Novel Fenton-like process (pre-magnetized Fe0/H2O2) for efficient degradation of organic pollutants

A new modified Fenton-like process (pre-magnetization Fe 0 /H 2 O 2 ) was employed to enhance the degradation of organic pollutants and reduce reagents dosage, using azo dye of tartrazine as the model. Compared with Fe 0 /H 2 O 2 process, pre-magnetization Fe 0 /H 2 O 2 process could have 1.3–11.2 folds enhancement in the degradation rate of tartrazine at different Fe 0 dosages (0.5–4   mmol), initial pH levels (2–6.5) and H 2 O 2 dosages (0.25–2   mmol) owing to the change of Fe 0 characteristics after pre-magnetization. The contact angle of pre-magnetization Fe 0 decreased from 58.4° to 19.8° enhancing the hydrophilicity and BET increased from 0.15   m 2 /g to 1.94   m 2 /g, which improved the corrosion of Fe 0 and accelerated the generation of Fe 2+ . Similar to the case of tartrazine, pre-magnetization Fe 0 /H 2 O 2 process had remarkable improvement on many refractory contaminants. The degradation rate constant of methyl orange, orange, methylene blue, 2,4-dichlorophenol (2,4-DCP), acetylsalicylic acid, phenol and tetracycline by pre-magnetization Fe 0 /H 2 O 2 process was 5.2, 21.3, 9.2, 5.6, 12.3, 9.5 and 3 folds of that by Fe 0 /H 2 O 2 process, respectively. The “magnetic memory” of pre-magnetization Fe 0 could last 24   h which was suitable for off-site application, and the lost some or all “magnetic memory” could be recovered after second pre-magnetization. Pre-magnetization Fe 0 /H 2 O 2 is a more promising and highly efficient Fenton process since it does not require any change of the present water and wastewater treatment process , and does not need an extra energy source and complex equipment but can widen pH range and save more than 75% Fe 0 and H 2 O 2 dosages.