Abstract Presence of heavy metals in the aquatic system is posing serious problems and chromium
has been used in many industries and the removal of chromium ions from waste waters is significant.
Biosorption is one of the economic methods that is used for the removal of heavy metals.
In the present study, the biomass generated from the dried Spirulina sp. was used for evaluating
the biosorption characteristics of chromium ions in aqueous solutions. Batch adsorption experiments
were performed on these leaves and it was found that the amount of metal ions adsorbed
increased with the increase in the initial metal ion concentration. In this study effect of agitation
time, initial metal ion concentration, temperature, pH, and biomass dosage were studied. Maximum
metal uptake was observed at pH = 5. Maximum metal uptake (qmax) was 90.91 mg/g .The biosorption
followed both Langmuir and Freundlich isotherm models but the Freundlich isotherm
model was better than the Langmuir with R2 = 0.997. The adsorption equilibrium was reached
in about 1 h. The kinetics of biosorption followed the second-order rate. The biomass could be
regenerated using 0.1 M HNO3. FTIR Spectrums of biomasses revealed the presence of hydroxyl,
amino, carboxylic and carbonyl groups. The scanning electron micrograph clearly revealed the surface
texture and morphology of the biosorbent.
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