Open AccessThis article is
- freely available
Removal of Mercury by Foam Fractionation Using Surfactin, a Biosurfactant
Department of Life Science, National Chung Cheng University, 168 University Road, Minhsiung, Chiayi 621, Taiwan
Department of Biotechnology, National Kaohsiung Normal University, No. 62, Shenjhong Road, Yanchao Township, Kaohsiung County 82444, Taiwan
Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Minhsiung, Chiayi 621, Taiwan
Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
Departments of Urology, Mackay Memorial Hospital, 92, Section 2 Chung San North Road, Taipei 10449, Taiwan
Department of Physics, National Chung Cheng University, 168 University Road, Minhsiung, Chiayi 621, Taiwan
These authors contributed equally to this work.
* Author to whom correspondence should be addressed.
Received: 11 October 2011; in revised form: 4 November 2011 / Accepted: 9 November 2011 / Published: 21 November 2011
Abstract: The separation of mercury ions from artificially contaminated water by the foam fractionation process using a biosurfactant (surfactin) and chemical surfactants (SDS and Tween-80) was investigated in this study. Parameters such as surfactant and mercury concentration, pH, foam volume, and digestion time were varied and their effects on the efficiency of mercury removal were investigated. The recovery efficiency of mercury ions was highly sensitive to the concentration of the surfactant. The highest mercury ion recovery by surfactin was obtained using a surfactin concentration of 10 × CMC, while recovery using SDS required < 10 × CMC and Tween-80 >10 × CMC. However, the enrichment of mercury ions in the foam was superior with surfactin, the mercury enrichment value corresponding to the highest metal recovery (10.4%) by surfactin being 1.53. Dilute solutions (2-mg L−1 Hg2+) resulted in better separation (36.4%), while concentrated solutions (100 mg L−1) enabled only a 2.3% recovery using surfactin. An increase in the digestion time of the metal solution with surfactin yielded better separation as compared with a freshly-prepared solution, and an increase in the airflow rate increased bubble production, resulting in higher metal recovery but low enrichment. Basic solutions yielded higher mercury separation as compared with acidic solutions due to the precipitation of surfactin under acidic conditions.
Keywords: mercury removal; foam fractionation; biosurfactant; Surfactin
Citations to this Article
Cite This Article
MDPI and ACS Style
Chen, H.-R.; Chen, C.-C.; Reddy, A.S.; Chen, C.-Y.; Li, W.R.; Tseng, M.-J.; Liu, H.-T.; Pan, W.; Maity, J.P.; Atla, S.B. Removal of Mercury by Foam Fractionation Using Surfactin, a Biosurfactant. Int. J. Mol. Sci. 2011, 12, 8245-8258.
Chen H-R, Chen C-C, Reddy AS, Chen C-Y, Li WR, Tseng M-J, Liu H-T, Pan W, Maity JP, Atla SB. Removal of Mercury by Foam Fractionation Using Surfactin, a Biosurfactant. International Journal of Molecular Sciences. 2011; 12(11):8245-8258.
Chen, Hau-Ren; Chen, Chien-Cheng; Reddy, A. Satyanarayana; Chen, Chien-Yen; Li, Wun Rong; Tseng, Min-Jen; Liu, Hung-Tsan; Pan, Wei; Maity, Jyoti Prakash; Atla, Shashi B. 2011. "Removal of Mercury by Foam Fractionation Using Surfactin, a Biosurfactant." Int. J. Mol. Sci. 12, no. 11: 8245-8258.