Assessment of organophosphate flame retardants in surface water and sediment from a freshwater environment (Yangtze River, China)

Organophosphate flame retardants (OPFRs) have been detected in the surface water, suspended sediments, and river sediments from the Yangtze River in China. A modified polar organic chemical integrative sampler (m-POCIS) was successfully used to quantify the OPFR concentrations in surface water. The OPFR concentrations estimated by the field m-POCIS at six sampling locations ranged from 8.99 to 112.45 ng/L with an average concentration of 47.04 ng/L. The OPFR concentrations in suspended sediments were related to the sediment particle size distribution. Chlorinated and alkyl OPFRs were the principle compounds in sediments, especially tris(2-chloroisopropyl) phosphate (TCPP) with concentrations of 3.37-29.65 ng/g. The relationship between the OPFR concentrations and total organic carbon (TOC) contents in sediments was examined. The results suggested that the OPFR concentrations were significantly correlated with the TOC contents. The primary OPFR transport mechanism in a freshwater environment occurs in surface water rather than sediment. This was evaluated by the logK(ow) and field sediment-water partition coefficient (logK(oc)) values between the sediment and water. Finally, the various distributions and transport of OPFRs at the sampling sites indicated that human activities, agricultural production, and wastewater effluents from sewage plants have an important effect on the OPFR levels in a freshwater environment.