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

•Metals adsorption by a biosorbent made up non-viable P. putida trapped in agar beads.•OH, CH2, CO, COC and COP groups are involved in metal binding of biosorbent.•Cu2+ was more efficiently adsorbed than Zn2+ in both batch and column assays.•Fixed-bed column was stable up to 10 successive adsorption/desorption cycles.•Biosorbent as alternative potential for Cu2+ and Zn2+ removal from aqueous solutions.