Process Design of Groundnut Husk Waste for Pb²⁺ and Cd²⁺ Ions Mitigation in Drinking Water Purification

This present work has explored a novel application of modified Arachis hypogaea (groundnut) husk on mitigation of toxic Pb²⁺ and Cd²⁺ ions in aqueous phase. Ecotoxicological assessment of exhausted adsorbent was investigated as per standard OECD guidelines. Standard deviation, correlation coefficient, and the reduced chi square test were evaluated and compared statistically on experimental data. The results showed good sorption capacities-31.62 and 29.78 mg g^-l for Pb²⁺ and Cd²⁺ ions, respectively. Pseudo first-order rate kinetics was well correlated for Pb²⁺ and Cd²⁺ ions sorption over all kinetic models. The sorption data was in good agreement with the Freundlich isotherm for Pb²⁺ and the Sips model for Cd²⁺ ions sorption. The sorption capacity was endothermic in nature. Pb²⁺ ions desorption was three times faster than Cd²⁺ ions. The sorption mechanism was plausibly explained by spectroscopic techniques. Herein, the tailored abundant agro-waste material is a competitive sorbent and may be exploited in decontamination of metal ions in a wide range of concentrations. Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science and Technology to view the free supplemental file.