Exploring the adsorption and desorption characteristics of lead(II) ions from synthetically contaminated wastewater by anionic surfactant modified neutral alumina

Civil Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur-721 302, West Bengal, India E-mail: anjalipal@civil.iitkgp.ac.in Manuscript received online 08 December 2020, accepted 27 December 2020 In our previous studies, it has been shown that anionic surfactant (AS) can be removed from water media by neutral alumina through adsorption and subsequent bilayer formation. In this study, it has been shown that after the AS adsorption, the spent sludge can be used for Pb(II) removal from water. The modified alumina upon surfactant loading (which can be regarded as a waste material) is utilized to remove another waste. The effects of several parameters important for the operation, like dose of adsorbent, initial level of concentration of Pb(II), shaking speed, temperature, and also pH are studied. The maximal adsorption capacity has been reported to be 30.3 mg/g under optimized condition. The experimental data follows the reaction kinetics of pseudo-second order model. The investigation to establish isotherm shows a better correlation with Freundlich isotherm model in contrast to Langmuir model. The process can be inferred as favorable, spontaneous, and exothermic by the obtained values of thermodynamic parameters