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The study of binary biosorption of Pb(II) and Cu(II) was performed by pine nuts shell. Results were compared with the single biosorption of Pb(II) and the single biosorption of the Cu(II). Experiments were performed in batch stirred and in a continuous system. The presence of lead caused a slightly decrease of the copper biosorption yield and can be related to the copper equilibrium uptake. This antagonistic action can be related to competition phenomena between metal ions in solution for active sites presented on the pine nut shell. The affinity of Pb(II) for pine nuts shell was higher than that of Cu(II). The extended Langmuir model and the extended Sips model were used to fit experimental data from binary experiments carried out in batch stirred system. Both models correctly fitted biosorption equilibrium data in range of concentrations studied. Differences obtained by both models were small, however, extended Sips model reproduced lightly better experimental results tan the extended Langmuir one. In the binary system, the maximum biosorption capacities obtained were 2.22 and 7.14 mg/g for Cu(II) and Pb(II) respectively. Finally, breakthrough curves in single systems for Cu(II) and Pb(II) were reported and they were compared with breakthrough curves for binary metal solutions. The competition between ions in the column were evaluated according to some obtained parameters, as biosorption capacity, amount of metal loading on pine nuts shell surface, total biosorption yield, breakthrough and exhausted times etc. [ABSTRACT FROM AUTHOR]

In the present work, biosorption of copper(II) in the presence of lead(II) ions by olive stone and pine bark was investigated in batch and continuous mode. Particularly, it pretends provide new information regarding binary biosorption of metals in continuous flow. The behavior of competitive Cu(II) and Pb(II) biosorption in batch was successfully described by the multicomponent Sips model, obtaining maximum capacities for Cu(II) and Pb(II) of 1.34 and 2.12 mg/g, respectively for olive stone, and 6.05 and 10.04 mg/g, respectively, for pine bark. Olive stone and pine bark removed the target metal ions in the selectivity order of Pb(II)>Cu(II). In continuous mode the biosorption capacity for Pb(II) (6.59 and 26.01 mg/g for olive stone and pine bark, respectively) were also higher than copper one (2.19 and 12.66 mg/g for olive stone and pine bark, respectively), indicating the higher affinity of lead for the two biosorbents in continuous system too. Finally, the results of this study demonstrated that pine bark could be a better biosorbent than olive stone. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 192-204, 2014 [ABSTRACT FROM AUTHOR]

Highlights: [•] This work includes a complete physic-chemical characterization of olive tree pruning. [•] It is observed that treatments affect mainly the external surface. [•] The SEM micrographs indicated changes in biomass physical structure. [•] The experiments showed that these materials could be good for heavy metals removal. [Copyright &y& Elsevier]