The removal of CAAs by iron with acid pretreatment was
carried out to investigate the role of corrosion coatings as shown in Fig. 6. The decreasing order of iron efficiency over 2 h
of reaction toward three CAAs was: iron with oxic corrosion
coatings > iron with anoxic corrosion coatings > fresh iron.
TCAA and DCAA could be partly removed by green rust as oxic
corrosion rather than by magnetite (Chun et al., 2005, 2007),
which might prove powerful reductants formed in oxic systems.