Ezebuiro, Nwagbo ChristpeaceNwagbo ChristpeaceEzebuiroKörner, InaInaKörner2020-01-202020-01-202016-11-15Journal of Environmental Chemical Engineering 1 (5): 341-351 (2017)http://hdl.handle.net/11420/4413Anaerobic digestion (AD2) is a well-known pathway in bioenergy production but it could become more efficient. There is a poor understanding of the impacts of trace elements (TEs3) on substrate hydrolysis, which is a limiting step for energy production during AD. Hence, selected substrates were analysed for determining the TEs contents and other properties that are connected with TEs activities. The results showed a wide variation in TEs concentration, and also suggest that the TEs composition may be unfavourable for an optimum substrate hydrolysis. Therefore, AD investigations were carried-out using 1-L glass reactors in mesophilic batch mode with a maize silage-based feedstock (MSF4) as an exemplary AD substrate. The experimental set-up was based on a factorial design with Ni, Co, Se, Mo and VFA as factors and hydrolysis and acidification rate (HAR5) as response. The objectives were to qualitatively evaluate the influences of substrate characteristics on HAR, to determine the main and interaction effects of TEs and VFA concentrations on HAR and to optimise TEs configuration at different VFA levels. The response surface model and the desirability function were applied for data analyses. Certain Ni and Mo concentrations as well as the VFA∗Mo interaction improved HAR at VFA levels of 10 and 120 mmol/L. At VFA levels ≥ 200 mmol/L, Co∗Se interaction was significantly beneficial, while Co∗Mo interaction significantly decreased the HAR. In conclusion, TEs supplementation can enhance substrate HAR during AD but the efficiency will depend on the process VFA concentration.en2213-343720161341351Elsevieracidificationanaerobic digestioncobaltfactor interactionshydrolysismolybdenumnickelseleniumvolatile fatty acidsNaturwissenschaftenJournal Article10.1016/j.jece.2016.11.032Other