Abstract

Two identical facultative ponds were operated in parallel under the same environmental conditions with the same sewage supply. While one pond was operated as control at fixed depth and constant sewage inflow, the hydraulic conditions for the other pond were varied. It was observed that the BOD and COD removals in the control pond varied almost linearly with areal loading at all times. On the other hand, BOD and COD removals exhibited distinctly different patterns in the variable pond.