Occurrence and distribution of organic corrosion inhibitors (OCIs) in riverine sediments from the Pearl River Delta, South China

Although soluble organic corrosion inhibitors (OCIs) have been observed globally in surface water, data on their exposures in sediments are still scarce. In this study, a comprehensive investigation on spatial variations and potential sources of OCIs were conducted in riverine sediments from the Pearl River Delta (PRD), one of the most developed and urbanized areas in China. Of 12 OCIs, 7 were detected with the total concentrations ranging from 81.8 to 401.2 ng/g. When the results were compared with those of the water phase, OCIs in the riverine sediments exhibited relatively low concentrations, which was likely due to their low K ow , and they were not expected to be adsorbed onto sediments. The spatial variation of OCIs suggested that the discharge of sewage treatment plants (STPs) effluent could be a major source of OCIs in the PRD region. The total concentrations of OCIs had a significant positive correlation with total organic carbon (TOC) contents, suggesting that they have similar sources. This study strongly indicated that the high consumption of OCIs have led to their wide exposure in different environments in the PRD region and additional ecotoxicological data are needed to evaluate their potential risks in riverine sediments in the future.