Effect of Ethylenediamine-N, N′-disuccinic acid (EDDS) on the speciation and bioavailability of Fe2+ in the presence of sulfide in anaerobic digestion. (April 2017)

• Record Type: Journal Article
• Authors: Thanh, Pham Minh; Ketheesan, Balachandran; Yan, Zhou; Stuckey, David
• Is Part Of: Bioresource technology. Volume 229(2017)
• Page Start: 169
• Page End: 179
• Publication Date: 2017-04
• Subjects: Chelating agent -- Metal speciation -- Metal bioavailability -- Sulfide -- Anaerobic digestion; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.12.113
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Speciation and bioavailability of Fe 2+ was determined at steady state conditions. Sulfide precipitated Fe 2+ as FeS and hence reduced the performance of the SAMBR. EDDS was able to compete with sulfide and improve Fe 2+ bioavailability in a SAMBR. Abstract: The effects of a biodegradable chelating agent, Ethylenediamine-N, N′-disuccinic acid (EDDS), on the speciation and bioavailability of iron (Fe 2+ ) in anaerobic digestion were examined. Fe 2+ supplementation at 10 mg/L increased methane yield, but the presence of 8 mg/L sulfide led to the precipitation of Fe 2+ as FeS which limited its bioavailability. The results confirmed that the EDDS could replace common chelating agents with low biodegradability (EDTA and NTA), and improve the bioavailability of Fe 2+ by forming an Fe-EDDS complex, thereby protecting Fe 2+ from sulfide precipitation. Experimental findings from sequential extraction using the Community Bureau of Reference (BCR) method, and quantification of free EDDS and Fe-EDDS complex using UHPLC, confirmed that 29.82% of Fe 2+ was present in bioavailable forms, i.e. soluble and exchangeable, when EDDS was added at 1:1 molar ratio to Fe 2+ . As a result, the methane production rate increased by 11.17%, and the methane yield increased by 13.25%.