Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
Chemosphere
Vol. 140
, 2015, Pages: 54–62

Comparison of single-stage and two-phase anaerobic sludge digestion systems Performance and microbial community dynamics

Yogananda Maspolim, Yan Zhou, Chenghong Guo, Keke Xiao, Wun Jern Ng

Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.

Abstract

This study compared reactor performance and the respective microbial community dynamics in the conventional single-stage and 2-phase anaerobic digestion (AD) systems, treating municipal sludge to generate methane. The 2-phase system’s COD and VS reduction, and methane production could be maintained throughout the three HRTs tested (p = 0.05), which was associated with an increase in organic loading (30 d = 1.5 g COD L-1 d-1, 20 d = 2.2 g COD L-1 d-1 and 10 d = 3.5 g COD L-1 d-1); but this was not so in the single-stage system where it deteriorated at HRT of 10 d (p = 0.05) due to impairment of particulate COD reduction. qPCR, DGGE and the subsequent phylogenetic analysis revealed that microbial adaptation occurred as the seed sludge formed a different community in each reactor at 30 d HRT; however, no further significant microbial shift occurred at lower HRTs. The presence of specific hydrolytic and acidogenic Flavobacteriales and Clostriales in the acidogenic reactor may have allowed for enhanced hydrolysis and acidogenesis, leading to higher organic loading tolerance at 10 d HRT. Methanogenic activity in the acidogenic reactor may have been performed by Methanobacteriales and Methanosarcinaceae. Operation of the acidogenic reactor at neutral pH may have to be considered to ensure the cultivation of propionate oxidising bacteria, which could in turn, prevent reactor “souring” during high load conditions.

Keywords: Two-phase anaerobic digestion; Municipal sludge; Biogas; Microbial community; DGGE; qPCR.

 
 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution