Enhanced Anaerobic Digestion of Food Waste by Supplementing Trace Elements: Role of Selenium (VI) and Iron (II)

Abstract

This paper discusses the potential to enhance the anaerobic digestion of food waste FW by supplementing trace elements (Fe, Co, Ni, Zn, Mn, Cu, Se, and Mo) individually as well as in cocktails. A series of batch experiments on the biomethane potential of synthetic food waste were performed with low (FW-A) and high (FW-B) trace element background concentrations prepared in, respectively, Delft (The Netherlands) and Tampa (Florida, USA). The most effective trace elements for FW-A were Fe with an increase of 39.2 (±0.6)% of biomethane production, followed by Se (34.1 ± 5.6% increase), Ni (26.4 ± 0.2% increase) and Co (23.8 ± 0.2% increase). For FW-B supplementing these trace elements did not result in enhancement of the biomethane production, except for Se. FW-B had a Se concentration of 1.3 (±0. 5) µ g/gTS, while it was below the detection limit for FW-A. Regardless of the FW source, Se resulted in 30-35% increase of biomethane production at a concentration range of 25-50 µg/L (0.32-0.63 µM). Volatile fatty acids analysis revealed that TE supplementation enhances their consumption, thus yielding a higher biomethane production. Moreover, additional experiments on sulfide inhibition showed the enhancing effects of trace elements on the anaerobic digestion of food waste were not related with sulfide toxicity, but with the enzymatic reactions and/or microbial biomass aggregation.

Screening of trace metal supplementation for black water anaerobic digestion

“…The model estimates that by supplementing the media with these metals, the SMA can be improved to values over 12 mLCH 4 .gCOD -1 .d -1 ( Figure 3B). Ariunbaatar et al (2016) verified an increase of 30-35% in CH 4 formation by adding 25-50 μg/L of Se. These authors reported that supplementation of Se resulted in a decrease of acetic and propionic acids in the batch assays.…”

Identification of Critical Problems in Biochemical Methane Potential (BMP) Tests From Methane Production Curves

“…Measurement of biochemical methane potential (BMP) of organic substrates is important for research (Ariunbaatar et al, 2016;Yeshanew et al, 2016;Benn and Zitomer, 2018;Hafner et al, 2018;Filer et al, 2019) and biogas plant management (Koch et al, 2016;Gandiglio et al, 2017;Lippert et al, 2018). In contrast to nearly all chemical parameters (e.g., pH value and the chemical oxygen demand), and other biochemical parameters (e.g., biochemical oxygen demand), there is no standard method available for BMP tests (Baird et al, 2017).…”

Dry Anaerobic Digestion of Food and Paper Industry Wastes at Different Solid Contents

“…Organic wastes from municipalities, agricultural and industrial activities degrade over a period of time, having a negative impact on the environment [1]. Landfilling of these wastes is still the most common practice in the world [2], resulting in pollution of water and soil with leachate, and air with emission of methane and other greenhouse gases [3,4]. Anaerobic digestion to produce biomethane has been a successful treatment option for these wastes; it is effective in solving environmental, health and energy challenges [3][4][5].…”

“…Landfilling of these wastes is still the most common practice in the world [2], resulting in pollution of water and soil with leachate, and air with emission of methane and other greenhouse gases [3,4]. Anaerobic digestion to produce biomethane has been a successful treatment option for these wastes; it is effective in solving environmental, health and energy challenges [3][4][5]. Additionally, the digestate residues from biogas plants are rich in macro-and micronutrients and also contain phosphorus and ammonium nitrogen [6], which make them suitable as biofertilizers [7].…”