by fluctuating hydraulic or organic load, but that it
was sensitive to pH variations, due to alkalinity consumption
due to nitrification. Willers et al. (1993)
reported that slurries of animal manures (< 2% dry
solids) had been treated from 1976 until 1991 in
SBR systems in The Netherlands to achieve BODs,
TKN, NHa-N and PO4 removals of better than 95%,
the last by the addition of lime. Incomplete denitrification
was encountered during cold winters,
when the BOD/N ratio of the aerated manure was
too low. The popularity of the SBR is due to its
single-tank design and the ease of its automation.
A number of issues need clarification for ASBNR
treatment of slaughterhouse and rendering
wastewater: