Reusable graphene oxide-based composite membranes for highly efficient and fast removal of pesticides from real water matrixes

Water contamination caused by the excessive use pesticides is a growing concern, as these chemicals threaten both human health and ecosystems biodiversity. Current remediation methods are often ineffective in addressing these contaminants, highlighting the need for new solutions. This work reports on graphene oxide (GO)-based composite membranes developed through different strategies for the adsorption of thiacloprid (THI) from wastewater. GO shows adsorption capacity of 35.7 mg/g after only 3 min, and composite membranes incorporating GO into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were prepared by the thermally induced phase separation (TIPS) and salt leaching (SL) methods. The SL-prepared membranes exhibited superior porosity, hydrophilicity, and active site availability, achieving the highest THI adsorption capacity of 84.6 mg/g for the 40 % GO@PVDF-HFP sample, after 45 min. Adsorption kinetics and isotherms followed a pseudo-second order and Langmuir models, respectively, indicating a chemisorption process. These membranes demonstrated effective THI removal from both surface and groundwater effluents and a consistent performance over multiple cycles. The adsorption mechanism was also unveiled by confirming hydrogen bonding as the main contribution to the adsorption process.

These findings underscore the suitability of GO-based membranes for water remediation, offering robust performance under environmentally relevant scenarios, making them suitable for advanced water treatment technologies.