Multiple effects of nitrate amendment on the transport, transformation and bioavailability of antimony in a paddy soil-rice plant system.

•Kinetics of sb in paddy soil with adding nitrate was controlled multiple effects.•Proton consumption via denitrification could enhance Sb(V) mobility.•The redox cycling of fe and s could diversely affect sb availability.•Arsenite-oxidizing marker gene aoxB may be involved in Sb(III) oxidation.