{Reference Type}: Journal Article
{Title}: Arsenic species in soil profiles from chemical weapons (CWs) burial sites of China: Contamination characteristics, degradation process and migration mechanism.
{Author}: Ji C;Zhu Y;Zhao S;Zhang Y;Nie Y;Zhang H;Zhang H;Wang S;Zhou J;Zhao H;Liu X;
{Journal}: Chemosphere
{Volume}: 349
{Issue}: 0
{Year}: 2024 Feb 13
{Factor}: 8.943
{DOI}: 10.1016/j.chemosphere.2023.140938
{Abstract}: In this study, soil profiles and pore water from Japanese abandoned arsenic-containing chemical weapons (CWs) burial sites in Dunhua, China were analyzed to understand the distribution of arsenic (As) contamination, degradation, and migration processes. Results of As species analysis showed that the As-containing agents underwent degradation with an average rate of 87.55 ± 0.13%, producing inorganic pentavalent arsenic (As5+) and organic arsenic such as 2-chlorovinylarsonic acid (CVAOA), triphenylarsenic (TPA), and phenylarsine oxide (PAO). Organic arsenic pollutants accounted for 1.27-18.20% of soil As. In the vertical profiles, total As concentrations peaked at about 40-60 cm burial depth, and the surface agricultural soil exhibited moderate to heavy contamination level, whereas the contamination level was insignificant below 1 m, reflecting As migration was relatively limited throughout the soil profile. Sequential extraction showed Fe/Al-bound As was the predominant fraction, and poorly-crystalline Fe minerals adsorbed 33.23-73.13% of soil As. Oxygen-susceptible surface soil formed poorly-crystalline Fe3+ minerals, greatly reducing downward migration of arsenic. However, the reduction of oxidizing conditions below 2 m soil depth may promote As activity and require attention.