Batch and Continuous Photo-Fenton Oxidation of Reactive-Red Dye from Wastewater

Abstract

This paper aimed to investigate the ability of photo-Fenton technology to remove Reactive Red dye (RR-‎dye) from wastewater using batch and continuous operating modes. The batch mode of photo-Fenton ‎removal of organic content was conducted under the influence of solution pH (3-10), hydrogen peroxide ‎‎(25-100 ppm), irradiation time (20-90 min), ferrous sulfate (5-20 ppm), and temperature (25-60oC). For ‎comparison, the continuous treatment was conducted under the influence of the flow rate of the ‎contaminated solution (10, 20, 30, 40, and 50 mL/min). The results revealed that the treatability of the ‎batch mode was more effective compared to the continuous mode. In the batch process, the organic ‎contaminant was completely removed compared to 82% obtained when the continuous system was ‎performed. The optimization process showed that the optimal values of the operating variables in the ‎case of the batch removal of RR-dye were 3, 78 ppm, 90 min, 20 ppm, and 60oC for pH, hydrogen ‎peroxide, irradiation time, ferrous sulfate, and temperature, respectively. Moreover, the reversion F-value ‎was 21.69, the probability P value was less than 0.001, and the correlation coefficient was (R2=0.9455), ‎which illustrates the significance of the model obtained for the batch process.‎

Keywords

• dyes
• wastewater treatment
• advanced oxidation processes
• central composite design
• optimization