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Strategies for the Startup of Methanogenic Inverse Fluidized‐Bed Reactors Using Colonized Particles
Author(s) -
AlvaradoLassman A.,
SandovalRamos A.,
FloresAltamirano M.G.,
VallejoCantú N.A.,
MéndezContreras J.M.
Publication year - 2010
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143009x12487095237233
Subject(s) - fluidized bed , continuous reactor , bioreactor , batch processing , sequencing batch reactor , biomass (ecology) , batch reactor , process engineering , methane , substrate (aquarium) , environmental science , wastewater , waste management , pulp and paper industry , chemical engineering , chemistry , computer science , environmental engineering , engineering , catalysis , biology , ecology , agronomy , biochemistry , organic chemistry , programming language
One of the inconveniences in the startup of methanogenic inverse fluidized‐bed reactors (IFBRs) is the long period required for biofilm formation and stabilization of the system. Previous researchers have preferred to start up in batch mode to shorten stabilization times. Much less work has been done with continuous‐mode startup for the IFBR configuration of reactors. In this study, we prepared two IFBRs with similar characteristics to compare startup times for batch‐ and continuous‐operation modes. The reactors were inoculated with a small quantity of colonized particles and run for a period of 3 months, to establish the optimal startup strategy using synthetic media as a substrate (glucose as a source of carbon). After the startup stage, the continuous‐ and batch‐mode reactors removed more than 80% of the chemical oxygen demand (COD) in 51 and 60 days of operation, respectively; however, at the end of the experiments, the continuous‐mode reactor had more biomass attached to the support media than the batch‐mode reactor. Both reactors developed fully covered support media, but only the continuous‐mode reactor had methane yields close to the theoretical value that is typical of stable reactors.
Then, a combined startup strategy was proposed, with industrial wastewater as the substrate, using a sequence of batch cycles followed by continuous operation, which allows stable operation at an organic loading rate of 20 g COD/L·d in 15 days. Using a fraction of colonized support as an inoculum presents advantages, with respect to previously reported strategies.