Adsorption of heavy metals ions and oil products by magnetic composite sorbents based on waste of wood fiber

Abstract

Copyright © 2019 American Scientific Publishers. All rights reserved. Magnetic composite sorbents (MCS) based on wood fibre waste (WFW) produced by MDF and synthetic magnetite (Fe 3 O 4 ) were obtained in the framework of the presented work. The process of obtaining MCS consisted in deposition of Fe 3 O 4 nanoparticles on the surface of WFW with ammonia water from a solution containing a mixture of trivalent and bivalent iron chlorides. Physicochemical and adsorption properties of composite materials are investigated. It is established that the effect of ultrasonic vibrations during Fe 3 O 4 deposition increases the specific surface area in comparison with the materials obtained without the imposition of ultrasound. The main components of MCS are oxygen, carbon, nitrogen and iron according to the elemental analysis. The presence of a small amount of calcium, magnesium, silicon and iron in the original fiber is explained by the use of binding components in the production, as well as the adhesion of mechanical particles. There is a noticeable increase in the mass fraction of iron associated with Fe3O4 deposition after modification. Experiments on purification of aqueous solutions using MCS have shown that the average degree of purification from ions of heavy metals and petroleum products varies from 79 to 86% depending on the content of Fe 3 O 4 in the composite. Deposition on the surface of WFW Fe 3 O 4 allowed to increase the efficiency of purification of aqueous solutions from heavy metal ions by more than 20%. It is revealed that at increase of iron content in the composition of the composite from 1 to 25% the efficiency of purification from dissolved petroleum products is reduced by 16%. It is established that MCS-1 and MCS-5 sorption materials possess the best adsorption properties. The subsequent increase in the content of Fe 3 O 4 in the composition of composites does not lead to a significant improvement in the adsorption properties, leads to an increase in ash content, worsens the strength and reduces the performance of purification systems in dynamic conditions due to the increase in the pour density of composite materials.