In situ sequentially generation of acid and ferrous ions for environmental remediation

Novel heterogeneous Fenton composite materials were developed by grafting acid precursors and nano zero-valent iron particles on an acid leached diatomite, which can sequentially generate acid and ferrous ions in situ. The results show that the composite materials can potentially solve two of the biggest obstacles, which prevent the conventional Fenton reaction from being widely and practically adopted, namely: the continuous feed of ferrous ions and the maintenance of the optimum acidic pH condition during the reaction. In this study, samples were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Thermogravimetric analysis and micro organic analysis. The novel materials’ degradation capacities for bisphenol A (BPA) were evaluated and optimized. This material can be easily applied to treat wastewater via Fenton-like reaction without changing pH or adding ferrous ions. The relationships between BPA removal efficiency, the amount of grafted organosilane acid precursor and doped nZVI particles on the composite materials were investigated. It is evident from the results that the novel composite materials afford highly effective removal of BPA from water at 250 mg/g. The work thus demonstrates that the novel materials could potentially be utilized for efficient remediation of recalcitrant organic compounds from the environment.