Novel reusable renewable resource-based iron oxides nanocomposites for removal and recovery of phosphate from contaminated waters: Removal of phosphate from contaminated waters using reusable renewable resource-based nanocomposites

Water pollution and purification are significant issues currently facing the world. Phosphorous is one of the pollutants which degrades water quality and is a cause of concern for eutrophication of water. This paper discusses the synthesis of a novel renewable resource-based nanocomposite, its use in phosphorus remediation, and its regeneration. The nanocomposite is synthesized from waste pine wood chips with stepwise chemical treatment. The synthetic method is environmental friendly and economically viable. Harmful chemicals are not used in the synthesis of the nanocomposite, which represents a significant shift from existing technologies. These nanocomposites are found to be useful for the removal of phosphate from contaminated waters, mainly agricultural wastes, mine drainage, and seawater. The superiority of using nanocomposites for adsorption is mainly associated with the positive charge as well as the presence of iron oxide nanoparticles on the surface of the media. Scanning electron microscopy and X-ray photoelectron spectroscopy were performed to determine the size and the elements present on the surface of the nanocomposite. Kinetic studies and adsorption isotherm were conducted which helped in proposing a mechanism for adsorption of phosphate on the media. Results indicate that phosphorus levels can be brought down from 1000 parts per billion to at least 10 parts per billion from stock solutions. The phosphorus could also be desorbed and the media regenerated for reuse at least 100 times without loss of phosphorus removal efficiency.