A study of phthalic acid esters (PAEs) in the municipal sludges of China

Six phthalic acid esters classified as U.S. EPA priority PAEs compounds, in eleven municipal sludges of China were studied with GC-MS. The total content of phthalic acid esters (∑PAEs) ranged from 10.465 to 114.166 mg/kg, mainly around 20mg/kg. PAEs with lighter molecular weight such as dimethyl phthalate (DMP), diethyl phthalate(DEP), di-n-butyl phthalate(DnBP), and butyl-benzyl phthalate(BBP) were detected in all the sludges, but their contents were generally less than 1.0mg/kg. Although di-n-octyl phthalate(DnOP) was not detected in some sludges, its contents were higher in others. di-(2-ethylhexyl) phthalate(DEHP) was detected in few sludges with lower content. Only individual PAEs compounds were predominant in each sludge, which exhibited different distribution characters. The types and contents of PAEs compounds in the sludges were related to the sources and treating methods of wastewater, sludge types, physical-chemical properties and the structures of PAEs compounds.