Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions.

Globally, many populations suffer from a lack of access to basic sanitation facilities. This is partly caused by a combination of water resource shortages and the high cost of conventional centralised treatment systems. A novel decentralised treatment technology based on sub-critical hydrothermal processing of organic wastes at toilet-scale, contributes to addressing these economic and resource limitations.

An improved model for the kinetics of non-oxidative hydrothermal process.

Hydrothermal processing as a post-treatment technology for sludge has attracted great interest globally as it could reduce the amount of sludge considerably. This experimental study developed a comprehensive kinetic model of cellulose degradation via non-oxidative hydrothermal processing at various temperatures (ranges 180-260 °C). Values of activation energies and pre-exponential factors were determined using chemical oxygen demand (COD)-based lumped concentrations.

Rheological Behavior of High Cell Density LS46 Cultures during Production of Medium Chain Length Polyhydroxyalkanoate (PHA) Polymers.

The rheology of high-cell density (HCD) cultures is an important parameter for its impact on mixing and sparging, process scale-up, and downstream unit operations in bioprocess development. In this work, time-dependent rheological properties of HCD LS46 cultures were monitored for microbial polyhydroxyalkanoate (PHA) production. As the cell density of the fed-batch cultivation increased (0 to 25 g·L cell dry mass, CDM), the apparent viscosity increased nearly nine-fold throughout the fed-batch process.

Development of High Cell Density Cultivation Strategies for Improved Medium Chain Length Polyhydroxyalkanoate Productivity Using LS46.

High cell density (HCD) fed-batch cultures are widely perceived as a requisite for high-productivity polyhydroxyalkanoate (PHA) cultivation processes. In this work, a reactive pulse feed strategy (based on real-time CO or dissolved oxygen (DO) measurements as feedback variables) was used to control an oxygen-limited fed-batch process for improved productivity of medium chain length (mcl-) PHAs synthesized by LS46. Despite the onset of oxygen limitation half-way through the process (14 h post inoculation), 28.

Hydrogen Oxidation Influences Glycogen Accumulation in a Verrucomicrobial Methanotroph.

Metabolic flexibility in aerobic methane oxidizing bacteria (methanotrophs) enhances cell growth and survival in instances where resources are variable or limiting. Examples include the production of intracellular compounds (such as glycogen or polyhydroxyalkanoates) in response to unbalanced growth conditions and the use of some energy substrates, besides methane, when available. Indeed, recent studies show that verrucomicrobial methanotrophs can grow mixotrophically through oxidation of hydrogen and methane gases respiratory membrane-bound group 1d [NiFe] hydrogenases and methane monooxygenases, respectively.