Removal of copper and/or zinc ions from synthetic solutions by immobilized, non-viable bacterial biomass: batch and fixed-bed column lab-scale study

MERINGER, AGUSTINA; LIFFOURRENA, ANDRÉS S.; HEREDIA, ROMINA M.; LUCCHESI, GLORIA I.; BOERIS, PAOLA S.

JOURNAL OF BIOTECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2021

0168-1656

A biosorbent composed of non-viable Pseudomonas putida trapped in agar beads was able to remove Cu2+ and Zn2+ from solutions containing one or both metals. The process in batch followed pseudo second-order kinetics, with adsorption capacities of 0.255 mg Cu2+/g and 0.170 mg Zn2+/g according to the Langmuir isotherm. These values were up to ten times lower for beads without biomass. The metals became bound to OH, CH2, C = O, C-O-C and C-O-P groups, with the last three being provided by the biomass, which highlights its importance. Adsorption values for single-metal solutions filtered in a fixed-bed column were 0.152 mg Cu2+/g and 0.117 mg Zn2+/g, but decreased to 0.075 and 0.058, respectively, with mixed-metal solutions (1:1 ratio). In 10:1-ratio solutions, the metal in greater proportion was better adsorbed. Under all conditions, removal percentage was ∼60%. The column could be reused throughout ten absorption/desorption cycles without significant alterations in adsorption capacity.