Study on Mechanisms of Cu2+ Biosorption by Aquatic Plant Hydrilla verticillata (L.f.) Royle
黑藻吸附Cu2+机制研究

Biosorption is a kind of effective and economical method to get rid of heavy metals from polluted waters. The isotherm adsorption of Cu2+ by Hydrilla verticillata (L.f.) royle was investigated. In addition, through testing cation concentrations before and after the isotherm adsorption as well as the effects of pH and blocking of functional groups on Cu2+ adsorption abilities, mechanisms of Cu2+ biosorption were discussed from several aspects such as electrostatic adsorption, ion exchange, complexation. Results indicated that biosorption equilibrium data were best described by Langmuir isotherm model followed by Freundlich model and Double Langmuir model. This adsorbent can remove about 70% of Cu2+ and has the maximum adsorption capacity of 42.86 mg/g for Cu2+. Moreover, electrostatic adsorption, ion exchange and functional groups are supposed to responsible for biosorption of Cu2+. Through blocking functional groups combined with the analysis of FTIR, carboxyl and amino groups are confirmed to be the main active groups which were involved in the biosorption of Cu2+. In conclusion, dried H. verticillata can provide a promising technology for eliminating copper from industrial effluents.