Clean application of magnetic biomaterial for the removal of As (III) from water

• Published in: Environmental science and pollution research international Vol. 25; no. 30; pp. 30348 - 30365
• Main Authors: Pholosi, Agnes, Naidoo, Bobby E., Ofomaja, Augustine E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2018; Springer Nature B.V
• Subjects: Adsorption; Anion exchanging; Anions; Aquatic Pollution; Arsenic - chemistry; Atmospheric Protection/Air Quality Control/Air Pollution; Biomass; Biomaterials; Biomedical materials; Data processing; Earth and Environmental Science; Ecotoxicology; Electron microscopes; Environment; Environmental Chemistry; Environmental Health; Environmental science; Ferrosoferric Oxide - chemistry; Free energy; Humic acids; Hydrogen-Ion Concentration; Ionic strength; Iron oxides; Kinetics; Leaching; Magnetics; Magnetite; pH effects; Pine; Pinus - chemistry; Plant Structures; Research Article; Scanning electron microscopy; Waste Water Technology; Water - chemistry; Water Management; Water Pollutants, Chemical - chemistry; Water Pollution Control; Water Purification - methods; Magnetic adsorbent; Anion-exchange coefficient; Mean free energy; Arsenic (III); Adsorption mechanism; Anion-adsorbate interaction
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-018-2990-2

Magnetite-coated pine cone biomass was successfully synthesized, characterized, and its interaction with As (III) in water evaluated in order to apply it as an efficient adsorbent. Transmission electron microscope, scanning electron microscope, and imaging studies revealed that spherical magnetite particles were evenly distributed over the pine cone surface. Adsorption studies showed that the optimum pH of As (III) adsorption was 8 and that Fe (III) leaching was negligible at this pH. The optimum Fe 3 O 4 :pine cone ratio for As (III) removal was 2.0 g Fe 3 O 4 :1.5 g pine cone with adsorption capacity of 13.86 mg/g. The pseudo-second-order model best fitted the kinetic data with activation energy of adsorption was calculated to be 23.78 kJ/mol. The Langmuir isotherm described the equilibrium data best while the values of Dubinin–Radushkevich mean free energy suggests anion-exchange process. Increasing ionic strength slightly increased As (III) capacity of MNP-PCP from 13.86 to 17.82 mg/g at optimum solution pH of 8, but As (III) adsorption reduced by PO 4 3 − anions and humic acid due to competition. Adsorption mechanism was confirmed with evidence from FTIR, XPS, pH PZC , and NO 3 − replacement by As (III) adsorption onto the NO 3 − -loaded composite.