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

Impact of food waste addition in energy efficient municipal wastewater treatment by aerobic granular sludge process

Recently, one of the main purposes of wastewater treatment plants is to achieve a neutral or positive energy balance while meeting the discharge criteria. Aerobic granular sludge (AGS) technology is a promising technology that has low energy and footprint requirements as well as high treatment performance. The effect of co-treatment of municipal wastewater and food waste (FW) on the treatment performance, granule morphology, and settling behavior of the granules was investigated in the study. A biochemical methane potential (BMP) test was also performed to assess the methane potential of mono- and co-digestion of the excess sludge from the AGS process. The addition of FW into wastewater enhanced the nutrient treatment efficiency in the AGS process. BMP of the excess sludge from the AGS process fed with the mixture of wastewater and FW (195 ± 17 mL CH4/g VS) was slightly higher than BMP of excess sludge from the AGS process fed with solely wastewater (173 ± 16 mL CH4/g VS). The highest methane yield was observed for co-digestion of excess sludge from the AGS process and FW, which was 312 ± 8 mL CH4/g VS. Integration of FW as a co-substrate in the AGS process would potentially enhance energy recovery and the quality of effluent in municipal wastewater treatment.

A review of enhanced municipal wastewater treatment through energy savings and carbon recovery to reduce discharge and CO2 footprint

Municipal wastewater treatment that mainly performed by conventional activated sludge (CAS) process faces the challenge of intensive aeration-associated energy consumption for oxidation of organics and ammonium, contributing to significant directly/indirectly greenhouse gas (GHG) emissions from energy use, which hinders the achievement of carbon neutral, the top priority mission in the coming decades to cope with the global climate change. Therefore, this article aimed to offer a comprehensive analysis of recently developed biological treatment processes with the focus on reducing discharge and CO2 footprint. The biotechnologies including "Zero Carbon", "Low Carbon", "Carbon Capture and Utilization" are discussed, it suggested that, by integrating these processes with energy-saving and carbon recovery, the challenges faced in current wastewater treatment plants can be overcome, and a carbon-neutral even be possible. Future research should investigate the integration of these methods and improve anammox contribution as well as minimize organics lost under different scales.

Attack Graph Utilization for Wastewater Treatment Plant

In general, automation involves less human intervention, which leads to dependence on preprogrammed machines and processes that operate continually and carry out numerous tasks. This leads to predictable repeating behavior that can be used to advantage. Due to the incorporation of the Internet of Things into such automated processes, these cyber–physical systems are now vulnerable to cyberattacks, the patterns of which can be difficult to identify and understand. Wastewater treatment plants (WTPs) can be challenging to run, but the treatment process is essential since drinking water and water that can be recycled are extremely important to obtain. The increasing susceptibility of WTPs to cyberattacks brought on by exploitation of their weaknesses poses a further challenge. Understanding system weaknesses and potential exploits is necessary for securing such cyber–physical systems. An attack graph utilization and visualization approach for WTPs is presented in this paper. A formal modeling and encoding of the system were carried out using a structural framework (AADL). The system model was then continuously checked by a model-checker called JKind against security requirements to create attack routes, which were then merged into an attack graph using a tool called GraphViz.