Biodegradable chelating agents for industrial, domestic, and agricultural applications—a review

Abstract

Aminopolycarboxylates, like ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), are chelating agents widely used in several industrial, agricultural, and domestic applications. However, the fact that they are not biodegradable leads to the presence of considerable amounts in aquatic systems, with serious environmental consequences. The replacement of these compounds by biodegradable alternatives has been the object of study in the last three decades. This paper reviews the most relevant studies towards the use of environmentally friendly chelating agents in a large number of applications: oxidative bleaching, detergents and cleaning compositions, scale prevention and reduction, remediation of soils, agriculture, electroplating, waste treatment, and biocides. Nitrilotriacetic acid (NTA), ethylenediaminedisuccinic acid (EDDS), and iminodisuccinic acid (IDS) are the most commonly suggested to replace the nonbiodegradable chelating agents. Depending on the application, the requirements for metal complexation might differ. Metal chelation ability of the most promising compounds [NTA, EDDS, IDS, methylglycinediacetic acid (MGDA), L-glutamic acid N,N-diacetic acid (GLDA), ethylenediamine-N,N'-diglutaric acid (EDDG), ethylenediamine-N,N'-dimalonic acid (EDDM), 3-hydroxy-2,2-iminodisuccinic acid (HIDS), 2-hydroxyethyliminodiacetic acid (HEIDA), pyridine-2,6-dicarboxylic acid (PDA)] with Fe, Mn, Cu, Pb, Cd, Zn, Ca, and Mg was simulated by computer calculations. The advantages or disadvantages of each compound for the most important applications were discussed.

Enhanced anaerobic digestion of food waste by trace metal elements supplementation and reduced metals dosage by green chelating agent [S, S]-EDDS via improving metals bioavailability

“…Control (without metals supplementation) 372 ± 8 e 25% of optimal dosage 424 ± 11 14.0 ± 0.5 25% of optimal dosage þ EDDS 453 ± 14 21.8 ± 0.8 50% of optimal dosage 446 ± 16 19.9 ± 0.7 50% of optimal dosage þ EDDS 498 ± 16 33.9 ± 0.9 75% of optimal dosage 473 ± 21 27.2 ± 0.7 75% of optimal dosage þ EDDS 506 ± 19 36.0 ± 1.3 100% of optimal dosage 504 ± 18 35.5 ± 1.2 100% of optimal dosage þ EDDS 496 ± 19 33.3 ± 1.0 200% of optimal dosage 487 ± 14 30.9 ± 0.8 used for indirectly indicating the methanogenic activity of anaerobic sludge (Dong et al, 2010;Kida et al, 2001;Qing-Hao et al, 2008). Fig.…”

“…The chemical speciation of metals changes during complex chemical or biochemical reactions such as the precipitation withS 2À , CO 3 2À , PO 4 3À and the formation of inorganic and organic complexes, which might make metals not directly bioavailable and raise the cost of metals additive. The metals bound to chelating agent is reported as a feasible method to improve metals bioavailability to anaerobe via forming dissolved complexes and preventing metals precipitation (Hu et al, 2008a(Hu et al, , 2008bQing-Hao et al, 2008;Vintiloiu et al, 2013). Vintiloiu et al (2013) suggested that ethylenediaminetetraacetic acid (EDTA) could increase the solubility and bioavailability of essential metals, therefore enhance the methane production.…”

“…The human health risk of NTA should therefore be taken into consideration. Ethylenediamine-N,N'-disuccinic acid ([S, S]-EDDS), a structural isomer of EDTA, is regard as a green chelating agent with an excellent biodegradability and a low environmental risk (Kołody nska, 2011;Pinto et al, 2014). EDDS has a high metals chelation ability, which is almost comparable to that of EDTA .…”

Induced Plant Accumulation of Lithium

“…EDTA has been used in several induced metal accumulation studies. The addition of EDTA to Pb spiked soil has been shown to increase the Pb content in Canavalia ensiformis and Helianthus annuus plants significantly [53,54]. Alternatively, a weak extraction of Pb using EDDS has been noted several times [35].…”

An Interaction of Rhamnolipids with Cu2+ Ions

“…The results obtained for MGDA and EDTA correspond to the literature data. The theoretical chemical simulations, which were performed at a 1:5 metal to chelating agent molar ratio, showed that at least 80% of Cu 2+ should be complexed by these compounds at a pH ranging from about 1.5 to 10.0 [27]. …”