Isothermal study of Congo Red dye biosorptive removal from water by Solanum tuberosum and Pisum sativum peels in economical way

Abstract

Solanum tuberosum (STP) and Pisum sativum peels (PSP) were used for removal of toxic Congo Red dye using indigenous sources. Potato (Solanum tuberosum) and pea (Pisum sativum) are commonly and abundantly cultivated plants in Asian countries and their peels are easily available. The optimized conditions for Solanum tuberosum peels (STP) and Pisum sativum peels (PSP) were: adsorbent dose; 0.8 and 0.6 g, contact time; 50 and 35 min, pH; 3 and 2, agitation speed; 200 and 125 rpm and temperature; 30 ^oC for both STP and PSP respectively. Isothermal studies indicated that Langmuir model followed by equilibrium data more than Freundlich model. Negative value of thermodynamic parameter ∆G^o shown that Cong Red removal by both adsorbents was spontaneous and exothermic in nature. The adsorption capacity (q_max) for Solanum tuberosum and Pisum sativum peels were found to be 6.9 and 16.4 mg.g^-1, respectively. Higher value of q_max for pea peels shown that it is more suitable adsorbent for removal of Congo Red dye than potato peels.

KEY WORDS: Congo red, Solanum tuberosum, Pisum sativum, Biosorption

Bull. Chem. Soc. Ethiop. 2018, 32(2), 213-223.

DOI: https://dx.doi.org/10.4314/bcse.v32i2.3