Discoloration and mineralization of a textile azo dye using a hybrid UV/O3/SBR process

Abstract

Most synthetic dyes are toxic and hardly biodegradable compounds that enter the environment mainly through the discharged of non-treated textile industry effluents. The present study investigated the removal of the textile monoazo dye Reactive Red 198 (RR-198) from aqueous solutions using the ultraviolet light and ozonation alone and in combination (i.e., UV/O3) followed by a Sequencing Batch Reactor (SBR). The pH (5 ≤ pH ≤ 9) and dye initial concentration (50–300 mg/L) parameters were optimized in the ozonation process at reaction time of 0–60 min. Then, TOC removal and dye discoloration percentage was compared with the O3, UV and O3/UV processes. In order to compare the performance of the SBR in dye discoloration of RR-198 and TOC removal, four types of effluent, including Raw dye, O3-pretreated dye, UV-treated dye and UV/O3-pretreated dye were separately treated in the SBR system. In the ozonation process, by increasing the pH and reducing the initial dye concentration increased the discoloration percentage. The highest dye discoloration percentage and TOC removal obtained in the hybrid UV/O3/SBR process. Combining biological systems and Advanced Oxidation Processes is an appropriate option for the decomposition of resistant pollutants and increasing the biodegradability of these compounds and is applicable in the water and wastewater industry.

Optimization of a novel hybrid photo-ozonation peroxymonosulfate process for degradation of Acid Black ATT dye in aqueous environment

“…The O 3 /UV system enhanced the decomposition of ozone molecules and produced more free radicals. [43] Therefore, the highest removal efficiency occurs with photo-oxidation (O 3 /UV) processes, followed by O 3 and photolysis (UV) systems. The results also showed that the O 3 and UV processes were synergistic with each other, reaching a maximum at a reaction time of 20 minutes, equivalent to 100%.…”

Optimization of a novel hybrid photo-ozonation peroxymonosulfate process for degradation of Acid Black ATT dye in aqueous environment

“…[45] The results obtained by Mahdizadeh et al to remove textile monoazo dye Reactive Red 198 and TOC using the hybrid UV/O 3 /Sequencing Batch Reactor (SBR) system showed that the highest discoloration percentage (97.5%) and TOC removal (86.3%) was found. [43] Fig7. The effect of the time of the reaction efficiency of the UV/O 3 /PMS process.…”

The Effect of Modifying Canadian Goldenrod (Solidago canadensis) Biomass with Ammonia and Epichlorohydrin on the Sorption Efficiency of Anionic Dyes from Water Solutions

“…Post-production wastewater from the textile, tanning or paper industries may contain significant amounts of dyes. Industrial dyes are usually of synthetic origin, feature a complicated chemical structure, and are highly stable, which makes them sparingly biodegradable [ 1 ]. Due to the high color intensity and ease of application, anionic reactive dyes are most often used in dyeing processes [ 2 ].…”