Reusable nanocomposite-filters for arsenite and arsenate dual real effluents remediation in an up-scaled membrane reactor

Abstract

A membrane reactor (MR), combining adsorption and membrane separation processes, represents a new hybrid and promising technology for arsenic-contaminated water treatment. This work reports on nanocomposite filters (NCFs) based on poly (vinylidene fluoride-hexafluoropropylene), PVDF-HFP, containing yttrium carbonate (Y2(CO3)3) and magnetite (Fe3O4) to adsorb neutral and anionic species of As(III) and As(V), in an up-scaled membrane reactor. The nano-sorbents and the NCFs were thoroughly characterised concerning morphological and physical-chemical properties. Incorporating the nano-sorbents does not affect the main characteristics of the NCF. Flow rate and pH of the media are the main parameters affecting the adsorption efficiency: lower flow rates and acidic pH are the most favorable conditions for dual As(III) and As(V) adsorption. Y@Fe3O4/PVDF-HFP adsorption follows pseudo-second-order kinetics described by Langmuir isotherm model, reaching maximum absorption capacities of 101.9 and 212.8 mg/g for As(III) and As(V), respectively. In addition, the NCFs proved to be effective for the removal of As(III) and As(V) in treated effluents and easily reactivated and reused without significant efficiency losses. Thus, Y@Fe3O4/PVDF-HFP nanocomposite filters and the designed up-scaled membrane reactor represent a straightforward, efficient, reusable, and low-cost alternative for a continuous treatment process for As(III) and As(V) remediation in real condition effluents sources.