Adsorption of hexavalent chromium from aqueous solutions by bio-chars obtained during biomass pyrolysis

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 19; no. 1; pp. 190 - 196
• Main Authors: Deveci, Hüseyin, Kar, Yakup
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.01.2013; 한국공업화학회
• Subjects: Activated carbon; Adsorbents; Adsorption; Aqueous solutions; Bio-char; Biomass; Chromium; Combustion; Hexavalent chromium; Pyrolysis; Ultrasonic testing; 화학공학; Hexavalent chromium; Pyrolysis; Adsorption; Bio-char
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2012.08.001

In this study, bio-chars were evaluated as a potential adsorbent for the removal of Cr (VI) ions from aqueous solutions. The effects of some important parameters including initial pH (1.5–7), adsorbent dose (0.2–5g/L), contact time (5–900min) and initial Cr (VI) ion concentration (5–75mg/L) were tested on the removal of Cr (VI) ions from aqueous solution in batch experiments. Maximum adsorption capacities of the tested bio-chars under the certain experimental conditions determined as optimal were 3.53mg/g for NCBC, 3.97mg/g for NZCBC and 6.08mg/g for ACBC, respectively. Results of the kinetic and isotherm modeling studies revealed that the adsorption data fitted well with a pseudo-second order and Langmuir model. In among the tested bio-chars, the bio-char (ACBC) was largely equivalent to activated carbon: AC (9.97mg/g) in terms of adsorption capacity. All results indicated that the bio-chars had higher adsorption capacity than some chars and activated carbons reported previously, and also that these bio-chars could be used successfully as low-cost adsorbents for the removal of chromium ions from aqueous solutions under the tested experimental conditions.