Abstract
Anaerobic digestion is a widely used technology for sewage sludge stabilization and biogas production. Although the structure and composition of the microbial communities responsible for the process in full-scale anaerobic digesters have been investigated, little is known about the microbial successional dynamics during the start-up phase and the response to variations occurring in such systems under real operating conditions. In this study, bacterial and archaeal population dynamics of a full-scale mesophilic digester treating activated sludge were investigated for the first time from the start-up, performed without adding external inoculum, to steady-state operation. High-throughput 16S rRNA gene sequencing was used to describe the microbiome evolution. The large majority of the reads were affiliated to fermentative bacteria. Bacteroidetes increased over time, reaching 22% of the total sequences. Furthermore, Methanosaeta represented the most abundant methanogenic component. The specific quantitative data generated by real-time PCR indicated an enrichment of bacteria and methanogens once the steady state was reached. The analysis allowed evaluation of the microbial components more susceptible to the shift from aerobic to anaerobic conditions and estimation of the microbial components growing or declining in the system. Additionally, activated sludge was investigated to evaluate the microbial core selected by the WWTP operative conditions.
Highlights
IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
After the establishment of steady-state conditions, the analysis revealed that both microbial components were almost constant throughout the plant operation
A successful start-up phase, carried out without adding external anaerobic inoculum, of a full-scale mesophilic digester treating activated sludge was investigated in this work for the first time
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Anaerobic digestion (AD) is a well-known technology that uses mixed microbial communities for the treatment of a wide range of organic waste streams and subsequent conversion to biogas [1]. Due to its potential impacts on the environment and human health, sewage sludge requires proper treatment and management. AD can be efficiently applied for the valorization of waste-activated sludge (WAS) due to its cost-effectiveness and resource recovery capacities [2]. The treatment and disposal of the excess sludge produced by wastewater treatment plants (WWTPs) is a serious environmental problem and represent up to 50% of the operating costs of the plant [3]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
