Design and performance of a fibrous bed bioreactor for odor treatment

Biological processes have become popular for odor treatment. In this study, a novel fibrous bed bioreactor was applied for treatment of odorous gas. T he column reactor was packed with spirally wound fibrous sheet material on which a consortium of microorganisms selected from activated sludge was imm obilized. The first stage of this work comprised a preliminary study that a imed at investigating the feasibility of the fibrous bed bioreactor for tre atment of odorous volatile fatty acids (VFAs). In this stage, the performan ce of a fibrous bed bioreactor at increasing mass loadings ranging from 9.7 to 104.2 g/(m(3).h) was studied. VFA removal efficiencies above 90%; were achieved at mass loadings up to 50.3 g/(m(3).h). At a mass loading of 104.2 g/(m(3).h), removal efficiency was found to be 87.7%. In the second stage of the work, the process was sealed up with design and operational consider ations, namely, packing medium, process condition, and configuration select ions. A trickling biofilter with synthetic fibrous packing medium was selec ted. It was operated under countercurrent flow of gas and liquid streams. T he effects of inlet concentration and empty bed retention time on bioreacto r performance were studied. The bioreactor was effective in treating odorou s VFAs at mass loadings up to 32 g/(m(3).h), at which VFAs started to accum ulate in the recirculation liquid, indicating that the biofilm was unable t o degrade all the VFAs introduced. Although VFAs accumulated in the liquid phase, the removal efficiency remained above 99%, implying that the biochem ical reaction rate, rather than gas-to-liquid mass transfer rate, was the l imiting factor of this process. The bioreactor was stable for longterm oper ation; no clogging and degeneration of the packing medium was observed duri ng the 4-mo operation.