Removal of nickel(II) from aqueous solution by Vigna unguiculata (cowpea) pods biomass.

The potential to remove nickel(II) ions from aqueous solution using a biosorbent prepared from Vigna unguiculata pods (VUPs) was investigated in batch experiments. The batch mode experiments were conducted utilising the independent variables of pH (2 to 8), contact time (5 to 120 min), dosage concentration (0.2 to 1.