Enhanced methylene blue degradation and miniralization through activated persulfate coupled with magnetic field

In this work, for the first time, the effectiveness of the degradation and mineralization process of methylene blue) MB) was investigated using activated persulfate (PS) with a magnetic field. The effect of various operating parameters, including pH, PS (5–20 mg/L), intensity of the magnetic field (1–4 A), initial concentration of methylene blue dye (25–100 mg/L), and contact time (30–120 min), was evaluated. Process optimization was conducted via the Taguchi model, and the optimal values of these factors were found to be pH = 5, PS = 10 mg/L, MFs = 4 A, reaction time = 30 min, and the initial concentration of methylene blue dye = 50 mg/L. Under optimal conditions, the methylene blue removal efficiency and TOC destruction efficiency reached 91.8% and 88%, respectively. The kinetics of the process followed pseudo-second order (R² = 0.9723). According to the promising results of the research, the efficiency of dye purification using a magnetic field has increased by about three times compared to the state without this factor. It can be suggested that this system be used as a wastewater treatment process for the textile industry to reduce the toxicity of wastewater and total organic carbon (TOC).