Removal of 2,4-D, glyphosate, trifluralin, and butachlor herbicides from water by polysulfone membranes mixed by graphene oxide/TiO2 nanocomposite: study of filtration and batch adsorption.

Abstract

Degradation or decomposition of the chemical herbicides by natural reagents after using can lead to produce various types of harmful intermediates. Ultrafiltration by the mixed matrix membranes blended with the graphene oxide/TiO2 can remove the residual herbicides from aqueous solution. Graphene oxide/TiO2x% (x = 10, 30, 50%) was prepared by solvothermal method and blended by polysulfone to prepare GO/TiO2/PSf membranes for dynamic rejection of aqueous solutions of glyphosate, 2,4-D, butachlor, and trifluralin in a dead-end flow system. The blended membranes were also applied for the adsorption of herbicides in batch experiments. Addition of GO/TiO2 nanocomposite increased water flux from 7.3 for pure membrane to 211-326kg/m2h for mixed matrix samples in order to increase of the membrane porosity and surface hydrophilicity. The herbicides rejections were found in the range of 50-70% related to GO/TiO2 content. It was found that the membrane blended with 0.5wt.% of GO/TiO2(10%) demonstrated the most efficiency. Details of dynamic filtration showed that the blended membrane acted based on the size exclusion mechanism. Adsorption experiments indicated that the strong attractions between H-bond donor sites of the herbicide and GO/TiO2 nanoparticles in membranes played a key role in the increase of adsorption of herbicides on the membrane.