Effect of varying deposition conditions of magnetite on sawdust on the physiochemical properties of the prepared composites

Abstract

This work reports a novel study for deposition of magnetite (Mag) on olive wood sawdust (OW) by the coprecipitation-hydrothermal method under dominating deposition factors including deposition temperature of magnetite by OW, agitation time, magnetite deposition in presence/absence of OW, magnetite/OW mass ratio, pyrolysis of final composites. The composites were characterized by IR, XRD, TGA, surface area (by N2 and methylene blue adsorption test) and lead uptake The effect of experimental factors on physicochemical properties were addressed. Principal component analysis (PCA) was found effective for understanding the differences among composites. It was found that magnetite deposition has relatively increased the stability of OW against degradation. XRD and IR data showed that not only various deposition conditions caused deposition of various amounts of iron oxides and magnetite on wood surface; but also the amount of deposited iron oxides exceeded that of magnetite. Pb ions adsorption was significantly affected by the deposition conditions in which deposition time was the most dominant among the tested factors as 5 h stirring (at 50 °C) achieved the best lead uptake. In general, deposition of magnetite by OW reduced porosity of composites. The prepared composites were effective for Pb removal with capacitates 22–49 mg g−1 at pH 7.0. Not all physicochemical parameters were effective for composites grouping. Surface areas and Pb uptake were most responsive for experimental conditions.