Upadhyay, Sudhir K.Devi, PriyankaKumar, VinayPathak, Himanshu K.Kumar, PrasannRajput, Vishnu D.Dwivedi, Padmanabh2025-01-282025-01-282023456535https://dl.bhu.ac.in/ir/handle/123456789/22825In this investigation, marigold flower-waste was activated with iron salts (MG-Fe), subsequently marigold plant extract (MG-Fe-Ex) for the adsorptive elimination of As3+ and As5+ from contaminated water. The governing factor such as medium pH, temperature, pollutant concentration, reaction time, adsorbent dose were considered for the study. The complete elimination of As3+/5+ was recorded with MG-Fe-Ex at pH 8.0, 90 min, 30 �C, dose 4 g/L, 20 mg/L of As3+/5+ and shaking rate 120 rpm, while under the identical experimental condition, MG-Fe exhibited 98.4% and 73.3% removal for As5+ and As3+, respectively. The MG-Fe-Ex contains iron oxides (Fe2O3 and Fe3O4) as a result of iron ions reaction with plant bioactive molecules as evident from x-ray diffraction analysis (XRD), energy dispersive x-ray spectroscopic (EDS) and Fourier transform infrared (FTIR) spectroscopic study. The adsorption data of As3+/5+ on MG-Fe and MG-Fe-Ex was best fitted by pseudo-first order kinetic and freundlich isotherm except As5+ adsorption on MG-Fe-Ex that can be described by langmuir isotherm model. The prevailing mechanism in adsorption of As3+/5+ on both adsorbent might be hydrogen bonding, electrostatic attraction and complexation. From the above, it is confirmed that MG-Fe-Ex adsorbent has high potential and can be used for the adsorptive elimination of As3+/5+ from contaminated water in sustainable and environmentally friendly way. � 2022enArsenic contaminantExtract activated biomassIsothermKineticMarigold flower wasteRemovalArticlehttps://doi.org/10.1016/j.chemosphere.2022.137551