Biological nutrient removal (BNR) in wastewater treatment to remove
carbonaceous substrates, nutrients and phosphorus, has recently become
increasingly popular worldwide due to increasingly stringent regulations.
Biological fluidized bed (BFB) technology, which could be potentially
used for BNR processes, can provide some advantages such as high
efficiency and compact structure. This present invention incorporates the
fixed-film biological fluidized bed technology with the biological
nutrient removal in a twin liquid-solid fluidized bed, which has achieved
the simultaneous elimination of organic carbon, nitrogen and phosphorus,
in a very efficient manner and with very compact space requirements. The
BNR-LSFB has two fluidized beds, running as anoxic/anaerobic and aerobic
processes to accomplish simultaneous nitrification and denitrification
and to remove carbonaceous substrates, nutrients and phosphorus, with
continuous liquid and solids recirculation through the anoxic/anaerobic
bed and the aerobic bed. The new BNR-LSFB system is not only an excellent
alternative for conventional activated sludge type BNR technologies but
is also capable of processing much higher loadings and suitable for
industrial applications.