Biodegradation Rate of EDTA and IDS and Their Metal Complexes

Abstract

Ethylenediaminetetraacetic acid (EDTA), when used as a main chelator for complex plant microfertilizers, causes many negative environmental effects; therefore, new compounds or new use of the known compounds to replace EDTA have been widely studied. In the present study, biodegradation rate, plant (Raphanus sativus) growth stimulation and ecotoxicity towards Daphnia magna and Chlorella vulgaris of iminodisuccinic acid (IDS), considered as an alternative for EDTA in agriculture, has been investigated. It was demonstrated that IDS’ biodegradation rate over 28 days was 28.1%, which is 4.5 times higher than that of EDTA. Similar to EDTA, complexation with metals led to an increase in the degradation rate by 1.8-fold. The majority of compounds were degraded within first 7 days. The GI values for IDS implemented at concentrations of 100 mg/L (both in pure form and in combination with microelements) were 2.4–2.6 times higher than those of EDTA. The ecotoxicity index EC10 of IDS was estimated to be 2.0 g/L and 5.8 g/L towards D. magna and Ch. vulgaris which are 4.1- and 10-fold higher than those for EDTA, respectively. It can be concluded that IDS is a promising agent to chelate microelements used in plant nutrition.

Glutamic-N,N-Diacetic Acid as an Innovative Chelating Agent in Microfertilizer Development: Biodegradability, Lettuce Growth Promotion, and Impact on Endospheric Bacterial Communities

“…rather than their mixtures. In our previous work [5], it was demonstrated that the degradation extent of a compositionally similar mixture of EDTAbased chelates (with Zn, Cu, Mn, and Fe) was approximately 14% over 28 days. Thus, the degradation extent of GLDA-based complexes determined in the current study was 4.3-fold higher.…”

“…Investigations indicate that EDTA and EDTA-based chelates exhibit remarkable resistance to biodegradation [4]. In particular, using a CO 2 evolution test, EDTA degradation rate was demonstrated to range between 6 and 10% within 28 days of incubation, and its complexes exhibited a degradation level of around 10-50% [5][6][7].…”