Suspended and Coated Iron Waste for Photo-Fenton-Like Degradation of Industrial Effluents under Neutral Condition

Abstract

The iron waste collected from steel workshop was evaluated as a catalyst in heterogenous photo-Fenton like process. The analyses such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were carried out to assess the morphology, chemical structure and chemical composition of the iron waste. The degradation efficiency of methylene blue (MB) went up from 81.4% in dark to 90.4% in light in the case of iron loading of 0.5 g/100 mL, persulfate (PS) concentration of 0.1 mM, MB concentration of 10 mg/L and pH 7. The uppermost degradation efficiency of MB was accomplished at pH 3 and the raising of PS concentration above 0.25 mM reduced the removal efficacy of MB. The degradation percentage of MB declined in the case of iron loading higher than 1.0 g/100 mL. The degradation rates of MB decreased with the rise of initial MB concentration. The degradation efficiencies of MB were 68.8%, 67.3%, 64.3%, 63% and 60% in five consecutive runs and the degradation efficiencies of pharmaceutical wastewater were 36.55%, 35.69%, 34.24%, 33.4% and 32% using the iron coated plates. The degradation ratios of agrochemical wastewater were 40.76%, 38.6%, 37.5%, 36.1% and 34.98%, whereas they were 23.7%, 22.35%, 22.03%, 21.23% and 20.03% in the case of petrochemical wastewater in five successive runs using the immobilized plates.