Source characterization of nervous system active pharmaceutical ingredients in healthcare facility wastewaters

Nervous system active pharmaceutical ingredients (APIs), including anti-depressants and opioids, are important clinically administered pharmaceuticals within healthcare facilities. This study provides source characterization data describing the composition and magnitude of nervous system APIs present in healthcare facility wastewaters. Concentrations and mass loadings of ten nervous system APIs and three nervous system API metabolites are reported for wastewaters from a hospital, nursing, assisted living, and independent living facility within a single municipality. Concentrations of nervous system APIs ranged from non-detectable levels for alprazolam in all four facility wastewaters to a high of 290 ng/L amitriptyline in nursing facility wastewater. The summed mean concentration of all thirteen analytes ranged from 402 ng/L in independent living facility wastewater to 624 ng/L in assisted living facility wastewater. Wastewater flow rates from each facility were combined with concentration data to estimate the daily mass loading of nervous system APIs leaving each facility through wastewater discharge to the municipal sewer system. The total mass loading of all thirteen analytes for the hospital, nursing, assisted living, and independent living facility was 228, 44, 29.5, and 28.1 mg/day, respectively. The total mass loading of nervous system APIs contributed to the municipality's wastewater from all four facilities was 330 mg/day.     

Advanced oxidation of alkylphenol ethoxylates in aqueous systems

Alkylphenols and alkylphenol ethoxylates are ubiquitous wastewater contaminants. In this study the oxidation of nonylphenol ethoxylates (NPEO) and octylphenol ethoxylates (OPEO) by oxidant systems generating hydroxide radicals was evaluated. The reaction of each oxidant with a technical mixture of NPEO (Tergitol™) and OPEO (Triton X-100™) in ultrapure laboratory water and four aqueous environmental matrices was carried out in order to develop an understanding of reaction kinetics. The oxidation of APEOs was evaluated by hydroxyl radical generated by (1) hydrogen peroxide in the presence of ultraviolet light, (2) Fenton’s reagent, and (3) a photo-Fenton’s process. The second order kinetic rate constant for both NPEO and OPEO with hydroxyl radical was calculated to be 1.1 × 10¹⁰ M⁻¹ s⁻¹. The efficacy of the AOPs within an aqueous environmental matrix was dependent on the rate of formation of hydroxyl radical and the scavenging capacity of the matrix. A model based on the hydroxyl radical formation, scavenging capacity and the kinetic rate constant of target APEO was developed from the existing literature and applied to predict the concentration of APEOs in solution during advanced oxidation in different aqueous environmental matrices.     

Healthcare facility effluents as point sources of select pharmaceuticals to municipal wastewater

Effluents from four healthcare facilities were characterized for the concentration of 16 common active pharmaceutical ingredients. The sampled facilities included a hospital, nursing care, assisted living, and independent living facility located within a single municipal wastewater system in Texas. Eleven of the 16 monitored pharmaceuticals were detected in at least 1 healthcare facility effluent and 2 measured antibiotics (sulfamethoxazole and trimethoprim) were detected in all 4 facility effluents. Active pharmaceutical ingredient concentrations ranged from non-detectable levels for several corticosteroids in all facility effluents to 180 microg/L sulfamethoxazole in the nursing care wastewater effluent. The mass of active pharmaceutical ingredients discharged to the municipality's wastewater conveyance system was determined by combining individual facility concentration data and daily wastewater flow. The estimated daily mass loading of all 16 pharmaceuticals ranged from 0.16 g/day to 23 g/day in the assisted living facility and nursing wastewater effluents, respectively. The combined active pharmaceutical ingredient mass loading for all four facilities was 42.6 g/day. These findings provide source characterization data for 16 common pharmaceuticals in healthcare facility wastewater and provide a basis for risk assessment of pharmaceuticals present in healthcare facility wastewaters.