Abstract
Removal of nickel (II) and copper (II) from aqueous solutions using NaBH4 as a reducing
agent was studied. Reduction crystallization was achieved in a batch reactor at 65oC
using seeded experiments. The effect of using different molar ratios of [Ni2+]:[BH4-]
namely; 1:1, 1:0.25 and 1:0.1 and seeding materials on the rate of reduction was also
investigated. The results obtained showed that NaBH4 is an effective reducing agent for
the removal of Ni2+ and Cu2+ from effluents. Using a molar ratio of 1:0.1 of [Ni2+]:[BH4-]
and Fe and Ni as a seeding material over 99% metal removal was achieved. Ni as a
seeding material yielded the best results as it is autocatalytic although there was no
significant difference in the rate of reduction compared to that obtained when Fe was
used as a seeding material.