Prediction of the pH effect on arsenic (V) removal by varying catalyst of magnetic xerogel monoliths based on FREN model Sasirot Khamkure, Chidentree Treesatayapun, Sofía Esperanza Garrido-Hoyos, Prócoro Gamero-Melo and Audberto Reyes-Rosas ABSTRACT Magnetic xerogels monoliths (MCs) were simultaneously prepared and formed by the cross-linking polymerization of resorcinol and formaldehyde using the alkaline catalyst and magnetite. The varying of molar ratio of resorcinol and catalyst (R/C) was studied and characterized by isoelectric point (IEP), point of zero charge (pHpzc), scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), N 2 adsorption and Fourier transform infrared spectroscopy (FTIR). The result of XRD and EDX confirmed the presence of magnetite into the gel at 1.19% with low molar ratio of magnetite and resorcinol ratio at 0.01. The surface morphology and textural properties of MCs affect directly with S BET , total pore volume and volume of mesopore increase when molar of R/C increases. The behavior of arsenic (As(V)) adsorption by using MCs, was studied in groundwater into the ranges of pH from 2.0 to 7.0. MC50 shows the maximum As(V) uptake and removal were 72 μg/g and 73.5% at pH 5, respectively, while MC100 gave the best performance within the application range of pH both of acidic and neutral region. Furthermore, the prediction technique based on an adaptive fuzzy rules emulated network was utilized for evaluation of the arsenic removal performance. Key words | adsorption, arsenic, fuzzy rules network, magnetite, prediction, xerogel HIGHLIGHTS • Synthesis and characterization of magnetic monolithic xerogels by using Fe 3 O 4 . • Effect on catalyst variation to pH solution on As(V) adsorption in groundwater. • The prediction and evaluation of As removal performance based on an adaptive fuzzy rules emulated network (FREN). • The comparison of the uptake of As(V) obtained from the adsorption experiment and estimation of FREN. Sasirot Khamkure (corresponding author) CONACYT-Instituto Mexicano de Tecnología del Agua, Jiutepec, Morelos, 62550, Mexico E-mail: bongy222@gmail.com Chidentree Treesatayapun CINVESTAV IPN-Unidad Saltillo, Ramos Arizpe, Coahuila, 25900, México Sofía Esperanza Garrido-Hoyos Instituto Mexicano de Tecnología del Agua, Jiutepec, Morelos, 62550, México Prócoro Gamero-Melo CINVESTAV IPN-Unidad Saltillo, Ramos Arizpe, Coahuila, 25900, México Audberto Reyes-Rosas Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México 2747 © IWA Publishing 2020 Water Supply | 20.7 | 2020 doi: 10.2166/ws.2020.168 Downloaded from http://iwaponline.com/ws/article-pdf/20/7/2747/788314/ws020072747.pdf by guest on 01 April 2022