US EPA

4960990 

Journal Article 

Degradation pathway of the photochemical oxidation of ethylenediaminetetraacetate (EDTA) in the UV/H2O2-process 

Sorensen, M; Zurell, S; Frimmel, FH 

1998 

Yes 

Acta Hydrochimica et Hydrobiologica
ISSN: 0323-4320
EISSN: 1521-401X 

26 

2 

109-115 

WOS:000072809200006 

The degradation pathway for the oxidation of EDTA in the UV/H2O2-process was investigated. In absence of iron ions, the mineralization of EDTA is dominated by the reaction of the HO-radicals generated by the photolysis of H2O2. The organic degradation products iminodiacetate (IMDA), glycinate, oxamate, glyoxylate, oxalate and formate, and the inorganic degradation products carbon dioxide, ammonia, nitrate, nitrite, and cyanate were found. In the presence of iron ions, photolytic decarboxylation processes inside the complex get an important role during degradation, and the organic degradation products ethylenediaminetriacetate (ED3A), ethylenediaminediacetate (EDDA), ethylenediaminemonoacetate (EDMA) were also found. By combining product studies with balances of carbon and nitrogen, the degradation pathway in the UV/H2O2-process could be elucidated. The degradation of EDTA was fast (k(deg) = 0.012 s(-1)), and no toxic degradation products were identified. Therefore, the process is well suited for the elimination of EDTA in water treatment. 

EDTA; degradation products; UV/H2O2-process; HO-radicals; mercury low-pressure lamp; advanced oxidation process