Search results for "ANAEROBIC DIGESTION"

Complete Genome Sequence of a New Ruminococcaceae Bacterium Isolated from Anaerobic Biomass Hydrolysis

2018

ABSTRACT A new Ruminococcaceae bacterium, strain HV4-5-B5C, participating in the anaerobic digestion of grass, was isolated from a mesophilic two-stage laboratory-scale leach bed biogas system. The draft annotated genome sequence presented in this study and 16S rRNA gene sequence analysis indicated the affiliation of HV4-5-B5C with the family Ruminococcaceae outside recently described genera.

Ultrasound assisted method to increase soluble chemical oxygen demand (SCOD) of sewage sludge for digestion

2004

The aim of this study was to clarify the possibilities to increase the amount of soluble chemical oxygen demand (SCOD) and methane production of sludge using ultrasound technologies with and without oxidising agents. The study was done using multivariate data analyses. The most important factors affected were discovered. Ultrasonically assisted disintegration increased clearly the amount of SCOD of sludge. Also more methane was produced from treated sludge in anaerobic batch assays compared to the sludge with no ultrasonic treatment. Multivariate data analysis showed that ultrasonic power, dry solid content of sludge (DS), sludge temperature and ultrasonic treatment time have the most signi…

Disintegration of Wastewater Activated Sludge (WAS) for Improved Biogas Production

2018

Due to rapid urbanization, the number of wastewater treatment plants (WWTP) has increased, and so has the associated waste generated by them. Sustainable management of this waste can lead to the creation of energy-rich biogas via fermentation processes. This review presents recent advances in the anaerobic digestion processes that have led to greater biogas production. Disintegration techniques for enhancing the fermentation of waste activated sludge can be apportioned into biological, physical and chemical means, which are included in this review; they were mainly compared and contrasted in terms of the ensuing biogas yield. It was found that ultrasonic- and microwave-assisted disintegrati…

Commercial Biogas Plants: Lessons for Ukraine

2020

Ukraine has enough biomass resources for biogas production. However, this energy potential is not used sufficiently. This research is aimed at examining the current experience of commercial biogas systems in the Europe Union and its adaptation for Ukraine. Special attention was paid to economic indicators, such as specific investment costs, production costs (biogas, biomethane, and electricity), and incentives. Using statistical data for the European Union and Ukraine, the biogas potential for Ukraine (based on European experience) was determined. The economic competitiveness of biogas production was evaluated compared to alternatives, such as photovoltaic, wind power, biomass, conventional…

Environmental assessment of the Sibiu County, Romania: proposal for sewage sludge and OFMSW management

2017

The aim of the work is to assess current solid waste management (SWM) and wastewater treatment (WWT) in the county of Sibiu, Romania. Sibiu is a region where industrialization and tourism are spreading constantly, while pollution monitoring and the introduction of circular economy (CE) principles are still lacking. The environmental issues are mostly due to the absence of reliable sanitation systems, in particular for what concerns sewage sludge treatment. Moreover, Organic fraction from selective collection of municipal solid waste is still missing, since it is disposed of directly to landfill, increasing environmental pollution and contributing considerably to global warming. As a result,…

Effects of biochar addition on anaerobic digestion and comparison of different biochar qualities

2017

Tässä pro gradu -työssä tutkittiin, voidaanko anaerobisen mädätyksen toimintaa parantaa lisäämällä mädätysprosessiin pieniä määriä biohiiltä. Anaerobista mädätystä tutkittiin laboratoriomittakaavan biokaasukokeilla, joissa biokaasureaktoreita käsiteltiin sekä pyrolyyttisesti että hydrodermaalisesti tuotetulla biohiilellä. Biohiilen mahdolliseen kykyyn lievittää ammoniakki-inhibitiota kiinnitettiin huomiota. Seitsemän pyrolyyttisen ja yhden hydrodermaalisen hiilen ominaisuuksia vertailtiin, jotta voitaisiin määrittää soveltuvia biohiiliä anaerobiseen mädätykseen. Biohiilistä analysoitiin ammonium-adsorptiokapasiteetti, irtoavan liukoisen orgaanisen kokonaishiilen (DOC) ja liukoisen kokonaist…

Alkaline pretreatment to enhance one-stage CH4 and two-stage H2/CH4 production from sunflower stalks: Mass, energy and economical balances

2015

Abstract Biological production of second generation biofuels such as biohydrogen (H2) or methane (CH4) represents a promising alternative to fossils fuels. Alkaline pretreatments of lignocellulosic biomass are known to enhance the accessibility and the bioconversion of hollocelluloses during anaerobic digestion and dark fermentation processes. In the present study, four different configurations were investigated: one-stage CH4 continuous and two-stage H2 batch/CH4 continuous process with and without alkaline pretreatment of sunflower stalks (55 °C, 24 h, 4 g NaOH/100 g TS). The results showed that two stage H2/CH4 (150 ± 3.5 mL CH4 g−1 VS) did not improve methane yields compared to one stag…

Development and pilot-scale validation of a fuzzy-logic control system for optimization of methane production in fixed-bed reactors

2018

International audience; The objective of this study was to develop an advanced control system for optimizing the performance of fixed-bed anaerobic reactors. The controller aimed at maximizing the bio-methane production whilst controlling the volatile fatty acids content in the effluent. For this purpose, a fuzzy-logic controller was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale (350 L) treating raw winery wastewater. The results showed that the controller was able to adequately optimize the process performance, maximizing the methane production in terms of methane flow rate, resulting in an average methane yield of about 0.29 LCH4 g−1 COD. On the other han…

Biogas production from meat and pulp and paper industry by-products

2014

Chemically Stressed Bacterial Communities in Anaerobic Digesters Exhibit Resilience and Ecological Flexibility

2020

Anaerobic digestion is a technology known for its potential in terms of methane production. During the digestion process, multiple metabolites of high value are synthesized. However, recent works have demonstrated the high robustness and resilience of the involved microbiomes; these attributes make it difficult to manipulate them in such a way that a specific metabolite is predominantly produced. Therefore, an exact understanding of the manipulability of anaerobic microbiomes may open up a treasure box for bio-based industries. In the present work, the effect of nalidixic acid, γ-aminobutyric acid (GABA), and sodium phosphate on the microbiome of digested sewage sludge from a water treatmen…