Hybrid sorption and pressure-driven membrane technologies for organic micropollutants removal in advanced water reclamation: A techno-economic assessment

Abstract

The persistence of certain organic-micropollutants (OMP) in conventional wastewater and reclamation treatments represents a growing concern due to its associated uncertain effects on human health and the environment. This issue highlights the need to resort to advanced treatment technologies to ensure the maximum removal of these compounds. A prototype (1.5–2 m3/h) based on the combination of powdered activated carbon (PAC) with tight ultrafiltration (UF) membranes was operated in El Baix Llobregat Water Reclamation Plant (WRP) for 18 months. Its performance was compared from a technical and economic point of view with the current full-scale ultrafiltration and reverse osmosis system (UF-RO with 50% blend). The application of a PAC concentration of 20 mg/L and its separation with UF membrane resulted in an average removal up to 81 ± 13% of the most recalcitrant OMP detected (Carbamazepine (CBZ), Diuron (DIU), Diclofenac (DCF), Erythromycin (ERY) and Sulphametoxazole (SMX)), while in UF-RO (50% blend), the average removal was 55 ± 11%. PAC-tight UF presented promising advantages for when these post-treatments need to be implemented in inland WRP and where brine management can represent a drawback. Moreover, PAC-tight UF presents 22% higher Operational Expenditures (OPEX) than UF-RO (50% blend), although in terms of Capital Expenditure (CAPEX), it appears as the less expensive option.