Vol.:(0123456789) 1 3 https://doi.org/10.1007/s41101-021-00106-z ORIGINAL PAPER Optimization of Adsorption Parameters for Efective Removal of Hexavalent Chromium Using Simarouba glauca from Aqueous Solution Alka Banchhor 1  · Madhurima Pandey 1  · Piyush Kant Pandey 2 Received: 19 February 2021 / Revised: 24 May 2021 / Accepted: 31 May 2021 © The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. 2021 Abstract The aim of this research was to see whether a biosorbent derived from the Simarouba glauca plant can efectively remove Cr(VI). The initial concentrations, pH, biosorbent dosage, temperature, and contact time, among other things, were optimized. As a result, the biosorption capacity was obtained as 10.90 mg/g at an optimized pH of 2, a standing time of 45 min, and a temperature of 27 °C in the batch mode operations. The optimum contact time was found to decrease with an increase in temperature and biosorbent dose. The adsorption kinetics was studied with Langmuir, Freundlich, Temkin, Dubinin–Radu- shkevich, Elovich, and Jovanovic adsorption isotherm models. The Langmuir adsorption isotherm was found to ft the best with the highest R 2 (0.99) value. The adsorption efciency was studied kinetically, and the adsorption process was found to follow the pseudo-second-order reaction. Elovich kinetics model proved the chemical adsorption mechanism between the active sites and Cr(VI) ions. The adsorption mechanism was found to involve intraparticle difusion of Cr(VI) ions. The vari- ability and the endothermic nature of the reaction are shown by the positive value of ΔS˚(0.207 kJ/mol) and ΔH˚ (60.168 kJ/ mol), respectively. Also, the negative ΔG˚ values show the spontaneity of the reaction. FTIR study revealed the involvement of hydroxyl(-OH), alkane(-CH), alkyne, and carbonyl group in adsorption. The aggregate of Cr(VI) within the voids in the biosorbent was proved by SEM–EDX analysis. The biosorbent showed the regeneration efciency of 74% after fve successive adsorption–desorption cycles with 0.1 N HNO 3 . Overall, the present plant biosorbent has proved to have a high capability for removing Cr(VI) from synthetic and industrial water and can be employed at a large scale in a continuous process. Keywords Biosorption · Batch study · Cr(VI) · FTIR · SEM–EDX · Simarouba glauca Introduction Chromium is a widely used metal for numerous industrial activities. Various industrial activities like chromite ore mining and its processing, chrome plating, manufacture of dyes, pigments, chromium compounds, leather tanning, wood preserving, production of catalysts, surface treatments, and refractories use the chromium-containing compounds. The waste generated during these manufacturing processes is causing many cases of hexavalent chromium pollution. Cr(VI) is highly toxic and carcinogenic even in low concen- tration, and due to their mobility in natural water ecosys- tems, they are prioritized as major inorganic contaminants of the environment. According to the Environmental Protec- tion Agency (EPA), the highest permissible concentration of total chromium discharge into potable drinking water is 0.05 mg/L inland, and in the surface water, it is 0.1 mg/L [1]. The Cr(VI) concentration mainly depends upon the pres- ence of the industries in the surroundings. For instance, in Ranipet, Tamil Nadu, many wells were contaminated due to the industries located in the close vicinity. Cr(VI) concentra- tion in the wells varied from 2.1 to 214 mg/L [2, 3]. These concentrations were far more than the prescribed limits. B. Shankar (2009) reported that out of thirty groundwater * Madhurima Pandey pandeymadhurima01@gmail.com Alka Banchhor alka.banchhor@bitdurg.ac.in Piyush Kant Pandey drpiyush_pandey@yahoo.com 1 Department of Applied Chemistry, Bhilai Institute of Technology, Durg, Chhattisgarh, India 491001 2 LCIT Group of Institutions, Near High Court, Raipur Road, Bilaspur, Chhattisgarh, India 495001 / Published online: 21 July 2021 Water Conservation Science and Engineering (2021) 6:127–144