Lemon Juice and Microwave Assisted Modification of Potato Peel Husk for Lead Biosorption: Batch and Column Studies

Abstract

The removal of heavy metals from water is very difficult. For this reason different methods have been employed so far among which biosorption is the cheapest and ecofriendly way to treat and remove heavy metals from aqueous media. Present study, investigated the ability of potato peel
husk (PPH), potato peel husk modified with lemon juice (LMPPH) and potato peel husk modified with lemon juice & microwave (MLMPPH) for the removal of Pb (II) from water. Organic adsorbent was activated by lemon juice & microwave and was characterized by SEM, EDX and FTIR. Adsorption mechanism (batch parameters) and isothermal studies (Langmuir, Freundlich, Temkin isotherms) revealed the best fitness of Freundlich isotherm from the R² values indicating physisorption. Results of kinetic studies (pseudo first and second order and intraparticle diffusion)
showed that reaction followed pseudo second order kinetics. In thermodynamic study reaction was exothermic (ΔH was negative). The ability of PPH, LMPPH and MLMPPH for removal of lead was also investigated in column studies (bed height, flow rate, influent concentration).Thomas Morrison adsorption model described breakthrough data. Recent study proved that activation of potato peel husk with lemon juice and microwave (MLMPPH) not only increased the sorption
capacity of sorbent much more as compared to PPH and LMPPH due to the introduction of excess COOH groups with lemon juice but also their activation as COO- with microwave exposure.