TECHNICAL PAPER
Ozonation for Decolorization and Biodegradability Enhancement of Synthetic Wastewater Containing Reactive Black 5 and Reactive Orange 16
2023 Volume 59 Issue 3 Pages 33-37
Details
2023 Volume 59 Issue 3 Pages 33-37
Synthetic wastewater containing 32 mg/L Reactive Black 5 （RB5） or 32 mg/L Reactive Orange 16 （RO16） was treated using ozonation in a 2 L batch reactor. The color units of wastewater containing RB5 and RO16 were reduced respectively from 835 to 50 and from 2780 to 750 after 8 min. Each was reduced to less than 50 after 15 min ozonation （6.3 g－O3/m3, 4 L/min）. The first-order decolorization constant was 0.35 min－1 for RB5 and 0.47 min－1 for RO16. Biodegradation tests using activated sludge microorganisms showed increased biochemical oxygen demand of the wastewater by ozonation. The total organic matter （TOC） concentration of RB5-containing wastewater was decreased from 8.9 mg/L to 8.4 mg/L by biodegradation alone, 5.8 mg/L by ozonation alone, and 3.3 mg/L by ozonation followed by biodegradation. The TOC concentration of RO16-containing wastewater was decreased from 13.9 mg/L to 12.9 mg/L by biodegradation alone, 7.1 mg/L by ozonation alone, and 4.0 mg/L by ozonation followed by biodegradation. These results suggest that installing the ozonation process as a pretreatment for conventional bioprocesses can achieve enhanced and robust dye treatment.
