title: Occurrence, distribution, and potential affecting factors of organophosphate flame retardants in sewage sludge of wastewater treatment plants in Henan Province, Central China.
abstract: Organophosphate esters (OPEs) are widely used as flame retardants. In this study, the occurrence and distribution of six OPEs were investigated in sewage sludge from 24 wastewater treatment plants (WWTPs) in 18 cities of Henan province, Central China. The results indicated that all target OPEs were detected in the sludge samples with the detection rate of 95.8%, except tris(dichloropropyl)phosphate (TDCP). The total concentration of the six OPEs ranged from 38.6 to 508 μg kg(-1). Tris(2-chloroethyl)phosphate (TCEP), tris(2-butoxyethyl)phosphate (TBEP), and tris(2-chloroiso-propyl)phosphate (TCPP) were found to be predominant, with concentrations ranging from 2.50 to 203, 1.60 to 383, and 6.70-161 μg kg(-1), respectively. The potential factors affecting OPE levels in sewage sludge, such as wastewater source, sludge characteristics, operational conditions, treatment techniques, and total organic carbon (TOC) of sludge in WWTPs were investigated. The results indicated that the total concentration of OPEs in sewage sludge has no significant relationship with the individual parameters (p > 0.05). However, significant correlations were found between triphenyl phosphate (TPhP) level and treatment capacity (R = 0.484, p < 0.05), processing volume (R = 0.495, p < 0.05), and serving population (R = 0.591, p < 0.05). Furthermore, the relationship between treatment techniques and the total concentration of OPEs in sewage sludge was also investigated in this study, and the results illustrated that the levels of OPEs in sludge were independent of the solid retention time (SRT).
authors.affiliation: Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450001, People's Republic of China; Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou, Henan 450001, People's Republic of China. Electronic address: lpang@zzuli.edu.cn.
authors.forename: Long
authors.initials: L
authors.lastname: Pang
authors.affiliation: Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450001, People's Republic of China.
authors.forename: Yiting
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450001, People's Republic of China.
authors.forename: Han
authors.initials: H
authors.lastname: He
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, People's Republic of China.
authors.forename: Kang
authors.initials: K
authors.lastname: Liang
authors.affiliation: Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450001, People's Republic of China; Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou, Henan 450001, People's Republic of China.
authors.forename: Hongzhong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou, Henan 450001, People's Republic of China. Electronic address: zjh@zzuli.edu.cn.
authors.forename: Jihong
authors.initials: J
authors.lastname: Zhao
mesh_terms: D002681:China; D005411:Flame Retardants / Q000032:analysis*; D010755:Organophosphates / Q000032:analysis*; D012722:Sewage / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D005411:Flame Retardants; D010755:Organophosphates; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Organophosphate flame retardants; Sewage sludge; Wastewater treatment plant