Designer composite of montmorillonite-reduced graphene oxide-PEG polymer for water treatment: Enrofloxacin sequestration and cost analysis

•Three materials were synergistically combined to enhance adsorption performance.•Montmorillonite was coupled to reduce graphene oxide and polyethylene glycol methyl ether.•The composite was employed for adsorption of emerging contaminant (enrofloxacin)•Adsorption was high (310.6 mg/g), equilibrium fast (≤30 min) and optimal at pH 6.•Effective reuse (≥72 %) in real/simulated water samples after 4 cycles.