Long-term performance of peat biofilters treating ethyl acetate, toluene, and its mixture in air

✍ Scribed by F. Javier Alvarez-Hornos; Carmen Gabaldón; Vicente Martínez-Soria; Paula Marzal; Josep-Manuel Penya-roja; Marta Izquierdo

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 312 KB
• Volume: 96
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.21096

✦ Synopsis

Abstract

Three laboratory‐scale peat biofilters were operated at 90 s empty bed residence time (EBRT) for over a year. Biodegradation of ethyl acetate, toluene, or a 1:1 mixture were investigated. In first stage, inlet concentration was progressively increased from 0.4 to 4.5 g/m^3^. The maximum elimination capacity (EC) found for ethyl acetate was 190 gC/m^3^·h, and it was not affected by toluene. The maximum EC found for toluene as a sole contaminant was 150 gC/m^3^·h, but the presence of ethyl acetate decreased the toluene maximum EC to 80 gC/m^3^·h. From respirometry monitoring, values of 3.19 g CO~2~/gC and 3.06 g CO~2~/gC for pure ethyl acetate and pure toluene, respectively, were found, with overall yield coefficients of 0.13 g dry biomass produced per gram ethyl acetate consumed and 0.28 g dry biomass produced per gram toluene consumed. CO~2~ production in the 1:1 mixture was successfully simulated. Dynamics of living and dead cells were monitored in four sections of the biofilters. Concentrations ranged between 2.6 × 10^9^ and 3.0 × 10^10^ cells per gram‐dry peat for total bacteria, and 2.4 × 10^9^–1.9 × 10^10^ cells per gram‐dry peat for living bacteria. At high loads loss of bacterial density in the inlet zones, and increase in the dead cells percentages up to 60% was observed. In second stage, long‐term performance at an inlet concentration of 1.5 g/m^3^ was evaluated to show the process feasibility. Good agreement with previous data was obtained in terms of EC and CO~2~ production. Restoration of living cells proportion was also observed. Biotechnol. Bioeng. 2007;96:651–660. © 2006 Wiley Periodicals, Inc.