Comprehensive screening of quaternary ammonium surfactants and ionic liquids in wastewater effluents and lake sediments

Quaternary ammonium compounds (QACs) are widely used as surfactants and biocides and also comprise the cations in ionic liquids. QACs have the potential to reach the environment via household, agricultural, and industrial use, and it is important to understand the distribution and sources of these compounds in aquatic systems. In this study, QACs were found in both wastewater effluents and sediments, with compounds containing twelve or more carbons in the side-chain being more prevalent in both matrices. Data from wastewater treatment plants with different unit operations and from sediment cores point to wastewater treatment practices and usage rates being important factors in dictating the environmental prevalence of QACs.