Evaluation of oilfield-produced water treated with a prepared magnetic inorganic polymer: Poly(silicate aluminum)/magnetite

In this study, novel coagulant poly(silicate aluminum)/Fe3O4 nanoparticles (PFeNPs) were prepared via magnetic iron oxide nanoparticles (FeNPs) modified by poly(silicate aluminum) (PSA). The physiochemical properties of the PFeNPs were investigated with Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and -potential metric analysis. The effect of the aging time on the Al distribution of the PFeNPs was analyzed by the Al-Ferron timed complex colorimetric method. Oilfield-produced water was used for the assessment of the coagulation performances. The fractal dimensions, formation, breakage, and regrowth of the flocs were studied in turn. The experimental results show that the PFeNPs exhibited a porous layer of a net structure, and the PSA grafted onto the PFeNPs via SiOFe enhanced the positive charge of the FeNPs. Meanwhile, the coagulation performance of the PFeNPs on total organic carbon, the turbidity, and the calcium removal were beyond 98%. In addition, the moisture content of the flocs derived from the PFeNPs was 68.7% (it is normally>98%). We found that the compactness of the flocs derived from the PFeNPs was far greater than those of PSA. This will provide new sight into the preparation of magnetic single-phase inorganic polymer coagulants. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45735.