Removal of Pesticides from Water using Magnetite-Activated Charcoal

To remove three of the most commonly used pesticides including azoxystrobin (AZX), nitenpyram (NIT) and thiamethoxam (TMX) from water, a magnetite-activated charcoal composite was synthesized, characterized using FT-IR, SEM and TEM and evaluated. The prepared composite was compared for its sorption ability with activated charcoal. Except azoxystrobin, other two pesticides were better adsorbed on the magnetite charcoal composite. Further, fitting of data to isotherm models showed that Freundlich model best described the adsorption showing a heterogeneous multilayer adsorption phenomenon with maximum sorption capacity of 3706.8 μg g⁻¹ for nitenpyram, 3288.51 μg g⁻¹ for azoxystrobin and 3250.87 μg g⁻¹ for thiamethoxam. The standardized regeneration protocol showed great efficiency as after three reusability cycles only 8–9% decline in sorption was observed. Therefore, such magnetite-activated charcoal composites are highly cost-effective, eco-friendly alternatives for removal of pesticides from wastewater.