Adsorption of copper(II) and lead(II) from seawater using hydrothermal biochar derived from Enteromorpha

The objective of this research was to evaluate the capacity of Enteromorpha derived biochar to adsorb heavy metals from seawater. The biochar characteristics were determined, and isothermal and kinetic data were obtained using batch experiments. Copper [Cu(II)] and lead [Pb(II)] adsorption by the biochar was favored by high pH conditions, while elevated salinity had a relatively weak negative effect on adsorption. The Langmuir isotherm and adsorption kinetics pattern enabled interpretation of the equilibrium and kinetics of Cu(II) and Pb(II) removal by the biochar. The maximum removal rates of Cu(II) and Pb(II) by the biochar in 60 min were estimated to be 91% and 54%, respectively. A model describing the adsorption processes was developed to predict the efficiency of heavy metal removal by the biochar. The outcomes of the present study indicate that Enteromorpha derived biochar could be an effective and environmentally friendly adsorbent for removing heavy metals from marine environments.