Photocatalytic activation of peroxymonosulfate by MOF-5@Fe3O4 in the removal of acid blue 113 from polluted water

Acid Blue 113 (AB113), due to its azo group (-N = N-) and benzene structure, can pose several problems for wastewater treatment processes and aquatic ecosystems. Therefore, in the present study, magnetic nanoparticles combined with an organic-inorganic framework (MOF-5@Fe 3 O 4 ) were synthesized to act as a photocatalytic activating agent for peroxymonosulfate (PMS) in the degradation of AB113. The impact of operational parameters on the performance of the MOF-5@Fe 3 O 4 /visible/PMS process was evaluated. Complete AB113 degradation and 94.77 % COD removal were achieved at pH 5, catalyst mass of 0.8 g/L, dye concentration of 25 mg/L, and PMS concentration of 4 mM. A total organic carbon (TOC) removal percentage of 88.91 % and a BOD 5 /TOC ratio of 1.21 indicated that the process converted the carbon structure of AB113 to CO 2 . The lethal concentration 50 % (LC 50 ) and toxic units (TU) values were investigated through the growth of Daphnia magna . After 48 h, the LC 50 of the treated solution was 8.41 times that of the raw solution. The TU value decreased from 8.85 to 1.75 in the presence of PMS and the catalyst in the dye treatment process. The photocatalyst demonstrated stability, maintaining over 80 % efficiency across six consecutive reaction cycles. Using different scavengers, the reactive species involved in the PMS activation process were evaluated. The energy consumption for the treatment of 25 mg/L dye by the present process was 40 kWh/m 3 . Finally, it can be said that this process has successfully eliminated color pollutants from textile industry wastewater and brought them to standard levels.