Abstract:
BACKGROUND: Certain crop-based waste materials
have been recognized as cost-effective and highly efficient
adsorbents for removal and recovery of different kind of
heavy metals from aqueous solutions. The ability is
strongly attributed to the carboxyl functional group of some
pectin substances such as galacturonic acid often found in
fruit peels. The present manuscript was aimed at assessing
the potential applicability of banana peel for metal removal
from contaminated waters.
METHODS AND RESULTS: As revealed by laboratory
investigations, banana peel contains pectin (10-21%),
lignin (6-12%), cellulose (7.6-9.6%), and hemicelluloses
(6.4-9.4%). The pectin extraction is reported to have
glucose, galactose, arabinose, rhamnose, xylose, and
galactouroninc acid. Several studies conducted under
different conditions proved that banana peel is capable of
adsorbing 5.71, 2.55, 28.00, 6.88, 7.97, and 5.80 mg/g of
Cd2+, Co2+, Cu2+, Ni2+, Pb2+, and Zn2+, respectively, from
aqueous solutions. Adsorption capacity is, however,
dependent upon several factors including solution pH, dose
of adsorbent and metal concentration, contact time and shaking speed.
CONCLUSION(S): Since the annual world production of
banana exceeds 100 million tons, about 40 million tons of
banana peel (40% of total weight of the fresh fruit) remains
vastly unused. Exploring a sound technology with banana
peel would therefore, not only address the much needed
sustainable tool for cleaning contaminated waters, but of
course bring an additional value to the banana industry
worldwide.
