A facile approach for surface alteration of Pseudomonas putida I3 by supplying K2SO4 into growth medium: Enhanced removal of Pb(II) from aqueous solution

•A facile approach for altering bacteria surface by nutrient agent was developed.•P. putida I3 surface was effectively altered by adding K2SO4 into growth medium.•Alteration of bacterial surface by K2SO4 was dependent on bacterial metabolism.•KSI3-30 showed a good biosorption performance and recyclability for Pb(II).•Ion-exchange and chemical complexation were significant in Pb(II) removal.

A new sight of obtaining a high efficient biosorbent by supplying specific salts into bacterial growth medium was investigated in this study for Pb(II). Among a series of salts including Na2SO4, Na2S2O3, KCl, and K2SO4, the highest Pb(II) removal efficiency was observed by psychrotrophilic Pseudomonas putida I3 grown in the presence of 30 g/L K2SO4 (KSI3-30) with biosorption capacity of 62.89 mg/g under cold condition (15 °C), which was increased by 42.35% as compared to control (without any additive, RI3). This stimulation effect was ascribed to the increase of potassium and sulfur containing groups on KSI3-30 surface via metabolic dependent ways. The probable mechanism for Pb(II) adsorption was ion-exchange and chemical complexation. The thermal and kinetic data well fitted to Langmuir adsorption model and pseudo-second order and intraparticle diffusion kinetic model. Good recyclability and effectively dealing with real wastewater suggested KSI3-30 was a promising biosorbent for Pb-contaminated wastewater treatment.