Abstract:
Adsorption of reactive red dye from aqueous solution onto banana (Musa sapientum) peel and
avocado (Persea Americana) seed in a batch process was investigated. Adsorption was studied
as a function of solution pH, adsorbent dosage, contact time and initial dye concentration. The
effective solution pH, adsorbent dosage and equilibrium contact time for the avocado seed was
found to be 2.0, 0.8g/100ml and 120 min, respectively, and for banana peel 2.0, 0.4g/100ml
and 90 min respectively. At these experimental situations, the dye removal efficiency and the
maximum adsorption capacity of avocado seed was reached 96.28% and 1.60 mg/g
respectively, and for banana peel, it was found to be 79.73% and 2.99 mg/g respectively. The
dye adsorption processes of avocado seed and banana peel were tested with Langmuir and
Freundlich adsorption isotherm models. Avocado seed was fit well by the Langmuir isotherm
model with higher correlation coefficients value of 0.9904. However, Freundlich adsorption
isotherm showed a good fit to the banana peel adsorption process with correlation coefficients
value of 0.9728. In addition, adsorption kinetics rate were determined using pseudo first order
and pseudo second order models, and it was found that the pseudo-second-order kinetic model
better represented the adsorption kinetics of reactive red dyes on to avocado seed and banana
peel adsorbents
