Organophosphate esters (OPEs) in wetland soil and Suaeda salsa from intertidal Laizhou Bay, North China: Levels, distribution, and soil-plant transfer model.

Wetlands have attracted much attention due to releases of organophosphate esters (OPEs) and other emerging contaminants into this particular environment. Here, Suaeda salsa plants and wetland soils collected from Laizhou Bay, North China, were analyzed to investigate the levels, distribution, and soil-plant transfer of OPEs in these ecosystems. The Σ18OPEs concentrations ranged from 137 to 386 ng/g dry weight (dw), whereas in rhizosphere the concentrations were between 99.8 and 198 ng/g dw. Suaeda salsa rhizosphere could promote the absorption of OPEs in wetlands, and Suaeda salsa root presents a greater rate of absorption. The Σ18OPEs concentrations ranged from 32.9 to 56.8 ng/g dw in roots, 3.93 to 7.51 ng/g dw in stems, and 2.79 to 4.06 ng/g dw in leaves. Log RCFs, log TFr-s and log TFs-l showed no significant correlations with their log KOW, indicating the complexity of uptake and translocation in the natural environment. Predictive model for the OPEs availability to Suaeda salsa was established from the experimental data. The field-based BCFs of all OPEs were dependent on KOW, decreased with increasing KOW. This study provides important insights into the phytoremediation potential of OPEs using Suaeda salsa as an effective strategy and their role in environmental risk assessment of OPEs in wetlands.