This work studied the influence of effluent recirculation upon the kinetics of anaerobic degradation of dairy wastewater in the feedless phase of intermittent upflow anaerobic sludge bed (UASB) reactors. Several laboratory-scale tests were performed with different organic loads in closed circuit UASB reactors inoculated with adapted flocculent sludge. The data obtained were used for determinati...

agricultural residues have high potential to produce biogas, but they contain lignocellulosicmaterials which are not easily degradable, so the pretreatment is required. chemical pretreatmentincreases the rate of degradation and efficiency of biogas production. this study has beeninvestigated the effect of 4% -urea, 5%-ammonia and 8%-sodium hydroxide on degradation of ricestraw and production of...

The ability of certain bacterial species to oxidize nicotinic acid was first reported by Allison (1) who used suspensions of bacteria isolated by Dubos and Miller (2). Koser and Baird (3) later isolated strains of Pseudomonas jluorescens which grew on a synthetic medium in which nicotinic acid was the sole carbon source. These strains did not attack isonicotinic acid, picolinic acid, or pyridin...

The attenuation of methane and four chlorofluorocarbons was investigated in a dynamic methane and oxygen counter-gradient system simulating a landfill soil cover. Soil was sampled at Skellingsted Landfill, Denmark. The soil columns showed a high capacity of methane oxidation with oxidation rates of 210 g m(-2) d(-1) corresponding to a removal efficiency of 81%. CFC-11 and to a lesser extent als...

Volatile fatty acids are the most important intermediates in anaerobic digestion, and their degradations are extremely complicated thermodynamically. In this research, syntrophic anaerobic digestion of volatile fatty acids using enriched acetogenic and methanogenic cultures in a batch reactor at mesophilic conditions was investigated. Interactive effects of key microbiological and operating var...

Estrogens are important environmental contaminants that disrupt endocrine systems and feminize male fish. We investigated the potential for anaerobic biodegradation of the estrogens 17-alpha-ethynylestradiol (EE2) and 17-beta-estradiol (E2) in order to understand their fate in aquatic and terrestrial environments. Cultures were established using lake water and sediment under methanogenic, sulfa...

Anaerobic fungi (phylum Neocallimastigomycota) are common inhabitants of the digestive tract of mammalian herbivores, and in the rumen, can account for up to 20% of the microbial biomass. Anaerobic fungi play a primary role in the degradation of lignocellulosic plant material. They also have a syntrophic interaction with methanogenic archaea, which increases their fiber degradation activity. To...

As the most prevalent preservative worldwide for many years, pentachlorophenol (PCP) has attracted much interest in the study of biodegradation in soil and aquatic ecosystems. However, the key microorganisms involved in anaerobic degradation are less well understood. Hence, we used DNA-based stable isotope probing (SIP) to identify the PCP-degrading microorganisms in iron-rich paddy soil under ...

RDX is a persistent and highly mobile groundwater contaminant that represents a major remediation challenge at numerous munitions manufacturing and load-assemblage-package facilities. This work presents proof of concept that permeable reactive iron barriers might be a viable approach to intercept and degrade RDX plumes. Specifically, RDX was rapidly reduced in aquifier microcosms amended with F...

Electrode respiring bacteria (ERB) possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS) because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential toward organic contaminants. Here we report once such bacterial strain...