Influence of increasing anode surface area on nitrite-absent ammonium oxidation in a continuous single-chamber bio-electrochemical system.

Reducing energy consumption in conventional nitrogen removal processes is a crucial and urgent requirement. This study proposes an efficient electrode-dependent bio-electrochemical anaerobic ammonium (NH-N) oxidation (BE-ANAMMOX) process, employing a carbon brush as the electron acceptor and voltage of 0.8 V.

Nanoparticle-associated single step hydrogen fermentation for the conversion of starch potato waste biomass by thermophilic Parageobacillus thermoglucosidasius.

In the present study, starch-based potato peel waste biomass (PWB) was utilized as a potential substrate for hydrogen production via dark fermentation by the thermophillic amylase producing strain Parageobacillus thermoglucosidasius KCTC 33548. Supplementation of FeO nanoparticles (300 mg/L) led to a 4.15-fold increase in hydrogen production as compared to the control.

Metagenomics approach and canonical correspondence analysis of novel nitrifiers and ammonia-oxidizing archaea in full scale anaerobic-anoxic-oxic (A2/O) and oxidation ditch processes.

Various microorganisms are involved in nitrogen removal, and their group compositions depend closely on operating parameters. The structures and functions of nitrification microorganisms in full-scale anaerobic-anoxic-oxic (A2/O) and oxidation ditch processes were analyzed using metagenomics and canonical correspondence analysis. The community structure of ammonia-oxidizing archaea in the oxidation ditch was 3.

Towards the practical application of bioelectrochemical anaerobic digestion (BEAD): Insights into electrode materials, reactor configurations, and process designs.

Anaerobic digestion (AD) is one of the most widely adopted bioenergy recovery technologies globally. Despite the wide adoption, AD has been challenged by the unstable performances caused by imbalanced substrate and/or electron availability among different reaction steps. Bioelectrochemical anaerobic digestion (BEAD) is a promising concept that has demonstrated potential for balancing the electron transfer rates and enhancing the methane yield in AD during shocks.

Effect of a side-stream voltage supplied by sludge recirculation to an anaerobic digestion reactor.

This study showed that side stream voltage supplied by sludge recirculation from an auxiliary bio-electrochemical anaerobic digestion (ABEAD) reactor appears to have a similar effect as main stream voltage supply to an anaerobic digestion (AD) reactor. The increased sludge recirculation rate enhanced the operation stability at a high OLR. H-producing bacterial community was improved in bio-electrochemical anaerobic digestion (BEAD) and ABEAD reactors and was increased with increase in sludge recirculation rate.

Contribution analysis of methane production from food waste in bulk solution and on bio-electrode in a bio-electrochemical anaerobic digestion reactor.

Quantitative evaluation of methane production either in bulk sludge or biofilm on electrodes was performed in a bio-electrochemical anaerobic digestion (BEAD) reactor with a lower electrode surface area/reactor working volume (A/V) ratio (7.0 m/m). Methane production by electrochemical reaction was also evaluated in the BEAD reactor with a biofilm-free electrode under the same conditions as in other experimental sets.

Effects of a novel auxiliary bio-electrochemical reactor on methane production from highly concentrated food waste in an anaerobic digestion reactor.

In this study, the effects of indirect voltage supply to an anaerobic digestion (AD) reactor on methane production and the removal of chemical oxygen demand (COD) were studied at different organic loading rates (OLRs) of food waste by the circulation from an auxiliary bio-electrochemical reactor (ABER) with stainless steel (STS304) electrodes. The effects of the indirect voltage on microbial communities in the AD reactor were also investigated. In a bio-electrochemical anaerobic digestion (BEAD) reactor with direct voltage, it was possible to achieve stable COD removal and methane production even at a higher OLR of 10.

Bioconversion of lignin and its derivatives into polyhydroxyalkanoates: Challenges and opportunities.

Renewable energy resources are considered to be promising for the development of a sustainable circular economy. Among various alternatives, the microbial route for various biofuels production is quite lucrative. Use of cellulose and lignocellulose for methane, H , organic acids, ethanol, and cellulase has been explored a lot in the past few decades.

Long-term evaluation of methane production in a bio-electrochemical anaerobic digestion reactor according to the organic loading rate.

In this study, the effects of differing organic loading rates (OLRs) on methane production were evaluated via long-term operation of a bio-electrochemical anaerobic digestion (BEAD) reactor and an anaerobic digestion (AD) reactor. In the AD reactor, the maximum OLR was 4 kg/m·d whereas the electro-active microbial community in bulk and on the biofilm of the BEAD reactor produced methane even at 10 kg/m·d. The BEAD reactor rapidly removed volatile fatty acids (VFAs) and reduced H to H at high OLRs, thereby preventing VFA accumulation and pH decrease.

Control of accumulated volatile fatty acids by recycling nitrified effluent.

Background: Volatile fatty acids (VFA) often accumulate in anaerobic digestion systems, decreasing pH levels and causing unstable operational performance and poor biogas production. The aim of this study is to improve anaerobic digestion efficiency by controlling/reducing the accumulation of VFAs in a continuous anaerobic digestion system.

Methods: NO -N was added to the digester and its effects on VFAs were investigated.

Co-production of polyhydroxyalkanoates and carotenoids through bioconversion of glycerol by Paracoccus sp. strain LL1.

Polyhydroxyalkanoates (PHA) have emerged as a potential alternative to synthetic plastics, although its large-scale production is limited by the expenditure incurred in feed materials. Co-production of various valuable bioproducts along with PHA has been proposed to alleviate the overall production cost. Here, high-yield co-production of PHA and carotenoids was achieved in single step fermentation by Paracoccus sp.

Microbial communities change in an anaerobic digestion after application of microbial electrolysis cells.

Microbial electrolysis cells (MECs) are being studied to improve the efficiency of anaerobic digesters and biogas production. In the present study, we investigated the effects of electrochemical reactions in AD-MEC (anaerobic digester combined with MECs) on changes in the microbial communities of bulk sludge through 454-pyrosequencing analysis, as well as the effect of these changes on anaerobic digestion. Methanobacterium beijingense and Methanobacterium petrolearium were the dominant archaeal species in AD, while Methanosarcina thermophila and Methanobacterium formicicum were dominant in AD-MEC at steady-state.