Marula seed husk (Sclerocarya birrea) biomass as a low cost biosorbent for removal of Pb(II) and Cu(II) from aqueous solution

•A low cost biosorbent was prepared from marula seed husk (Sclerocarya birrea) biomass.•Biosorption follows Langmuir isotherm.•pH, biosorbent dosage, contact time, temperature, and metal concentration investigated in batch mode.•The marula seed husk biosorbent showed better performance for Pb(II) than Cu(II) removal.

A biosorbent prepared from marula seed husk (Sclerocarya birrea) was used to study the sorption of Pb(II) and Cu(II) from industrial wastewater under batch conditions. The equilibrium sorption capacities of the seed husk were 20 mg g−1 for Pb(II) and 10.20 mg g−1 for Cu(II). The biosorption data conforms best with Langmuir model for both Pb(II) and Cu(II) with correlation factors of 0.999 and 0.998, respectively. Kinetic data were properly fitted with the pseudo-second order kinetic model. The thermodynamic parameters (ΔG0, ΔS0 and ΔH0) showed that the biosorption was feasible, spontaneous and endothermic.