Anaerobic Digestion for Pathogen Reduction in Waste Treatment and Safe Agricultural Use of Digestates

Abstract

Anaerobic Digestion (AD) is a widely used process for treating organic wastes and producing renewable energy. This review examines the effectiveness of AD in reducing pathogens in various waste streams and evaluates the safety of using digestates as agricultural fertilizers. The mechanisms of pathogen inactivation during AD are explored, including the roles of temperature, pH, ammonia, and microbial competition. Case studies demonstrate pathogen reduction rates ranging from 1-5 log units for different microorganisms. While AD can significantly reduce pathogen loads, challenges remain in achieving consistent and complete sanitization. Factors affecting digestate safety, such as feedstock composition, operating conditions, and post-treatment, are discussed. The review also addresses methodologies for enhancing pathogen reduction in AD systems.