Principles and potential of thermal hydrolysis of sewage sludge to enhance anaerobic digestion

Gahlot P., Balasundaram G., Tyagi V. K., ATABANI A., Suthar S., Kazmi A., ...More

Environmental Research, vol.214, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 214
  • Publication Date: 2022
  • Doi Number: 10.1016/j.envres.2022.113856
  • Journal Name: Environmental Research
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Applied Science & Technology Source, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), Artic & Antarctic Regions, BIOSIS, CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, Computer & Applied Sciences, EMBASE, Environment Index, Geobase, Greenfile, MEDLINE, Metadex, Pollution Abstracts, Public Affairs Index, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Anaerobic digestion, Biogas, Methane, Resource recovery, Sewage sludge, Thermal pretreatment, Wastewater
  • Erciyes University Affiliated: Yes


© 2022 Elsevier Inc.Sewage sludge is rich source of carbon, nutrients, and trace elements and can be subjected to proper treatment before disposal to fulfill government legislation and protect receiving environments. Anaerobic digestion (AD) is a well-adopted technology for stabilizing sewage sludge and recovering energy-rich biogas and nutrient-rich digestate. However, a slow hydrolysis rate limits the biodegradability of sludge. In the present study we have attempted to explain the potential of thermal hydrolysis to enhance anaerobic digestion of sewage sludge. Thermal pretreatment improves biodegradability and recycling of the sludge as an excellent energy and nutrients recovery source at reasonable capital (CAPEX) and operational (OPEX) costs. Other pretreatments like conventional (below/above 100 °C), temperature-phased anaerobic digestion (TPAD), microwave and chemically mediated thermal pretreatment have also been accounted. This review provides a holistic overview of sludge's characterization and value-added properties, various techniques used for sludge pretreatment for resource recovery, emphasizing conventional and advanced thermal pretreatment, challenges in scale-up of these technologies, and successful commercialization of thermal pretreatment techniques.