Effect of pH, ionic strength, and background electrolytes on Cr(VI) and total chromium removal by acorn shell of Quercus crassipes Humb. & Bonpl

• Published in: Environmental monitoring and assessment Vol. 186; no. 10; pp. 6207 - 6221
• Main Authors: Aranda-García, Erick, Morales-Barrera, Liliana, Pineda-Camacho, Gabriela, Cristiani-Urbina, Eliseo
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-10-2014; Springer Nature B.V
• Subjects: Anions; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; Binding sites; Cations; Chromium; Chromium - analysis; Chromium - chemistry; Earth and Environmental Science; Ecology; Ecotoxicology; Electrolytes; Environment; Environmental impact; Environmental Management; Environmental Monitoring; Environmental Restoration and Remediation - methods; Experiments; Heavy metals; Hydrogen-Ion Concentration; Ions; Kinetics; Metals; Models, Chemical; Monitoring/Environmental Analysis; Osmolar Concentration; Particle size; Quercus; Quercus - chemistry; Sodium chloride; Toxicity; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Chromium; pH; Biosorption; Background electrolytes; Ionic strength
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-014-3849-8

The ability of
Quercus crassipes
acorn shells (QCS) to remove Cr(VI) and total chromium from aqueous solutions was investigated as a function of the solution pH, ionic strength, and background electrolytes. It was found that Cr(VI) and total chromium removal by QCS depended strongly on the pH of the solution. Cr(VI) removal rate increased as the solution pH decreased. The optimum pH for total chromium removal varied depending on contact time. NaCl ionic strengths lower than 200 mM did not affect chromium removal. The presence of 20 mM monovalent cations and anions, and of divalent cations, slightly decreased the removal of Cr(VI) and total chromium by QCS; in contrast, divalent anions (SO
4
2−
, PO
4
2−
, CO
3
2−
) significantly affected the removal of Cr(VI) and total chromium. The biosorption kinetics of chromium ions followed the pseudo-second-order model at all solution pH levels, NaCl ionic strengths and background electrolytes tested. Results suggest that QCS may be a potential low-cost biosorbent for the removal of Cr(VI) and total chromium from aqueous solutions containing various impurities.