Turning organic wastes into hydrogen (H2) by using anaerobic fennentative technology is an ideal concept because this can accomplish both waste treatment and energy recovery objectives. However, H2 production using anaerobic fennentative approaches faces a fundamental limitation of poor H2 production yield (i.e. < 4 mol H2 per mol of hexose). This article gives an overview on the limitations of...

Studies have identified two distinct biological processes capable of biotransforming polychlorinated biphenyls (PCBs): aerobic oxidative processes and anaerobic reductive processes. It is now known that these two complementary activities are occurring naturally in the environment. Anaerobic PCB dechlorination, responsible for the conversion of highly chlorinated PCBs to lightly chlorinated orth...

The H2CO3-HCO3system in vertebrates did not evolve directly from the original forms of life. Organic evolution probably dates back some 109 years.1 Although there may have been small amounts of CO2 present in the atmosphere and CO2 was definitely present in the earth mantle, it is generally accepted that metabolic pathways were anaerobic in nature. This conclusion is based on several lines of e...

Anaerobic digestion (AD) of biowastes is one of the most common ways to produce methane-rich biogas, which has considerable potential to replace the fossil fuel used in multiple applications, such as vehicular transportation, internal combustion engines, cogeneration of heat and power systems and many other systems. Many companies are involved in the design and construction of anaerobic digesti...

−− The present work is focused on evaluating the anaerobic digestion of complex substrates (proteins and carbohydrates) in anaerobic fluidized bed reactors (AFBRs). In a previous paper, an AFBR model was adjusted using only the experimental data obtained during the acclimatization stage (glucose and acetate-based feeding) of two mesophilic bioreactors. Here, the sensitivity of that model to rep...

Members of the genus Arthrobacter are usually regarded as obligate aerobic bacteria. The anaerobic growth and energy metabolism of two Arthrobacter species were investigated. Arthrobacter globiformis utilized both nitrate ammonification and lactate, acetate and ethanol producing fermentation processes for anaerobic growth. Only nitrate supported anaerobic growth of Arthrobacter nicotianae. Anae...

Huge amounts of waste biosolids are produced from biological processes as waste water treatment, agriculture and food production. The volatile compounds could be utilised as a source for renewable energy in anaerobic processes. However, the anaerobic degradation is slow so that large fermenters are necessary. By ultrasonic disintegration the rate limiting hydrolysis of volatile solids is substi...

The coupling between a microalgal pond and an anaerobic digester is a promising alternative for sustainable energy production by transforming carbon dioxide into methane using solar energy. In this paper, we demonstrate the ability of the original ADM1 model and a modified version (based on Contois kinetics for the hydrolysis steps) to represent microalgae anaerobic digestion. Simulations were ...

The awareness of the effect of abiotic processes in wastewater treatment and sludge treatment technologies is increasing considerably. However traditionally used mathematical models either do not represent abiotic processes, or use simplified approaches. This paper presents a mathematical model able to represent abiotic processes in the steady-state model developed for the anaerobic reactor in ...

Recharge events that deliver electron acceptors such as O2, NO3, SO4, and Fe3+ to anaerobic, contaminated aquifers are likely important for natural attenuation processes. However, the specific influence of recharge on (bio)geochemical processes in ground water systems is not well understood. The impact of a moderate-sized recharge event on ground water chemistry was evaluated at a shallow, sand...