Many larger wastewater treatment plants use Anaerobic Digestion, a bacterial process that is carried out in the absence of oxygen. Compared to the conventional activated sludge process, Anaerobic Digestion is more energy efficient, reduces dewatered biosolids by 7-12 times (as compared to conventional processes) and produces useful methane gas (biogas). Gardner Denver Nash liquid ring pumps and...

Using dark fermentation, hydrogen can be generated from renewable organics including waste materials. Key to successful application of anaerobic fermentation is to uncouple liquid and biomass retention times in reactor system. This paper reviews reactor configurations (fixed-bed, fluidized-bed, upflow anaerobic sludge blanket and continuous stirred tank reactors) and operating processes (batch,...

Genomic markers for anaerobic microbial processes in marine sediments-sulfate reduction, methanogenesis, and anaerobic methane oxidation-reveal the structure of sulfate-reducing, methanogenic, and methane-oxidizing microbial communities (including uncultured members); they allow inferences about the evolution of these ancient microbial pathways; and they open genomic windows into extreme microb...

An easy-to-implement controller based on gas phase measurements for anaerobic digestion processes was developed. The controller is based on the indirect control of COD in the effluent by means of controlling the hydrogen concentration in the biogas. The fast response of hydrogen under destabilizations, such as those caused by overloads, guarantees an early actuation on the system before it dest...

Operators of wastewater treatment plants first of all are responsible for the required good quality of the effluent before it is discharged to the environment. Today attention is being shifted more and more to optimize the operation of treatment plants not only to reduce energy consumption or other costs in an economic sense but with regard to ecological aspects like reduction of greenhouse gas...

Nitrite-dependent anaerobic oxidation of methane (n-damo) and ammonium (anammox) are two recently discovered processes in the nitrogen cycle that are catalyzed by n-damo bacteria, including "Candidatus Methylomirabilis oxyfera," and anammox bacteria, respectively. The feasibility of coculturing anammox and n-damo bacteria is important for implementation in wastewater treatment systems that cont...

up flow anaerobic sludge blanket (uasb) reactors have been increasingly used for industrial wastewater treatment. because of existing problems in startup step of these reactors, in this research the startup of a uasb in pilot scale and room temperature condition was studied. the total height of uasb reactor was 270 cm and effective height was 240 cm. diameter of the reactor in lower part was 20...

Some of the key factors affecting the adaptation of anaerobic digestion processes to increasing levels of salinity were determined in batch tests using brown seaweed as a feedstock. It was found that cultures seeded with non-saline anaerobic inoculum required an adaptation period of up to two months to reach the same level of methane production rate as in those cultures seeded with saline-adapt...

The fermentation process in which organic material is degraded and biogas (composed of mainly methane and carbon dioxide) is produced, is referred to as anaerobic digestion. Anaerobic digestion processes occur in many places where organic material is available and redox potential is low (zero oxygen). This is typically the case in stomachs of ruminants, in marshes, sediments of lakes and ditche...

Pseudomembranouscolitis is one of the serious infectious diseases with a high mortality. It tends to occur in association with antibiotic therapy, especially with broad spectrum antibacterial agents. The major causative pathogen is the anaerobic bacterium Clostridium difficileP This bacterium is extremely sensitive to oxygen, and requires strict anaerobic conditions for growth. Once exposed to ...