Dear Colleagues,

The effective disposal of waste-activated sludge (WAS) has been extremely significant and urgent for the highly efficient operation of wastewater treatment plants considering the increasing amounts of WAS being generated. Meanwhile, scarcity of resources and energy drive the public to seek for more efficient and sustainable treatment approaches for WAS disposal and resource recovery. Anaerobic fermentation has been widely accepted as an effective and eco-friendly strategy for WAS disposal. Indeed, high-value products and energy could be recovered via this process. However, the WAS fermentation performance is restricted by various parameters, such as pH, temperature, sludge retention time, the efficiency of solubilization and hydrolysis, etc. How to effectively improve WAS fermentation efficiency through the development of novel and advanced methods is of vital importance. In parallel, the WAS fermentation is mainly a biological process; hence, the functional microorganisms as well as their metabolic functions and activities play vital roles in the transformation and valorization of WAS. It is also necessary to efficiently regulate and maintain the high metabolic activity and functions of microorganisms involved in WAS fermentation. Also, the disclosure of underlying mechanisms via advanced techniques and methods at the levels of microbial community, metabolic pathways, genetic expression levels were also urgent to uncover. The relevant studies will provide new sights into sludge fermentation and guidance for sludge disposal.

We are inviting research papers and reviews about novel insights on sludge fermentation. The aim of this Special Issue is to provide an insight into the latest findings of sludge fermentation, including the biologically volatile fatty acids, hydrogen and polyhydroxyalkanoates (PHA) production from WAS, and novel and advanced methods for enhancing WAS fermentation efficiency. Moreover, the illustration of the specific microbial functions in microbial consortia, elucidation of the biological principles and main controlling factors that regulate the metabolic bioprocesses, and provision of biotechnological solutions and regulation strategies are also encouraged. If you have any questions, please contact the editor to discuss the topic relevance.

Dr. Yang Wu
Guest Editor

Manuscript Submission Information

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• waste-activated sludge
• anaerobic fermentation
• solubilization
• hydrolysis
• acidification
• pretreatment
• microorganisms
• metabolic functions
• volatile fatty acids
• hydrogens
• PHA