Combined nanofiltration and photo-Fenton treatment of water containing micropollutants

The purpose of this study was to find out whether the use of a combination of nanofiltration (NF) and solar photo-Fenton is more efficient than photo-Fenton alone as a tertiary treatment. Five different pharmaceuticals (carbamazepine, flumequine, ibuprofen, ofloxacin, and sulfamethoxazole) dissolved (100 μg L−1) in natural water were preconcentrated by NF and treated by solar photo-Fenton. Photo-Fenton was operated at pH 5 with 5 mg L−1 of Fe2+. The NF system consists of two membranes operating simultaneously with a total surface area of 5.2 m2. The photo-Fenton experiments were carried out in a 3 m2 CPC solar pilot plant with a 35 L total volume. Hydrogen peroxide consumption and the pharmaceutical removal rate were used as the key evaluation parameters. It was demonstrated that at higher initial concentrations of microcontaminants, hydrogen peroxide is used more efficiently and NF pretreatment also reduced the photo-Fenton treatment time. Combined NF and photo-Fenton treatment was therefore found to be a promising approach for wastewater containing extremely low concentrations of microcontaminants.

► Combination of nanofiltration (NF) and solar photo-Fenton is presented.
► Carbamazepine, flumequine, ibuprofen, ofloxacin, and sulfamethoxazole at 100 μg/L in natural water were tested.
► Nanofiltration/photo-Fenton is compared with photo-Fenton.
► Hydrogen peroxide consumption and treatment time need for photo-Fenton were lower when combined with nanofiltration.