The Effects of Using Evogen Biogas Additive on the Microbiome and Performance of Full-Scale Biogas Plant

Biogas production from organic waste is a promising renewable energy source, but achieving optimal production and digester stability can be challenging. This study investigated the impact of the Evogen microbial additive on biogas production and digester status in two biogas plants (BG01 and BG02). Microbial abundance and physicochemical parameters were analyzed to assess the effects. The results show distinct microbial community shifts in Evogen-treated digesters, with increased abundance of methanogenic archaea and hydrolytic bacteria, indicating improved anaerobic digestion. Evogen supplementation positively influenced digester performance, as evidenced by higher alkalinity buffer capacity (FOS/TAC ratios), indicating enhanced acidification and methanogenesis, along with reductions in total solids and volatile solids, demonstrating improved organic matter degradation. Evogen-treated digesters exhibited significantly higher biogas production and improved process stability, as indicated by volatile fatty acids (VFAs) profiling. The dominance of Firmicutes, Synergistetes, Proteolytic Bacteroidetes and Actinobacteria highlighted their roles in substrate degradation and VFA production. The findings contribute to optimizing biogas production systems and understanding complex microbial interactions within anaerobic digesters. The addition of Evogen influenced microbial community composition and dynamics, potentially altering substrate utilization, metabolic interactions and overall community structure

Anaerobic Digestion Remediation in Three Full-Scale Biogas Plants through Supplement Additions

Additives can improve the efficiency of anaerobic digestion by increasing biogas production, reducing air pollution, and preventing ammonia inhibition. Biological or chemical supplementation can also improve the economic efficiency of anaerobic digestion. However, the effects of specific additives on biogas production can vary, depending on the type of supplement used. This research utilizes the additives on an industrial scale and monitors the optimization of the anaerobic digestion operating parameters after their addition. The various AD additives were examined in a sufficient cycle of operation for three biogas plants located in northern Greece. In this manner, the effectiveness was investigated in multiple initial feeds and unstable operating situations caused by the seasonality of specific feedstocks. The existing operation state in the three biogas plants was recorded before and after adding the supplements. The addition of zeolite contributed to the reduction in the total ammoniacal nitrogen values in BG01 and BG03 plants. 8.4 tn of zeolite were added to the BG01 and BG03 plants over a period of two months. Low levels of trace element concentrations were observed in the BG02 plant; this issue was addressed by adding 5 kg of a trace element mixture every week over a period of 60 days. Introducing additives proved to be a stabilization factor in AD performance and an inhibition mediator

Improvement of MBBR-MBR Performance by the Addition of Commercial and 3D-Printed Biocarriers

Moving bed biofilm reactor combined with membrane bioreactor (MBBR-MBR) constitute a highly effective wastewater treatment technology. The aim of this research work was to study the effect of commercial K1 biocarriers (MBBR-MBR K1 unit) and 3D-printed biocarriers fabricated from 13X and Halloysite (MBBR-MBR 13X-H unit), on the efficiency and the fouling rate of an MBBR-MBR unit during wastewater treatment. Various physicochemical parameters and trans-membrane pressure were measured. It was observed that in the MBBR-MBR K1 unit, membrane filtration improved reaching total membrane fouling at 43d, while in the MBBR-MBR 13X-H and in the control MBBR-MBR total fouling took place at about 32d. This is attributed to the large production of soluble microbial products (SMP) in the MBBR-MBR 13X-H, which resulted from a large amount of biofilm created in the 13X-H biocarriers. An optimal biodegradation of the organic load was concluded, and nitrification and denitrification processes were improved at the MBBR-MBR K1 and MBBR-MBR 13X-H units. The dry mass produced on the 13X-H biocarriers ranged at 4980–5711 mg, three orders of magnitude larger than that produced on the K1, which ranged at 2.9–4.6 mg. Finally, it was observed that mostly extracellular polymeric substances were produced in the biofilm of K1 biocarriers while in 13X-H mostly SMP