Christophe Renner1, Jean-Pierre Levasseur1, Philippe G. Micone2 & Thierry Pagé2
1Veolia Water, 2Odotech
The composting unit built on the Ginestous site (Toulouse, France) treats 11,000 T/year of 30% dehydrated solid-matter sludge. The production of compost proper is relatively conventional: after mixing with a structuring co-product, the waste-water treatment-plant sludge is stored in piles where it is aired through forced ventilation and mechanical turnover. The process air from the fermenting piles and the air extracted from the building are deodorized: - The ammonia-rich process air is treated by acid scrubbing, then heterotrophic biofiltration; - The building air is sent directly through the same biofiltration. The heterotrophic biofilter, consisting of a 1.3 m thick peat and coconut fibre bed, treats a volume of 60,000 m3/h. The process gas, the building and the biofilter output gases are measured continuously by a network of OdoWatch™ electronic noses. The network measures the odors continuously at 5-second intervals (dilution to threshold or odor concentration). It is thus possible to know the level of odor reduction associated with the biofilter, instantaneously or historically. The monitoring system includes a weather station so as to map the odor plume of the composting unit and biofilter in real time. This article presents the composting process, its biofiltration system as well as the continuous odor monitoring system implemented. The electronic-nose training and calibration protocol is presented, as well as the biofilter odor-abatement performance results for highly fluctuating operating conditions owing to the batch composting operating mode. KEY WORDS Electronic nose, olfactometry, odor, biofiltration
Aqua Enviro Ltd
T: 0113 8730728
c/o Tidal Accounting, HQ Offices, Radley House, Richardshaw Road, Leeds, West Yorkshire, LS28 6LE