The biodegradability and treatability of NTA.

The use of trisodium nitrilotriace tate (NTA) in combination with poly phosphates has been found to be a useful detergency builder in the formulation of heavy-duty detergents. NTA does not by itself have all the necessary performance properties and, therefore, must be used in combina tion with the phosphates, rather than as a total substitute. As an ingredi ent in detergents, NTA becomes a com ponent of wastewater and, therefore, the biodegradability and the treatabil ity of NTA are of interest to the de tergent industry and to others con cerned with wastewater treatment and water supply. The research reported here has shown that NTA is biodegradable to natural end products, and that NTA would be removed in well-operated activated sludge wastewater treatment plants. No effect of NTA on primary or secondary settling, nor on sludge digestion has been observed. NTA en tering lakes and streams from treat ment plants having only primary treat ment, or NTA in untreated wastewater, would degrade readily. Pollard (1) has reported data which indicate that NTA is not toxic to hu mans and that at concentrations up to 100 mg/1 NTA, fish are not affected. Further, from the present work, it ap pears unlikely that NTA would be