Adsorption of metribuzin from aqueous solution using magnetic and nonmagnetic sustainable low-cost biochar adsorbents

Abstract

Switchgrass biochar (SGB) was made by fast pyrolysis in an auger-fed reactor at 425 °C with a solid residence time of 60 s in the pyrolysis zone during bio-oil production. Magnetic switchgrass biochar (MSGB) was prepared by iron oxide precipitation onto the biochar surface using an aqueous Fe/Fe solution followed by NaOH treatment. Both the SGB and the MSGB were characterized by FTIR, SEM, SEM-EDX, TGA, pH, elemental analysis, and surface area measurements. Batch sorption studies of metribuzin from aqueous solutions were carried out at different pH values, adsorbate concentrations, and temperatures. The adsorption of metribuzin onto both biochars was highest at a pH of 2. Adsorption isotherms were evaluated from 25 to 45 °C using the Freundlich, Langmuir, Redlich-Peterson, Toth, Sips, Koble-Corrigan, and Radke-Prausnitz adsorption models. Langmuir adsorption capacities at pH 2 were Q ~ 151, 223, and 205 mg/g and Q ~ 155, 205, and 155 mg/g at 25, 35, and 45 °C, respectively. Low-cost magnetization of the biochar occurred without significant loss of absorption capacity, enabling facile separation of slurried biochar from liquids following contaminate absorption. Graphical abstract ᅟ.

Use of the Solid By-Product of Anaerobic Digestion of Biomass to Remove Anthropogenic Organic Pollutants with Endocrine Disruptive Activity

“…The two less water-soluble BOS and OP showed the great the DIG sample, their concentration on the material being about 6 and 7 respectively, than that of MET. The lower adsorption of MET on organic su pared to other pesticides and ECDs, is generally responsible for the high mo in soil and sediments and the consequent dangerous release into natural wa Although, as expected, the extent of DIG sorption in this study was somehow lower than that of biochar for MET [26,27,36], BOS [8], BPA [37] and OP [24], it can be considered remarkable and suggests a valuable use of this material as biosorbent. To the best of our knowledge, the literature does not report information on the removal of the four molecules studied by the DIG alone.…”

Application of Modified Spent Mushroom Compost Biochar (SMCB/Fe) for Nitrate Removal from Aqueous Solution

“…Biochar has attracted much attention due to its excellent adsorption capacity for pollutants in aqueous solution. However, the need for centrifugation and filtration steps may limit the large-scale application of biochar in wastewater [21][22][23]. Biochar surfaces are normally negatively charged and may facilitate positive-charged adsorption, but may be inefficient in adsorption for anions such as nitrate, which are abundant in farm wastewater and priority pollutants for water quality control.…”

Soil Amendment with Biochar, Hydrochar and Compost Mitigates the Accumulation of Emerging Pollutants in Rocket Salad Plants

“…These amendments' behavior is essentially due to the numerous sorption sites present on the organic components where pollutants can be linked with bonds of different types and strengths. For instance, MET sorption onto BC occurs mainly through H bonds and Coulombic forces and, to a lesser extent, through van der Waals, dipole-dipole, and π-π interactions (Essandoh et al 2017). The carbonized phase of BC can adsorb OP through chemical interactions involving covalent and H bonds (Loffredo and Taskin 2017).…”