Chapter 24 - Cambi Thermal Hydrolysis Process (CambiTHP) for sewage sludge treatment

Abstract

Sustainability and circular economy have become two keywords in the field of wastewater treatment. Sustainable technologies that convert “waste to wealth” and promote “resource recovery” are driving today’s wastewater industry. Sludge generated from wastewater treatment plants is considered waste that requires disposal at a cost. The United States Environmental Protection Agency (EPA) published a regulation, known as the EPA Biosolids Rule, for the treatment and disposal of sewage sludge. According to the rule, sewage sludge treated to Class A levels can be used beneficially as a fertilizer or soil amendment. Advanced anaerobic digestion (AAD) with the thermal hydrolysis process (THP) is the leading technology for producing Class A biosolids, with the Norwegian company Cambi (CambiTHP) as the most prevalent supplier for THP systems. The THP ensures the sustainable and safe disposal of sludge free of pathogens and promoting a circular economy. In some sewage treatment plants (STP) with CambiTHP, the biosolids produced can be sold as a fertilizer or soil amendment to farmers and other buyers, generating revenue for the plants. In addition, CambiTHP increases the production of energy from the downstream anaerobic digestion (AD) process, reduces the required digester volume, and decreases the volume of biosolids to be handled or transported while improving its quality. Overall, STPs using CambiTHP have a significantly lower operational cost of sludge treatment and disposal than the conventional sludge treatment process without CambiTHP.