal of COD and ammonia nitrogen. Firstly, the study optimized the control factors of pH、dissolved oxygen (DO)、sludge concentration on the removal efficiency of COD and ammonia nitrogen in hydrolysis and acidification section. It is recommended that pH can be maintained at 6.5; low dissolved oxygen (0-0.5 mg/L) would help the conversion of nitrogen substances for subsequent treatment, the optimal treatment temperature was found to be 25℃, furthermore, it is recommended to control the sludge concentration at 4 mg/L during operation. Secondly, the impact of aniline and antimony on COD and nitrogen removal was explored. It was found that when the aniline concentration increased from 0.4 mg/L to 5.4 mg/L, the effluent COD concentration increased, with a rate of 96.5%, indicating that aniline was toxic to anaerobic sludge and significantly inhibited the COD degradation; while when the antimony concentration increased from 0.05 mg/L to 2.05 mg/L, the COD removal rate was only 2.9%, which was far lower than the COD removal rate of water samples without adding antimony. The decrease of anaerobic sludge concentration from 5.58 g/L to 3.44 g/L indicated that aniline and antimony have a strong inhibitory effect on the activity of anaerobic bacteria, and reversely affect the COD removal.

Effect of Enhanced Hydrolytic Acidification Process on the Treatment of Azo Dye Wastewater

“…This is speculated to be due to the presence of a fructose co-matrix, which further degrades the intermediate products of azo dyes, aromatic amines, and amides. Azo dye mineralization is more complete [22,23].…”