Quaternary Pollutant

Quaternary pollutants are quaternary ammonium compounds (QACs), cationic surfactants with a positively charged nitrogen carrying four organic groups. They are used as disinfectants, fabric softeners, and preservatives, and their use rose sharply during the COVID-19 pandemic. QACs are an emerging contaminant of concern: they reach the sea through wastewater effluent and adsorb strongly to negatively charged particles, so they accumulate in estuarine and marine sediments. They are toxic to fish, daphnids, and algae, and their biocidal action can co-select for antibiotic resistance in sediment microbial communities.