Advanced Biomass R&D Center, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Bioresour Technol. 2011 Dec;102(24):11155-60. doi: 10.1016/j.biortech.2011.09.107. Epub 2011 Oct 1.
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.
为了提高微藻生物柴油生产的经济可行性，可以利用生物柴油生产后的剩余生物质作为重金属去除的生物吸附剂。本研究考察了脂类提取后的微拟球藻对铬的吸附作用。脂类提取后，微拟球藻的比表面积增加。随着 pH 值从 2 增加到 6，Cr(III)的去除率增加，而 Cr(VI)的去除率在 pH 值为 2 时最高，随着 pH 值的增加而降低。在酸性条件下，生物质存在下将 Cr(VI)还原为 Cr(III)；X 射线光电子能谱表明，转化的 Cr(III)与生物质结合。在高铬浓度下，铬的去除率显著提高，这表明表面反应可能发生在高铬/生物质比下。傅里叶变换红外光谱研究表明，生物质中的磷酸根和羧基官能团主要负责铬的结合。
