Effect of bioaugmentation on digestate metal concentrations in anaerobic digestion of sewage sludge

Abstract

This study examined the influence of bioaugmentation on metal concentrations (aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel and zinc) in anaerobically digested sewage sludge. To improve the digestion efficiency, bioaugmentation with a mixture of wild-living Archaea and Bacteria (MAB) from Yellowstone National Park, USA, was used. The total concentration of all metals was higher in the digestate than in the feedstock. During anaerobic digestion, the percent increase in the concentration of most of metals was slightly higher in the bioaugmented runs than in the un-augmented runs, but these differences were not statistically significant. However, the percent increase in cadmium and cobalt concentration was significantly higher in the bioaugmented runs than in the un-augmented runs. At MAB doses of 9 and 13% v/v, cadmium concentration in the digestate was 211 and 308% higher than in the feedstock, respectively, and cobalt concentration was 138 and 165%, respectively. Bioaugmentation increased over 4 times the percentage of Pseudomonas sp. in the biomass that are able to efficiently accumulate metals by both extracellular adsorption and intracellular uptake. Biogas production was not affected by the increased metal concentrations. In conclusion, bioaugmentation increased the concentration of metals in dry sludge, which means that it could potentially have negative effects on the environment.

Optimization of the Process of Methane Production From Wheat Straw and Bovine Manure Co-Digestion by Ultrasound Disintegration and Physicochemical Treatments

“…In the third step (7 th -10 th ), the TA stabilization occurs and final values were around 13.6 g/L and 18.8 g/L for BM and SS respectively, indicating that the AD process already reached stability. These results conform with those observed by Montusiewicz et al [27]. Based on the results obtained above that showed significant inhibition of AD due to the high concentration of Cu and Zn in SS, we maintained BM as inoculum for the rest of the study.…”

“…Heavy metals (HM) are present in municipal sludge in significant concentrations and the most frequently found are copper (Cu), zinc (Zn), lead (Pb), iron (Fe), and nickel (Ni) [27][28]. The industry is the primary source of HM in urban wastewater (UWW) and represents up to 50 % of the total HM content in SS [29].…”

Effect of Acid Whey Addition for Sewage Sludge Co-Digestion on the Nitrogen and Phosphorus Release

“…Comparing the results with the data in the literature, the removal efficiency obtained was usually lower, reaching up to 10-20% [Möller and Müller, 2012;Montusiewicz et al, 2013;Montusiewicz, 2015]. Massé et al [2007] obtained 25.5% retention of phosphorus during AD of swine manure, while in the anaerobically digested pig slurry 36% of P losses was indicated [Marcato et al 2008].…”

“…1b). As a result of fermentation, a significant increase in the ammonium concentration was achieved in the digestate in all runs, which was the effect of ammonification [Montusiewicz, 2015]. Compared to SS, slightly lower ammonium nitrogen concentration in the digestate was recorded, by 14.5 and 13.8 %, respectively (run 1.2 and 2.2).…”

Operational process stability in pilot dry anaerobic digester of source‐sorted organic fraction municipal solid waste

“…53 Trace elements in parts of central ligands of the essential enzymes that initiate several anaerobic processes and a component of bacterial nucleic acid required for vitamin synthesis. 54 Metal can be taken up in complexes such as co-citrate or bound to siderophores. Their form, whether as free ions, complex bound, or precipitates, depends on various parameters, such as pH, alkalinity, and the presence of sulfuric compounds and excreted soluble microbial products.…”