276032 Economical Study of Bioparticles Used for Denitrification in Fluidized Bed Bioreactors (FBBR)

Thursday, November 1, 2012: 9:30 AM
Conference B (Omni )
Ahmed Khiray Eldyasti, Civil and Environmental Engineering Department, University of Western Ontario, London, ON, Canada, George Nakhla, Chemical and Biochemical Engineering, University of Western Ontario, London, ON, Canada and Jingxu Zhu, Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, ON, Canada

Economical study of different bioparticles for four Denitrifying Fluidized Bed Bioreactors (DFBBRs) using granulated maxi-blast plastic, granulated multi-blast plastic, natural zeolite, and lava rock were investigated to evaluate the feasibility of employing these media as carrier media or “bioparticles” for denitrification in a fluidized bed bioreactors. The work showed that the multi-blast plastic and natural zeolite achieved nitrogen and organic removal efficiencies of 99% and 87%, respectively whereas, the maxi-blast plastic and lava rock achieved removals efficiencies of 94% and 77%, respectively. Low biomass yields were observed for multi-blast plastic and natural zeolite of 0.12g VSS/g COD, while the yield for both the maxi-blast plastic and lava rock was 0.19 g VSS/g COD. Comprehensive economic evaluation of the fluidization energy consumption of each media considering the initial capital cost, operating and running cost, and replacement cost showed that the multi-blast plastic and maxi-blast plastic media were cheaper than natural zeolite and lava rock. Considering the average sphericity of each media, the particles with average sphericity of 0.9 i.e. multi-blast plastic and natural zeolite achieved nitrogen and organic removal efficiencies of 99% and 87%, respectively with a fluffy protruding biofilm whereas the particles with average sphericity of 0.5 i.e. maxi-blast plastic and lava rock achieved removals efficiencies of 94% and 77%, respectively with a patchy biofilm. Low biomass yields were observed for multi-blast plastic and natural zeolite with a sphericity of 0.9 of 0.12g VSS/g COD, while the yield for both the maxi-blast plastic and lava rock with sphericities of 0.5 and 0.6 respectively was 0.19 g VSS/g COD. Annualized unit media costs are mostly governed by fluidization energy costs which constitute 76%-97% of the total costs i.e. capital and media replacement costs are insignificant over the long-term. Considering denitrification performance and annualized overall media costs including fluidization energy, media loss, and capital cost, Multi-Blast (MB) plastic particle is the most suitable and economic media for the denitrification process in DFBBR, with a 20 years annualized capital and running cost of $1.56-$1.72 per kg, 30% cheaper than natural zeolite and 50% cheaper than lava rock.

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