Adsorption of Arsenic and Heavy Metals from Solutions by Unmodified Iron-Ore Sludge

• Published in: Applied sciences Vol. 9; no. 4; p. 619
• Main Authors: Nguyen, Khai, Nguyen, Bien, Nguyen, Hai, Nguyen, Ha
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 13.02.2019
• Subjects: Adsorbents; Adsorption; Anthropogenic factors; Arsenic; Bans; Cadmium; Coal mines; Copper ores; Experiments; Fertilizers; Fourier transforms; FTIR spectrometers; Functional groups; heavy metal; Heavy metals; Iron; Iron ores; Laboratories; Manganese; Metals; Mine drainage; Mine wastes; Mining; Nitrates; Red mud; removal; Slime; Sludge; Smelting; Solid wastes; Spectrum analysis; unmodified iron ore sludge; Wastewater; Water treatment; Zinc; Vietnam; Japan
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app9040619

Arsenic and heavy-metal-contaminated environments are a major concern due to their negative impacts on exposed people and ecosystems. In this study, sludge from an iron-ore processing area was used as an adsorbent to remove As, Mn, Zn, Cd, and Pb from aqueous solutions. The adsorption capacity of target adsorbates was investigated in batch experiments of both single- and mixed-metal solutions. The batch studies show that the maximum Langmuir adsorption capacities of the heavy metals onto the adsorbent occurred in the order Pb > As > Cd > Zn > Mn, and ranged from 0.710 mg/g to 1.113 mg/g in the single-metal solutions and from 0.370 mg/g to 1.059 mg/g in the mixed-metal solutions. The results of the kinetic experiments are consistent with pseudo-first-order and pseudo-second-order models, with a slightly better fit to the latter. Adsorption performances indicate that iron-ore sludge can simultaneously adsorb multiple metal ions and is a promising adsorbent for the removal of toxic pollutants from water.