Coupling high-rate activated sludge process with aerobic granular sludge process for sustainable municipal wastewater treatment

Achieving a neutral/positive energy balance without compromising discharge standards is one of the main goals of wastewater treatment plants (WWTPs) in terms of sustainability. Aerobic granular sludge (AGS) technology promises high treatment performance with low energy and footprint requirement. In this study, high-rate activated sludge (HRAS...

Impact of primary treatment methods on sludge characteristics and digestibility, and wastewater treatment plant-wide economics

Biogas production from anaerobic sludge digestion plays a central role for wastewater treatment plants to become more energy-efficient or even energy-neutral. Dedicated configurations have been developed to maximize the diversion of soluble and suspended organic matter to sludge streams for energy production through anaerobic digestion, such...

Impact of primary sedimentation on granulation and treatment performance of municipal wastewater by aerobic granular sludge process

Aerobic granules contain microorganisms that are responsible for carbon, nitrogen, and phosphorus removal in aerobic granular sludge (AGS) process in which aerobic/anoxic/anaerobic layers (from surface to core) occur in a single granule. Optimizing the aerobic granular sludge (AGS) process for granulation and efficient nutrient removal can be...

Primary and A-sludge treatment by anaerobic membrane bioreactors in view of energy-positive wastewater treatment plants

Energy-rich sludge can be obtained from primary clarifiers preceding biological reactors. Alternatively, the incoming wastewater can be sent to a very-high-loaded activated sludge system, i.e., a so-called A-stage. However, the effects of applying an A-stage instead of a primary clarifier, on the subsequent sludge digestion for long-term...

Anaerobic membrane bioreactors for sludge digestion: Current status and future perspectives

Excess sewage sludge in wastewater treatment plants (WWTPs) is regarded the key energy source for achieving energy neutral WWTPs. The anaerobic digestion process transforms sludge-organic matter into methane, which subsequently can be used for heat and electricity production. Conventional anaerobic digesters (ADs) have been used for sludge...