Systematic Evaluation of the In-Sample Stability of Selected Pharmaceuticals, Illicit Drugs, and Their Metabolites in Wastewater

Abstract

The in-sample stability of selected pharmaceuticals, illicit drugs, and their metabolites in wastewater was assessed under six different conditionsuntreated, addition of hydrochloric acid or sodium metabisulfite solution, combined with or without sterile filtration, and at four representative temperatures, at 35 °C for up to 28 days, 22 °C for 56 days, and 4 °C and −20 °C for 196 days, or freeze/thaw cycles for 24 weeks. Paracetamol, 6-monoacetylmorphine, morphine, and cocaine were poorly stable in untreated wastewatere.g., with 50% transformation within 1.2−8.1 days at 22 °C, and acidification reduced their in-sample transformations. Acesulfame, carbamazepine, cotinine, methamphetamine, 3,4methylenedioxy-methamphetamine (MDMA), ketamine, norfentanyl, 3,4-methylenedioxy-N-ethylamphetamine (MDEA), and norbuprenorphine were highly or moderately stable over the observed period, even in untreated wastewater. Fitting of pseudofirst-order kinetics and the Arrhenius equation was used to develop a multistage transformation estimation model combined with an interactive tool to evaluate possible transformation scenarios of selected biomarkers for the processes from sampling to preanalysis. However, as the wastewater composition can vary between sites and over time, the variability of in-sample stability requires further exploration.

Sources of Aerosol Acidity at a Suburban Site of Nanjing and Their Associations with Chlorophyll Depletion

“…For all of the tested samples, the levels of chlorophyll a reached steady state with time (∼60 h) after a 24 h exposure. This result implied that the degradation rate of chlorophyll a was close to 0 after a 24 h exposure to PM 2.5 water sample extracts …”

“…This result implied that the degradation rate of chlorophyll a was close to 0 after a 24 h exposure to PM 2.5 water sample extracts. 59 For the 24 h exposure time, the average degradation rates of chlorophyll a varied across water-extracted samples of PM 2.5 collected on different dates. The average degradation rates of chlorophyll a ranged from 0.001 to 0.02 mg L −1 h −1 at 25 ± 5 °C under the humidity of 35 ± 5% for 24 h (Figure 2B).…”

Quantitative Determination and Environmental Risk Assessment of 102 Chemicals of Emerging Concern in Wastewater-Impacted Rivers Using Rapid Direct-Injection Liquid Chromatography—Tandem Mass Spectrometry

“…Samples were transferred to an ice-cold thermal bag and then frozen at −20 • C as soon as possible. This has generally been shown to preserve analyte stability [21,22]. However, no pH adjustment could be made prior to freezing at site, and some degree of microbial transformation could not be ruled out, though this would likely be low given that analysis was performed within only 2-3 weeks after sampling.…”

Accurate Removal of Toxic Organic Pollutants from Complex Water Matrices

“…However, the global occurrence of emerging toxic organic pollutants in water has raised concerns about serious adverse effects on aquatic ecosystems and human health. , Toxic organic pollutants are distributed in various water matrices, and some of them are persistent in aquatic environments and resistant to regular treatment technologies. − In addition, the toxic thresholds of these pollutants are extremely low, thus leading to high risk due to potential aquatic toxicity, endocrine disrupting activity, and genetic toxicity, even though their concentrations range from only 10 –9 ∼ 10 –12 mol L –1 . − An increasing number of studies on the fate of toxic organic pollutants warn of insufficient removal of toxic organic pollutants during traditional water and wastewater treatments, although the general indicators like COD and total organic carbon (TOC) can be readily reduced from 10 3 ∼ 10 4 mg L –1 to only several or tens of mg L –1 . Trace toxic organic pollutants are still repeatedly detected in typical water matrices such as secondary effluents, surface water, groundwater and even tap water. ,− Unfortunately, while toxic organic pollutants may only constitute a small portion of the COD and TOC, they contribute major toxicity. In addition to the development of conventional treatments for traditional water quality indices such as COD, future challenges and development directions in environmental science and technology for upcoming decades should be proposed as further risk controls for those characteristic pollutants in a targeted manner.…”