Linearity and non-linearity analysis of isotherms and kinetics for ibuprofen remotion using superheated steam and acid modified biochar

Abstract

Adsorption capabilities of physically activated Cocos nucifera shell biochar (CPBC) and chemically activated Cocos nucifera shell biochar (CCBC) were explored towards Ibuprofen (IBP) removal from simulated water in the present study. Impact of adsorbent dose (0.033–10 g L−1), pH (1–7), initial ibuprofen concentration (1–50 mg L−1), agitation speed (100–200 rpm), contact time (0.5–24 h) and temperature (15–40 °C) were conferred to designate the performance estimation of CPBC and CCBC towards IBP adsorption. Surface morphology and chemistry of CPBC and CCBC were studied using scanning electron microscopy (SEM) and FT-IR spectroscopy for better evaluation of sorbents characteristics on IBP removal. Assessment of linear and non-linear methods of isotherms and kinetics models were considered for validation of sorption study. The results were exposed from isotherm and kinetic model that non-linear methods evidenced to be an expressively better substitute for fitting the experimental data with more accuracy than linear form. While Langmuir isotherm and pseudo-first order kinetic were appeared to be the best-fitted models of IBP sorption study. Sorptive uptake of IBP by CPBC and CCBC were 9.69 mg g−1 and 12.16 mg g−1 respectively. The thermodynamic study revealed the exothermic, spontaneous and feasible nature of IBP sorption process by CPBC and CCBC. Reusability of both sorbents showed its efficacy of IBP adsorption to multiple cycles. Cost analysis of CPBC and CCBC production validates cost-effectiveness of both the sorbents. Consequently, the activated form of C. nucifera (coconut shell) derived biochar presented prospective candidature as a sorbent for ibuprofen adsorption.