Biosorption of chromium (Cr(III)/Cr(VI)) on the residual microalga Nannochloris oculata after lipid extraction for biodiesel production.
In order to increase the economic feasibility of biodiesel production from microalgae, the residual biomass after biodiesel production can be utilized as biosorbent for heavy metal removal. In this study, biosorption of chromium by residual Nannochloris oculata after lipid extraction was investigated. Increased surface area of N. oculata was observed after lipid extraction. Cr(III) removal increased as the pH increased from 2 to 6, while Cr(VI) removal was highest at pH 2 and it decreased with the increase in pH. Cr(VI) was reduced to Cr(III) in the presence of biomass under acidic conditions; X-ray photoelectron spectroscopy revealed that the converted Cr(III) was bound to the biomass. Chromium removal was significantly enhanced at high chromium concentrations, which indicates that surface reactions may occur at high chromium/biomass ratios. FTIR study indicated that phosphate and carboxyl functional groups of the biomass were mainly responsible for chromium binding.
Advanced Biomass R&D Center, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Eun Jung
EJ
Kim
Soojung
S
Park
Hye-Jin
HJ
Hong
Yoon-E
YE
Choi
Ji-Won
JW
Yang
D000327:Adsorption; D001673:Biodegradation, Environmental; D056804:Biofuels / Q000382:microbiology*; D018533:Biomass; D002857:Chromium / Q000302:isolation & purification*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008055:Lipids / Q000302:isolation & purification*; D058086:Microalgae / Q000378:metabolism*; D056951:Photoelectron Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors
D056804:Biofuels; D008055:Lipids; D002857:Chromium