Significant enhancement in treatment of salty wastewater by pre-magnetization Fe0/H2O2 process

Nowadays, Fenton (Fe 2+ /H 2 O 2 ) process is increasingly applied to wastewater treatment, however, the treatment efficiency would be inhibited largely when treated salty wastewater. To overcome this limitation, pre-magnetization (pre-magn-Fe 0 )/H 2 O 2 process was investigated to treat salty wastewater, which could enhance the degradation rate of organic pollutants (1.2–171.2 folds enhancement) and reduce reagents dosage (save 75% H 2 O 2 ) in salty system compared with Fe 0 /H 2 O 2 process, using Orange G as the target pollutant and Na 2 SO 4 as the model salty system. The characterizations by SEM, XRD and XPS and the intensity of DMPO–OH adduct signals in different processes confirmed this enhancement attributed to the increase of corrosion of Fe 0 inducing fast catalysis of H 2 O 2 and generation of hydroxyl radicals. Pre-magn-Fe 0 /H 2 O 2 process could also have 5.9, 26.4 and 93.7 folds enhancement in NaCl, NaNO 3 and Na 2 HPO 4 salty system, respectively. Meanwhile, pre-magn-Fe 0 /H 2 O 2 process could keep close performance in Na 2 SO 4 and NaCl salty systems and have better performance in NaNO 3 and Na 2 HPO 4 salty systems than Fenton process. Pre-magn-Fe 0 /H 2 O 2 process also had remarkable improvement (1.1–5.3 folds) on the removal of many refractory contaminants in salty system. Furthermore, it could also keep good performance in real reverse osmosis concentrated wastewater and petrochemical wastewater. Therefore, pre-magn-Fe 0 /H 2 O 2 process is a more cost-effective process to treat salty wastewater, which could have not only improved performance than conventional system and Fe 0 /H 2 O 2 process, but also good performance as Fenton process.