Diatomaceous earth incorporated floating magnetic beads for oil removal on water
Document Type
Article
Publication Date
2-1-2022
Abstract
Water contamination by oil spills causes severe damage to the environment and human health. Oil adsorbents should be buoyant, effective oil-contact, and regenerable. In this study, diatomaceous-earth (DE)-incorporated magnetic alginate (Alg)-based beads, chemically modified to include phthalic or maleic anhydride (denoted as Alg/DE/Fe3O4 PA and Alg/DE/Fe3O4 -MA), were developed. Internal cavities, formed by cavity-forming agents, made them buoyant. The beads were buoyant and magnetically responsive for 30 days. Maximum oil adsorption capacities of Alg/DE/Fe3O4 -PA and Alg/DE/Fe3O4 MA were 29.7 and 21.0 times their weights, respectively. The pseudo-second order kinetics model (R-2 similar to 0.999, ARE <= 1.088, and chi(2) <= 0.041) and Freundlich isotherm model (R-2 similar to 0.999, ARE <= 0.1, and chi(2) <= 3.37x 10(-3)) were used to determine these values. Both beads were magnetically regenerable for up to 20 cycles. DE pores improved oil adsorption capacity by facilitating intra-bead diffusion of surface adsorbed oil. This was confirmed by micro-structural characterization using surface micrographs, elemental distribution, porosity, thermal stability, crystalline phases, molecular vibrational behavior, and magnetic properties. Scanning electron microscopy and X-ray diffractometry analyses revealed spherical beads with well-distributed Fe3O4 spinel on the surfaces. The two adsorbent beads satisfied the criteria for oil-removal from water: buoyancy, high affinity towards various oil types, and magnetic re-collectability. (C) 2021 The Author(s). Published by Elsevier B.V.
Keywords
Alginate, Diatomaceous earth, Magnetic separation, Oil spill, Buoyancy, Water purification
Divisions
nanotechnology
Funders
None
Publication Title
Environmental Technology & Innovation
Volume
25
Publisher
Elsevier
Publisher Location
RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS