Decomposition of nitrilotriacetate (NTA) in soils

The trisodium salt of nitrilotriacetic acid (NTA) has been proposed as a substitute for phosphate in detergents. The decomposition of this chelating agent in soils was studied by performing analyses for NTA and inorganic nitrogen after incubation of NTA-treated soils for various times. The results showed that NTA is readily decomposed by soil micro-organisms under aerobic or anaerobic conditions and that NTA-nitrogen is converted to nitrate under aerobic conditions. The latter finding indicates that use of detergents containing NTA may lead to nitrate enrichment of water resources.