Submerged biological wastewater treatment system

Abstract

This invention relates to a process and reactor system suitable for biological treatment of wastewaters or for other applications wherein effective and intimate contact between biological populations attached to a fixed surface and liquid born chemicals and gaseous atmospheres is required. The reactor includes a sealed housing generally having a plurality of independent-vertical chambers, each open at the top and bottom and each filled with high surface-area packing and disposed annularly around a central-vertical chamber. The central vertical chamber is also open at the top and bottom, but free of packing. The bottom of the central chamber is in communication with the bottom of each of the independent-annular columns by means of a bottom-freeboard chamber. The top of the central-vertical chamber is also in communication with the top of each independent-vertical chamber by means of a top-freeboard chamber created by setting the liquid level in the reactor at a position above the top of all vertical chambers. Agitation within the reactor maintained by effecting downward flow of fluid and gases in said central-vertical chamber. A central-vertical chamber contains a pump which circulates fluid from the top freeboard chamber and/or the fluid and gases from the gaseous freeboard of the reactor, downward through the central-chamber, radially across the floor of the reactor and vertically up through the vertical chambers. The fluid then flows radially inward in the top-freeboard chamber and returns to the central chamber thus providing a continuous toroidal recirculation.