Effect of non-feeding period length on the intermittent operation of UASD reactors treating dairy effluents

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Coelho, NM (Author) Other; Alírio Rodrigues (Author) FEUP; Arroja, LM (Author) Other; Capela, IF (Author) Other

Journal

Title: Biotechnology and Bioengineering

Vol. 96

Pages: 244-249

ISSN: 0006-3592

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 9 Citations

Other information

Authenticus ID: P-004-BXB

DOI: 10.1002/bit.21095

Abstract (EN): Recent environmental concerns have prompted a re-evaluation of conventional management strategies and refueled the search of innovative waste management practices. In this sense, the anaerobic digestion of both fat and the remaining complex organic matter present in dairy wastewaters is attractive, although the continuous operation of high rate anaerobic processes treating this type of wastewaters causes the failure of the process. This work accesses the influence of non-feeding period length on the intermittent operation of mesophilic UASB reactors treating dairy wastewater, in order to allow the biological degradation to catch up with adsorption phenomenon. During the experiments, two UASB reactors were subject to three organic loading rates, ranging from 6 to 12 g(COD.)L(-1.)d(-1), with the same daily load applied to both reactors, each one with a different non-feeding period. Both reactors showed good COD removal efficiencies (87-92%). A material balance for COD in the reactors during the feeding and nonfeeding periods showed the importance of the feedless period, which allowed the biomass to degrade substrate that was accumulated during the feeding period. The reactor with the longest non-feeding period had a better performance, which resulted in a higher methane production and adsorption capacity for the same organic load applied with a consequent less accumulation of substrate into the biomass. In addition, both reactors had a stable operation for the organic load of 12 g(COD)(.)L(-1.)d(-1), which is higher than the maximum applicable load reported in literature for continuous systems (3-6 g(COD)(.)L(-1.)d(-1)).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6