The role of organic matter and extracellular polymeric substances of various municipal sludges on their rheology and dewaterability.

This study investigates the influence of organic matter and extracellular polymeric substances (EPS) on the rheological properties and dewaterability of diverse sludge types. Eight waste activated sludge and eleven anaerobically digested sludge samples were collected from eleven full-scale wastewater treatment plants across Australia. Rheological measurements were performed at native and at uniform total solids concentration (TS) of 4.

Formate-driven photoautotrophic growth and biopolymer storage in anaerobic purple bacteria.

Using formate as a CO proxy offers key advantages for autotrophic polyhydroxyalkanoate (PHA) production by lowering substrate costs and avoiding the limitations of gas-fed CO systems. This study aimed to enrich photoautotrophic PHA-accumulating purple phototrophic bacteria (PPB) using formate, with an acetate-fed culture as a photoheterotrophic control. Light promoted growth in the formate-fed reactor, reaching soluble chemical oxygen demand (COD) consumption rates and biomass content of 14 ± 2 mgCOD Lh and 1100 ± 500 mgVSS L at 50 W m.

Effect of light intensity and wavelength on carotenoid profiles in mixed cultures of purple phototrophic bacteria.

Purple phototrophic bacteria (PPB) have strong potential for applications such as protein-rich animal feed, with carotenoids providing added immune-nutritional value. This study investigated carotenoid profiles in PPB mixed cultures under varying light conditions, focusing on individual carotenoid quantification using advanced analytical techniques, rather than relying on total carotenoid estimates or spectral inference alone. Lycopene, 3,4-dihydrorhodopin, and rhodopin were consistently identified as the major carotenoids across conditions.

Microbial population shifts during disturbance induced foaming in anaerobic digestion of primary and activated sludge.

Foaming during anaerobic digestion (AD) of sewage sludge is poorly understood and remains an uncontrollable operational obstacle for sewage treatment systems globally, causing mechanical damage, increased hazards and reduced biogas recovery. Foams during AD commonly occur after process disturbances, such as organic loading shocks. However, it is still unclear whether these foam events are biologically driven and linked to the abundance of organisms like filamentous or hydrophobic bacteria.

Recent advances and challenges in mechanistic modelling of photosynthetic processes for wastewater treatment.

Phototrophy-based wastewater treatment has the potential to reduce wastewater bioremediation costs, improving environmental impacts and allowing for enhanced resource recovery. Microbial interactions occurring in phototrophic-chemotrophic consortia treating wastewater are particularly complex, and with varying impact on each microbial clade by different chemical, biological and physical factors, including light-related aspects. For this reason, mechanistic mathematical modelling of these systems is challenging, and the resulting models are especially complex.