Photocatalytic Treatment of Pharmaceuticals in Real Hospital Wastewaters for Effluent Quality Amelioration

Abstract

The presence of pharmaceutically active compounds (PhACs) in the wastewater effluents has confirmed that conventional wastewater treatment technologies are not sufficiently effective in the pharmaceuticals' removal. The objective of the present study was to evaluate and compare the photocatalytic degradation of PhACs using TiO 2 -P25, graphitic carbon nitride (g-C 3 N 4 , CN) and a heterojunction of perovskite strodium titanate and graphitic carbon nitride SrTiO 3 /g-C 3 N 4 (20% g-C 3 N 4 , 20CNSTO) photocatalytic materials, in hospital wastewater effluents, by simulated solar irradiation. The experiments were performed by using real wastewater samples collected from the university hospital wastewater treatment plant (WWTP) effluent of Ioannina city (Northwestern Greece) and inherent pharmaceutical concentration levels. The analysis of the samples was accomplished by solid phase extraction followed by liquid chromatography-Orbitrap high-resolution mass spectrometry. In the cases of TiO 2 and CN, more than 70% of the initial concentration (e.g., venlafaxine) was degraded after 90 min, while 20CNSTO presented lower photocatalytic performance. Furthermore, some compounds were sporadically detected (e.g., fluoxetine) or their concentrations remained stable during the photocatalytic treatment time period (e.g., trimethoprim). In total 11 transformation products (TPs) were formed along the degradation processes and were identified by using liquid chromatography high resolution mass spectrometry.

Assessment of multiclass pharmaceutical active compounds (PhACs) in hospital WWTP influent and effluent samples by UHPLC-Orbitrap MS: Temporal variation, removals and environmental risk assessment

“…The WWTP applies a pretreatment (grit-removal), a flow equilibration tank, and a biological secondary treatment concluding with disinfection (addition of 15% solution NaClO). The Hydraulic RetentionTime (HRT) of the WWTP is 6 h, while the Solid Retention Time (SRT) in 1.5 day ( Konstas et al, 2019 ; Kosma et al, 2019 ). The plant discharges its effluent wastewater into the urban network which results into the municipal WWTP, thus the evaluation of its efficiency in order to predict final environmental loads has substantial interest.…”

“…Due to the numerous care activities performed in hospitals, hospital wastewater (HWW) constitutes a complex matrix with high loads of PhACs and metabolites, disinfectants, heavy metals, reagents etc. ( Frédéric and Yves, 2014 ; Konstas et al, 2019 ). These intensive and continuous activities lead to high concentrations of PhACs in HWW effluents, which sometimes are higher than in urban wastewaters ( Frédéric and Yves, 2014 ).…”

“…Moreover, in Europe, compounds such as diclofenac, ibuprofen, triclosan, sulfadimidine, carbamazepine and fluoxetine were reported in concentrations higher than the available ecotoxicity endpoints ( Fekadu et al, 2019 ). Being aware of the fact that information about the long-term and low-level exposure of PhACs is limited, potential threat to the aquatic environment and to humans is probable ( Konstas et al, 2019 ; Krakkó et al, 2019 ).…”

Exploring the Efficiency of UHPLC-Orbitrap MS for the Determination of 20 Pharmaceuticals and Acesulfame K in Hospital and Urban Wastewaters with the Aid of FPSE

“…Domestic, industrial wastes, and rain waters are obtained from the WWTP-U, often surpassing the WWTP's capacity to deal with this amount. WWTP-U also receives hospital effluents, therefore the occurrence of pharmaceutical compounds in both plants has a significant interest [54].…”

<p>Differentiation Between Metronidazole Residues Disposal by Using Adsorption and Photodegradation Processes Onto MgO Nanoparticles</p>

“…25,26 Heterogeneous photodegradation is widely used on a large scale for removing the persistent organic pollutants from aqueous solutions through their simplicity in design, extremely regeneration potential, free sludge operation, and low cost. 27 There are various catalytic materials including nano-sized materials, 28,29 carbon nanotubes, and graphene oxide have been enhanced to eliminate organic compounds from aqueous solutions. 30,31 Recently, nanoparticles are a suitable option because of their large surface in order to complete chemical reactions and decay of organic pollutants.…”