Abstract:
Natural and anthropogenic activities generally result to large production of heavy metals. These heavy
metals produced are indiscriminately discharged into rivers and other water bodies. Wastewater
treatment of industrial effluents become very necessary due to toxic effect of heavy metal pollutants and
its indirect effect pose to human health. Banana peel, an agricultural waste biomass can be used to
produce bio-sorbent for adsorption of heavy metals from industrial wastewater. This study focused on
the production of chemically modified activated carbon using various concentrations of phosphoric acid
for removal of lead and zinc metals from aqueous solution. Activated carbon was produced from waste
banana peel through thermal pretreatment at temperature of 450℃ preceding chemical modification
with different concentrations of phosphoric acid of 0.5 M, 1.0 M and 1.5 M. The three different
concentrations of the phosphoric acids represent sample X, Y and Z respectively. To study the
adsorption efficiency of chemically modified activated carbon using different concentrations of
phosphoric acid, batch experiments were conducted on chemically modified samples to assess the
adsorption of lead (II) and zinc metals from aqueous solution. The three adsorbents were interacted with
varying parameters such as effect of initial concentration of lead and zinc metal of concentration of 10
mg/L and 2 mg/L respectively. Based on batch experiments conducted, results indicated that adsorbent
dose, pH, initial concentration as well as contact time are important factors influencing lead (II) and Zinc metals adsorption from aqueous solutions. Percentage adsorption of lead (II) and zinc metals was
above 80 % for all three chemically modified adsorbents investigated. The adsorption capacities of the
adsorbents under study showed high adsorption capacity for both zinc and lead metals. This implies
that sample X, Y and Z are good adsorbents for adsorption of both zinc and lead metals in an aqueous solution.
