Background: Effective treatment of wastewaters for potentially toxic metals
especially at affordable cost is critical to the well-being of man and the environment.
Objective: This study optimized the conditions for the application of Calophyllum inophyllum
seed husk as biosorbent for simultaneous removal of heavy metals from aqueous
solutions and investigated the removal efficiencies of the biosorbent for Pb2+ and
Cd2+ in wastewater samples.
Methods: The dependence of the adsorption process on pH, adsorbent dosage, temperature,
initial metal ions concentration, and contact time was evaluated in a batch system by
determining the degree of adsorption of Pb2+ and Cd2+ in simulated industrial wastewater
before application of the biosorbent for metals cleanup in industrial and domestic
Results: The results showed that charring and microwave irradiation of the biosorbent
produced the best performance. The pH of the aqueous solution played a crucial role in
the performance of the biosorbent. Optimum adsorption for both metals occurred within
the first 60 minutes of the process at pH value around 9. Kinetic studies of the process
gave good correlation coefficients for a pseudo-second order kinetic model with adsorption
data that fitted well into the Freundlich and Langmuir models but with Freundlich
isotherm displaying better fitness. The adsorption capacities of the biosorbent were 42.19
and 22.47 mg/g for Pb2+ and Cd2+, respectively.
Conclusion: The study concluded that the good adsorption capacities of Calophyllum
inophyllum seed husk for the metals is an indications of its considerable potential as a
low-cost biosorbent for simultaneous removal of potentially toxic metals from