Pollution and ecological risk of heavy metals and arsenic in in road-deposited sediment and rainfall runoff of a coal port in Northern China.

Coastal ports are important areas for national economic growth. However, due to human activity and ongoing port development, heavy metals (HMs) and arsenic (As) have increased in the road-deposited sediment (RDS) and runoff of port roads, posing a threat to the environment and ecology. This study focused on a representative coal port in northern China to assess the characterization on occurrence and ecological risk of HMs (Zn, Ni, Cr, Cu, Pb, Cd, and Hg) and As in RDS and runoff in three typical functional areas, including office, storage yard, and dock. Particulate and dissolved HMs and As were determined, and the Zn of RDS was particularly prominent, as well as loading of up to 0.472.85 mg/m. The largest loading of Zn, Ni, Cr, Cu, Pb, Cd and As were all found in the particle size range of 0.0010.075 mm among different particle size fractions. The results of Potential Ecological Risk Index (RI) showed that the storage yard area showed the highest ecological risk of HMs, including Zn (14.03), Cd (205.07), As (88.1) and Hg (84.48). In addition, it was confirmed that Zn, Cr and Cu were the primarily polluted HMs in port runoff, while the runoff had the greatest mass load of HMs and As in the dock area with the highest Nemerow index method of 4.77. The obtained findings provided a significant scientific basis to understand the non-point source of HMs and As in RDS and rainfall runoff in different typical functional areas of a coal port.