Adsorption of atrazine from aqueous solution using unmodified and modified bentonite clays

Abstract

Properties of raw bentonite clay of Afuze in Edo state which are abundant and cheap bentonite mineral in Nigeria as adsorbents for the removal of atrazine in aqueous solution were investigated. The bentonite clay-types were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectrophotometry and X-ray diffraction (XRD). Batch adsorption experiments were carried out to determine the equilibrium characteristics, thermodynamics and kinetics of the sorption processes. The data obtained were subjected to Langmuir, Freundlich and Temkin isotherm equations, while pseudo-first-order, pseudo-second-order rate equations, intra-particle diffusion and Elovich models were considered for kinetics and mechanism. The results showed that the adsorption processes were described by different isotherm models; they were all spontaneous (∆G ranges from − 938.34 to − 6263.58 kJ/mol) and exothermic (range of ∆H is − 252.73 to − 1057.08 kJ/mol), and with decreased randomness, ∆S (− 3.110 to − 0.581 J.mol/K). Pseudo-second-order kinetics model gave the better fit for all the sorption processes which implies physisorption process as the rate limiting step. Thus, bentonite clay-types can be used to adsorb atrazine.

Biochar Derived from Pineapple Leaf Non-Fibrous Materials and Its Adsorption Capability for Pesticides

“…Moreover, results of kinetic studies also suggest that adsorption kinetics were best described by the PSO kinetic model, with a high correlation coefficient ( R 2 > 0.99) and the lowest χ 2 , for single adsorption of pesticides on the NFMBC via prevalent chemisorption processes for all pesticides studied . These results are consistent with previous studies on adsorption of pesticides by biochar sorbents, in which the pseudo-second-order model has a better fit to the experimental data than others. ,, Additionally, the higher values of α relative to β in the adsorption process from the Elovich model indicate that the initial rate of adsorption is higher than the desorption rate, implying that NFMBC is an effective sorbent for aqueous pesticide removal.…”

“…61 These results are consistent with previous studies on adsorption of pesticides by biochar sorbents, in which the pseudo-second-order model has a better fit to the experimental data than others. 52,57,62 Additionally, the higher values of α relative to β in the adsorption process from the Elovich model indicate that the initial rate of adsorption is higher than the desorption rate, 63 implying that NFMBC is an effective sorbent for aqueous pesticide removal. Next, intra-particle diffusion and liquid-film diffusion models were applied to study the rate-controlling mechanism for adsorption of pesticides on NFMBC.…”

Magnetic sugarcane bagasse composite for atrazine and fluoride removal

“…They studied the process at three different temperatures with a maximum adsorption capacity of 47.2 mg g –1 at 35 °C. Atrazine removal by natural and H 2 SO 4 ‐ and NaOH‐modified bentonite was reported by Ajala et al ,. giving removal capacities of 76.92, 125.0 and 111.1 mg g −1 , respectively.…”

A review of Pharmaceuticals removal from water resources using magnetic iron-based nanomaterials

“…Due to the regular occurrence of pharmaceuticals in global water resources, its risks, such as the development of antibiotic resistance and toxicity to aquatic life, it is imperative to develop appropriate technologies that can specifically removal pharmaceuticals from water (Shehu et al, 2022;. The conventional water and wastewater treatment methods are advanced oxidation, reverse osmosis, ultrafiltration, electrochemical methods, coagulation-flocculation, precipitation, ion exchange, and adsorption (Ajala et al 2018). However, these technologies are not effective in the removal of pharmaceuticals from water and wastewater, and a number of these compounds are frequently detected in water bodies despite the presence of water treatment facilities Wang & Chu, 2016;Wang & Zhuan, 2020).…”