Attenuation of Wastewater-Derived Contaminants in an Effluent-Dominated River

Abstract

Although wastewater-derived chemical contaminants undergo transformation through a variety of mechanisms, the relative importance of processes such as biotransformation and photolysis is poorly understood under conditions representative of large rivers. To assess attenuation rates under conditions encountered in such systems, samples from the Trinity River were analyzed for a suite of wastewater-derived contaminants during a period when wastewater effluent accounted for nearly the entire flow of the river over a travel time of approximately 2 weeks. While the concentration of total adsorbable organic iodide, a surrogate for recalcitrant X-ray phase contrast media in wastewater, was approximately constant throughout the river, concentrations of ethylenediamine tetraacetate, gemfibrozil, ibuprofen, metoprolol, and naproxen all decreased between 60% and 90% as the water flowed downstream. Comparison of attenuation rates estimated in the river with rates measured in laboratory-scale microcosms suggests that biotransformation was more important than photolysis for most of the compounds. Further evidence for biotransformation in the river was provided by measurements of the enantiomeric fraction of metoprolol, which showed a gradual decrease as the water moved downstream. Results of this study indicate that natural attenuation can result in significant decreases in concentrations of wastewater-derived contaminants in large rivers.

Occurrence and in-stream attenuation of wastewater-derived pharmaceuticals in Iberian rivers

“…The in-stream attenuation rates for pharmaceuticals reported in our study were similar to those reported in the literature (Fono et al 2006;Joss et al 2006;Lin et al 2006;Writer et al 2013). Our half-life times were comparable to those reported in a Californian stream (Lin et al 2006), in a 300 km stretch of a river in Texas (Fono et al 2006), or in a 5.4 km reach of Boulder creek in Colorado (Writer et al 2013).…”

“…Our half-life times were comparable to those reported in a Californian stream (Lin et al 2006), in a 300 km stretch of a river in Texas (Fono et al 2006), or in a 5.4 km reach of Boulder creek in Colorado (Writer et al 2013). In those studies, half-life times of ibuprofen were 2.7 and 4.6 h respectively, whereas in our study it averaged 2.01 ± 1.17 h. In the case of the Californian stream, the half-life times of ibuprofen, naproxen and gemfibrozil (2.4 -4.6 h) were similar to those observed in our study segments (Table 2).…”

Enantiomeric fraction evaluation of pharmaceuticals in environmental matrices by liquid chromatography-tandem mass spectrometry

“…2). PHO and MET enantiomers were already found in WWTP effluents at quantifiable concentrations [10,[22][23][24]28,29,49]. Both the metabolite NFLX and the beta 2 -agonist SBT were not found in any of the analysed WWTP.…”

“…Some classes of CP, such as proton pump inhibitors [15,16], antifungals [17], Non Steroid Anti-Inflammatory Drugs (NSAID) [18][19][20][21], beta-blockers [10,12,[22][23][24][25][26][27][28][29][30][31] as well as antidepressants and their metabolites [11][12][13][28][29][30][31][32][33][34], have been reported in environmental matrices, concerning its enantiomers. Regarding antidepressants, enantioselective biodegradation of venlafaxine (VNF) was found in a French river, with racemic VNF at the output of the main WWTP discharging into the river and with EF variation along the river stretch [11].…”

Hardness Removal by Freezing with a Dry Gas

“…Water reuse has been used to provide water for uses such as irrigation, power plant cooling water, industrial process water, and groundwater recharge and has been accepted as a method for indirect drinking water production [6][7][8]. Desalination has become an important source of drinking water production, with thermal desalination processes developing over the past 60 years and membrane processes developing over the past 40 years [9].…”