A bench study was carried out to characterize the kinetics of two plant growth promoting rhizobacteria (PGPR) Azotobacter chroococcum and Bacillus megaterium to adsorb heavy metals from solution. Adsorption of Pb²⁺ and Cd²⁺ by bacterial cells was processed quickly with an equilibration achieved within 5 min. The adsorptions were fitted well with Freundlich and Langmuir isotherm models. The comparison of isotherm parameters indicated that A. chroococcum had a stronger capacity to bind metal ions than B. megaterium, with an average increase of 59.8% for Pb²⁺ and 75.6% for Cd²⁺, respectively. Both bacteria had a stronger affinity to Pb²⁺ than Cd²⁺ since Pb²⁺ was more easily bound with the phosphoryl groups on the cell surface than Cd²⁺. This demonstrated that the presence of bacteria in the rhizosphere may result in the reduction of mobile ions in soil solution. Copyright © 2009 Elsevier Ltd. All rights reserved.
CitationWu, S. C., Peng, X. L., Cheung, K. C., Liu, S. L., & Wong, M. H. (2009). Adsorption kinetics of Pb and Cd by two plant growth promoting rhizobacteria. Bioresource Technology, 100(20), 4559-4563. doi: 10.1016/j.biortech.2009.04.037
- Heavy metals ion
- Medal binding capacity