Abstract

Given the widespread distribution of pesticides in our environment, it is crucial to identify low-cost interventions to mitigate their occurrence and detrimental health effects. This study aimed to evaluate the potential use of agro-industrial by-products with little value (peels from cassava roots, crambe meal, and pinus barks) as biosorbents to be used un-modified or modified through adding different reagents such as H2O2, H2SO4, or NaOH. Firstly, the biosorbents were characterized by their pH of the point of zero charge (pHPZC), their surface functional groups (FT-IR), morphological (scanning electron microscopy mi-crographs), and textural characteristics (specific surface area, pore-volume, and pore size). Adsorption studies were also conducted to evaluate the influence of the pH, adsorbent dose, contact time between adsorbent-chlorpyrifos, and isotherm studies. The pHPZC of the six-teen materials varied from 2.05 to 8.03; the surfaces were heterogeneous with functional groups such as C]C, C-O, N-H, COO-, N-O, C-N, C-H, and O-H. In addition, the adsorbents presented a low specific surface area and pore volume. Moreover, CPF adsorption is not dependent on the pH in the evaluated range (3.0-7.0). The optimal results were found using doses higher than 16 g L-1, with the physicochemical equilibrium set within 10-20 min. Finally, the best fit was obtained for pseudo-first order, pseudo-second order, and Freundlich, thus, suggesting multilayer CPF adsorption. Therefore, we propose using agro-industrial by-products as biosorbents as a low-cost strategy to attenuate the impact of CPF and potentially other organophosphates on water pollution.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.