Critical evaluation of monitoring strategy for the multi-residue determination of 90 chiral and achiral micropollutants in effluent wastewater

Bruce Petrie; Kathryn Proctor; Jane Youdan; Ruth Barden; Barbara Kasprzyk-Hordern

doi:10.1016/j.scitotenv.2016.11.059

Critical evaluation of monitoring strategy for the multi-residue determination of 90 chiral and achiral micropollutants in effluent wastewater

Sci Total Environ. 2017 Feb 1:579:569-578. doi: 10.1016/j.scitotenv.2016.11.059. Epub 2016 Nov 19.

Authors

Bruce Petrie¹, Kathryn Proctor¹, Jane Youdan², Ruth Barden², Barbara Kasprzyk-Hordern³

Affiliations

¹ Department of Chemistry, University of Bath, Bath BA2 7AY, UK; Water Innovation & Research Centre (WIRC), University of Bath, Bath, BA2 7AY Bath, UK.
² Wessex Water, Bath BA2 7WW, UK.
³ Department of Chemistry, University of Bath, Bath BA2 7AY, UK; Water Innovation & Research Centre (WIRC), University of Bath, Bath, BA2 7AY Bath, UK. Electronic address: b.kasprzyk-hordern@bath.ac.uk.

PMID: 27876391
DOI: 10.1016/j.scitotenv.2016.11.059

Abstract

It is essential to monitor the release of organic micropollutants from wastewater treatment plants (WWTPs) for developing environmental risk assessment and assessing compliance with legislative regulation. In this study the impact of sampling strategy on the quantitative determination of micropollutants in effluent wastewater was investigated. An extended list of 90 chiral and achiral micropollutants representing a broad range of biological and physico-chemical properties were studied simultaneously for the first time. During composite sample collection micropollutants can degrade resulting in the under-estimation of concentration. Cooling collected sub-samples to 4°C stabilised ≥81 of 90 micropollutants to acceptable levels (±20% of the initial concentration) in the studied effluents. However, achieving stability for all micropollutants will require an integrated approach to sample collection (i.e., multi-bottle sampling with more than one stabilisation method applied). Full-scale monitoring of effluent revealed time-paced composites attained similar information to volume-paced composites (influent wastewater requires a sampling mode responsive to flow variation). The option of monitoring effluent using time-paced composite samplers is advantageous as not all WWTPs have flow controlled samplers or suitable sites for deploying portable flow meters. There has been little research to date on the impact of monitoring strategy on the determination of chiral micropollutants at the enantiomeric level. Variability in wastewater flow results in a dynamic hydraulic retention time within the WWTP (and upstream sewerage system). Despite chiral micropollutants being susceptible to stereo-selective degradation, no diurnal variability in their enantiomeric distribution was observed. However, unused medication can be directly disposed into the sewer network creating short-term (e.g., daily) changes to their enantiomeric distribution. As enantio-specific toxicity is observed in the environment, similar resolution of enantio-selective analysis to more routinely applied achiral methods is needed throughout the monitoring period for accurate risk assessment.

Keywords: Chiral; Illicit drug; Personal care product; Pharmaceutical; Polypropylene; Sampling; Stability; Wastewater.