Activated Sludge Process and Energy

  • J. Rajesh BanuEmail author
  • U. Ushani
  • R. Yukesh Kannah


Sludge is the chief by-product of wastewater treatment plants, and further clearance of sludge is a major and complex environmental issue. Stabilization of sludge is done to diminish the pathogen content, eradicate unpleasant odors, and diminish the potential for decomposition. The cost to treat surplus amounts of waste activated sludge is very high, accounting for up to 60% of the entire operational costs of a treatment plant. Sludge degradation is carried out by many treatment methods, which are followed by energy production. Sludge degradation involves many pretreatment approaches: biological, chemical, thermal, mechanical, etc. Every pretreatment ends with anaerobic/aerobic digestion, which leads to biogas production. Among these methods, anaerobic digestion is very effective due to its eco-friendly impact and high potential for energy recovery. The rate-limiting step of anaerobic/aerobic digestion is hydrolysis of higher organic compounds to smaller molecules. These pretreatment methods play a key role in enhancing hydrolysis which, in return, increases biogas production with varying energy and cost consumption. Many research studies are ongoing to figure out the best pretreatment methods with high biogas production and low energy and cost consumption. To cut down energy and cost utilization, many pretreatments are combined together, such as thermochemical and chemobiological pretreatments, etc.


Energy Hydrolysis Pretreatment Sludge Stabilization 


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© Springer Nature Singapore Pte Ltd. 2017

Authors and Affiliations

  1. 1.Department of Civil EngineeringRegional Centre of Anna UniversityTirunelveliIndia

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