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An important challenge today is to efficiently monitor the presence of polar pharmaceuticals and drugs in surface and drinking waters to ensure its safeness. Most studies rely on grab sampling techniques, which enable the determination of contaminants at a given point and given time. In this study, we propose the use of ceramic passive samplers (CPSs) to increase the representativeness and efficiency of organic contaminant monitoring in waters. Firstly, we have assayed the stability of 32 pharmaceuticals and drugs and found that five of those compounds were unstable. Moreover, we evaluated the retention capabilities of three sorbents (Sepra ZT, Sepra SBD-L, and PoraPak Rxn RP) in solid-phase extraction (SPE) mode and found no differences in terms of recoveries for all three sorbents. We then calibrated CPSs using the three sorbents for the 27 stable compounds over 13 days, with a suitable uptake for 22 compounds with sampling rates between 0.4 and 17.6 mL/day, which indicates high uptake efficiency. CPSs with the Sepra ZT sorbent were deployed in river water (n = 5) and drinking water (n = 5) for 13 days. Some of the studied compounds occurred with a time-weighted concentration, for instance, of 43 ng/L for caffeine, 223 ng/L for tramadol or 175 ng/L for cotinine in river water.

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., Peer Reviewed, Postprint (author's final draft)

The presence of sewage-borne Organic Micro-Pollutants (OMP) in Wastewater Treatment Plants (WWTP) effluents represents an increasing concern when water is reclaimed for irrigation or even indirect potable reuse. During eighteen months, an innovative hybrid water reclamation scheme based on a Membrane Biological Reactor (MBR) enhanced with Powder Activated Carbon (PAC) was operated at pilot-scale (70 m3/d) in order to compare it with state-of-the art Wastewater Reclamation System (WWRS) also revamped with a final step of ozonation-UV. Removal of persistent OMP, water quality and treatment costs were evaluated and compared for the different treatment schemes. OMP removal efficiency results for the different schemes concluded that established technologies, such as physico-chemical and filtration systems as well as MBR, do not remove significantly (>15%) the most recalcitrant compounds. The upgrading of these two systems through the addition of ozonation-UV step and PAC dosing allowed improving average recalcitrant OMP removal to 85±2 and 75±5 %, respectively. In term of costs, PAC-MBR represents an increase of 37 % of costs regarding conventional systems but presents improvements of 50 % reduction in space and water quality. On the other hand, ozonation requires up to a 15% increase of foot-print; nevertheless, represents lower costs and lower carbon footprint. Ozonation-UV seems to be the best option for upgrading existing facilities, while PAC- MBR should be considered when space represents a critical limitation and produced water is reused for high water quality purposes., Postprint (author's final draft)

Understanding organic fouling on ultrafiltration (UF) membranes during water filtration and cleaning episodes has become one of the major factors driving UF technology forward. The aim of this study was to quantify and characterise the organic foulants on an UF membrane at a full-scale drinking water treatment plant when it is fed with surface water and groundwater with different dissolved organic carbon (DOC) contents. DOC characterisation was performed by high-performance size-exclusion chromatography and fluorescence excitation–emission matrix (FEEM). The masses of DOC (and its fractions) retained by the membrane over a whole filtration period (and detached during cleaning episodes) were calculated through mass balances. Under river water feeding conditions, DOC was retained by 22%, being biopolymers the most retained DOC fraction (59%), followed by humic substances (17%) and other minor organic fractions. Routine backwashing resulted in the detachment of only 8% of the total mass of DOC retained, with biopolymers as the most detached fraction (27%). Within biopolymers, proteins appeared to contribute more to hydraulically irreversible fouling than polysaccharides. Under groundwater feeding conditions, no apparent retention of DOC was observed. FEEM analyses showed neither significant removal of fluorescent components during filtration nor detachment from the UF membrane during routine backwashing., Preprint