Molecular-Level Insights into Recalcitrant Ozonation Products from Effluent Organic Matter.

Wastewater ozonation is commonly employed to enhance the subsequent biodegradation of effluent organic matter (EfOM) and contaminants of concern. However, there is evidence suggesting the formation of recalcitrant ozonation products (OPs) from EfOM. To investigate the biodegradability of OPs we conducted batch biodegradation experiments using wastewater effluent ozonated with mass-labeled (O) ozone.

Ozonation of Gabapentin in Water─Investigating Reaction Kinetics and Transformation Mechanisms of a Primary Amine Using Isotopically Labeled Ozone.

Aliphatic amines are abundant micropollutants in wastewater treatment plant effluents. In order to mitigate such micropollutants, ozonation is one of the most commonly employed advanced treatment processes. Current research regarding ozone efficiency is heavily focusing on reaction mechanisms of different contaminant groups, including structures with amine moieties as reactive sites.

Isotopically labeled ozone: A new approach to elucidate the formation of ozonation products.

As ozonation becomes a widespread treatment for removal of chemicals of emerging concern from wastewater treatment plant effluents, there are increasing concerns regarding the formation of ozonation products (OPs), and their possible impacts on the aquatic environment and eventually human health. In this study, a novel method was developed that utilizes heavy oxygen (O) for the production of heavy ozone ([O]O, [O]O, [O]) to actively label OPs from oxygen transfer reactions. To establish and validate this new approach, venlafaxine with a well-described oxygen transfer reaction (tertiary amine -> N-oxide) was chosen as a model compound.

Stable isotope labeling for detection of ozonation byproducts in effluent organic matter with FT-ICR-MS.

Despite effluent organic matter (EfOM) being a major consumer of ozone during wastewater treatment, little is known about ozonation byproducts (OBPs) produced from EfOM. To unambiguously identify OBPs, heavy ozone was used to ozonate EfOM, resulting in O labeled and unlabeled OBPs. Labeled OBPs mostly represent a single O transfer and were classified as either direct or indirect OBPs based on the O/O intensity ratios of the isotopologues.