摘要 |
<p>A compact water treatment plant has at least one vertical stack of dissolved air flotation (DAF) type clarifiers. Raw water is directed first to a single stage clarifier with a shallow tank. Its output is fed to an underlying two stage clarifier, preferably one with tall, mutually isolated cells, inclined baffles over a filtration medium in each cell, a cell-by-cell backwash capability, and an arrangement for isolating the first filtrate from the clarified water. Preferably, there are two such stacks in side-by-side array to provide a peak-load capacity, redundancy, and extreme compactness. Also preferably, clarified water from the single stage clarifier flows to the two stage clarifier via a bioreactor and an associated DAF clarifier. A source of aeration defines an upper, aerobic zone in the reactor where bacteria act on organic contaminants (COD's and BOD's). Strips of a deep pile, woven textile form a biocarrier. The strips oscillate in the tank. A portion of the bioliquor and sludge from the bioreactor-dedicated clarifier recirculate through a lower, anoxic zone of the bioreactor for denitrification.</p> |