Evaluation of parameters for monitoring an anaerobic co-digestion process |
| |
Authors: | L Björnsson M Murto B Mattiasson |
| |
Institution: | (1) Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, 22100 Lund, Sweden e-mail: lovisa.bjornsson@biotek.lu.se Tel.: +46-46-2228324 Fax: +46-46-2224713, SE |
| |
Abstract: | The system investigated in this study is an anaerobic digester at a municipal wastewater treatment plant operating on sludge
from the wastewater treatment, co-digested with carbohydrate-rich food-processing waste. The digester is run below maximum
capacity to prevent overload. Process monitoring at present is not extensive, even for the measurement of on-line gas production
rate and off-line pH. Much could be gained if a better program for monitoring and control was developed, so that the full
capacity of the system could be utilised without the risk of overload. The only limit presently set for correct process operation
is that the pH should be above 6.8. In the present investigation, the pH was compared with alkalinity, gas production rate,
gas composition and the concentration of volatile fatty acids (VFA). Changes in organic load were monitored in the full-scale
anaerobic digester and in laboratory-scale models of the plant. Gas-phase parameters showed a slow response to changes in
load. The VFA concentrations were superior for indicating overload of the microbial system, but alkalinity and pH also proved
to be good monitoring parameters. The possibility of using pH as a process indicator is, however, strongly dependent on the
buffering capacity. In this study, a minor change in the amount of carbohydrates in the substrate had drastic effects on the
buffering effect of the system.
Received: 21 January 2000 / Received revision: 10 July 2000 / Accepted: 16 July 2000 |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|