Denitrification Performance of Pseudomonas denitrificans in a Fluidized‐Bed Biofilm Reactor and in a Stirred Tank Reactor

Abstract

Denitrification of a synthetic wastewater containing nitrates and methanol as carbon source was carried out in two systems – a fluidized‐bed biofilm reactor (FBBR) and a stirred tank reactor (STR) – using Pseudomonas denitrificans over a period of five months. Nitrogen loading was varied during operation of both reactors to assess differences in the response to transient conditions. Experimental data were analyzed to obtain a comparison of denitrification kinetics in biofilm and suspended growth reactors. The comparison showed that the volumetric degradation capacity in the FBBR (5.36 kg N · m –3 · d –1 ) was higher than in the STR, due to higher biomass concentration (10 kg BM · m –3 vs 1.2 kg BM m –3 ). Denitrification of a synthetic wastewater containing nitrates and methanol as a carbon source was experimentally investigated using Pseudomonas denitrificans growing in a fluidized‐bed biofilm reactor (FBBR) and in a stirred tank reactor (STR). The denitrification performance of the two systems was compared in terms of volumetric capacity and biomass capacity.