Abstract

Hassan Rezaei^*, Satish D. Kulkarni and Praveen G. Saptarshi

In the present study, the biomass generated from the dried Chlorella pyrenoidosa was used for evaluating the biosorption characteristics of Ni 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 & biomass dosage were studied. Maximum metal uptake was observed at pH= 5. Maximum metal uptake (q_max) was 142.86 mg/g .The biosorption followed both Langmuir and Freundlich isotherm model .The adsorption equilibrium was reached in about 1 h. The kinetic of biosorption followed the second - order rate. The biomass could be regenerated using 0.1 M HNO₃. A positive value of H° indicated the endothermic nature of the process. A negative value of the free energy (G°) indicated the spontaneous nature of the adsorption process. A positive value of S° showed increased randomness at solid-liquid interface during the adsorption of heavy metals, it also suggests some structural changes in the adsorbate and the adsorbent. FTIR Spectrums of Chlorella pyrenoidosa revealed the presence of hydroxyl, amino, carboxylic and carbonyl groups. The scanning electron micrograph (SEM) clearly revealed the surface texture and morphology of the biosorbent.

Biosorption; Chlorella pyrenoidosa; Ni; Isotherm models; Kinetic

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