A longitudinal study of mass loads of quaternary ammonium compounds in sludge associated with COVID-19 Stringency Index indicators in Beijing, China
Thapa B, Sapkota S, Chen J, Zunong J, Asihaer Y, Khattab N, Li M, Ding D, Vermund S, Shu M, Hu Y. A longitudinal study of mass loads of quaternary ammonium compounds in sludge associated with COVID-19 Stringency Index indicators in Beijing, China. Environmental Chemistry And Ecotoxicology 2025, 7: 39-49. DOI: 10.1016/j.enceco.2024.10.004.Peer-Reviewed Original ResearchDialkyldimethylammonium chlorideWastewater treatment plantsTreatment plantsContainment policiesQuaternary ammonium compoundsSludge specimensChromatography-tandem mass spectrometryCOVID-19 containment policiesLiquid chromatography-tandem mass spectrometryWorkplace closuresSBACSludgeBackward estimationIncreasing trendQuaternary ammonium compounds' concentration