The Influence of Loading Rate and Variable Temperatures on Microbial Communities in Anaerobic Digesters

Energies

Richard J. Ciotola³  Jay F. Martin³  Abigail Tamkin³  Juan M. Castańo²  James Rosenblum¹  Michael S. Bisesi¹ 

[1] Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Cunz Hall, 1841 Neil Avenue, Columbus, OH 43210, USA; E-Mails:;Facultad de Ciencias Ambientales, Universidad Tecnológica de Pereira (Faculty of Environmental Sciences, Technological University of Pereira), Apartado Aéreo 097, Pereira 660017, Colombia; E-Mail:;Department of Food, Agricultural and Biological Engineering, The Ohio State University, Agricultural Engineering Building, 590 Woody Hayes Dr., Columbus, OH 43210, USA; E-Mails:

关键词: anaerobic digestion;    archaeal communities;    temperature;    organic loading rate;    terminal restriction fragment length polymorphisms (T-RFLP);   

DOI  :  10.3390/en7020785

来源: mdpi

【 摘 要 】

The relationship between seasonal temperatures, organic loading rate (OLR) and the structure of archaeal communities in anaerobic digesters was investigated. Previous studies have often assessed archaeal community structure at fixed temperatures and constant OLRs, or at variable temperatures not characteristic of temperate climates. The goal of this study was to determine the maximum OLR that would maintain a balanced microbial ecosystem during operation in a variable temperature range expected in a temperate climate (27–10 °C). Four-liter laboratory digesters were operated in a semi-continuous mode using dairy cow manure as the feedstock. At OLRs of 1.8 and 0.8 kg VS/m³·day the digesters soured (pH < 6.5) as a result of a decrease in temperature. The structure of the archaeal community in the sour digesters became increasingly similar to the manure feedstock with gains in the relative abundance of hydrogenotrophic methanogens. At an OLR of 0.3 kg VS/m³·day the digesters did not sour, but the archaeal community was primarily hydrogenotrophic methanogens. Recommendations for operating an ambient temperature digester year round in a temperate climate are to reduce the OLR to at least 0.3 kg VS/m³·day in colder temperatures to prevent a shift to the microbial community associated with the sour digesters.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland