In-situ immobilization of arsenic in the subsurface on an anthropogenic contaminated site
Due to its natural toxicity arsenic (As) has been used in many chemical warfare agents (CWA) during World War (WW) I and II. These CWA are on a cellular level more toxic than pure arsenic (Henriksson et al., 1996). CWA were used during WW I in combat and were merely produced during WW II. These compounds are persistent to these days in soil and groundwater (Haas et al., 1998). Decomposition products which are mainly analyzed in present groundwater are phenylarsonic acid, phenylarsine oxide and diphenylarsinic acid (Daus et al., 2008). These decomposition products mostly do not exhibit the high toxicity of the original compounds (Schneider et al., 2005). As containing substances were predominantly used in so-called “Blue Cross” CWA. The name is derived from the fact that substances with low volatility and high irritation potential were marked with a blue cross or ring (Martinetz, 1993). “Blue Cross” CWA containing As are e.g., adamsite, arsenic trichloride and Clark I.