Technical Publications

A Fixed-Film Biotrickling Filter for Treatment of Odorous Air

Lawrence C.C. Koe
College of Engineering, Environmental & Water Resources Division, School of Civil and Environmental Engineering, Nanyang Technological University

Lin Wu, Yong Ying Loo, Yih Ming Koh, Jurn Wei Chai, Yan Wu

Abstract

Odour emissions are ranked as the first air quality concern of the public. The collection and handling of sewage have usually been a source of odour problems. Chemical scrubbers have been traditionally used to treat these odour emissions. Despite their high effectiveness, the operational and maintenance costs are expensive due to the use of chemicals. As a result, various biological processes have emerged as potentially less costly and more environmentally conscious alternatives for odour control. Among them, fixed-film biotrickling filters have additional advantages in terms of effective use of space and high treatment efficiency. Because of these advantages, a bench-scale fixed-film biotrickling filter was set up in laboratory to investigate the start-up process and the effects of various operating parameters on the performance of the biotrickling filter through a series of experimental runs. The reactor was then shifted to a local wastewater treatment plant to test its treatment efficiency under actual field conditions. Bacterial viability in different research phases was also studied. It was observed that the practical gas retention time required for a desirable H2S removal of 99% could be as low as 5 seconds from the laboratory runs. The practical elimination rate was found to be 40 g-H2S/m3-hr for H2S removal efficiency greater than 99%. The bacterial density was observed to decrease when the reactor was shifted to the site. Odour removal was satisfactory as 75% to 80% of the odour was removed by the biotrickling filter.