Serpentine submerged attached growth reactor

A waste water treatment system, comprising:

• an equalization tank adapted to receive wastewater and provide primary settling of solids from said waste water, resulting in equalized wastewater, said equalization tank comprised of a bottom, a top, and a side wall interconnecting the bottom and top, said bottom, top and side wall defining a hollow, equalization tank interior, said equalization tank having an influent inlet for receiving wastewater thereby providing a path for the wastewater from a source external to the equalization tank and into the equalization tank interior, said equalization tank also having an outlet, which is in communication with a bioreactor inlet and adapted to provide equalized wastewater to the bioreactor;
• a submerged attached growth bioreactor connected to and adapted to receive the equalized wastewater output from said equalization tank and providing oxidation of carbonaceous matter, nitrification and denitrification of said equalization tank equalized wastewater output, said bioreactor comprised of a bottom, a top and a side wall interconnecting the bottom and top, said bioreactor bottom, top and side wall defining a hollow, bioreactor interior, said bioreactor having said bioreactor inlet in communication with said equalization tank outlet, said bioreactor interior having a biofilter comprised of three filter cells filled with filter media having a high specific surface area, and comprising a first cell, a second cell and a third cell, said filter cells being separated by vertical walls, said first filter cell having a top in communication with said equalization tank outlet and adapted to receive said equalized wastewater, a closed bottom, and an opening in the wall between the first and second filter cells adjacent the first filter cell bottom and a second filter cell bottom, said second filter cell having a top and a closed bottom, and an opening in the wall between the second filter cell and the third filter cell adjacent the second filter cell top and a third filter cell top above the second filter cell filter media, said third filter cell having an open bottom terminating in an underdrain positioned beneath said filter cells and above a plenum adjacent the bioreactor bottom, wherein said plenum is an open space below the underdrain, said bioreactor interior having an open head space above said filter cells adjacent the bioreactor top;
• a clear well connected to and adapted to receive a treated wastewater output from said bioreactor storing a portion of the treated wastewater output to provide return flows and periodic backwashes, wherein a remainder of the treated wastewater output is discharged from the clear well interior;
• wherein the clear well is comprised of a bottom, a top, and a side wall interconnecting the bottom and top, said bottom, top and side wall defining a hollow, clear well interior, said clear well having a clear well inlet with an external inlet pipe connected to a bioreactor outlet in fluid communication with the bioreactor plenum;
• an outlet backwash pipe inserted through the bioreactor side wall into the head space interconnected to the equalization tank;
• a plurality of air lines brought through the bioreactor side wall into the head space and down through each individual filter cell's filter media and terminating adjacent each filter cell bottom, each said air line providing process air and backwash air from an external source to each filter cell;
• a plurality of pumps within said clear well interior, said plurality of pumps having a first pump on the clear well bottom, said first pump connected to said clear well inlet and adapted to provide reverse flow from the clear well interior back through the bioreactor interior, said plurality of pumps having a second pump on the clear well bottom, said second pump interconnected to a clear well discharge outlet, said second pump adapted to discharge the contents of said clear well interior out through said clear well discharge outlet;
• wherein the equalization tank outlet is positioned vertically lower than the equalization tank inlet;
• wherein the clear well inlet is positioned vertically lower than the equalization tank outlet;
• wherein equalization tank wastewater with a substantial amount of solids removed is passed through to the bioreactor open head space, through the first filter cell top flowing downward through the first filter cell filter media to said opening in the wall between the first and second filter cells adjacent the first filter cell bottom and second filter cell bottom, into the second filter cell flowing upward through the second filter cell filter media to said opening in the wall between the second filter cell and third filter cell adjacent the second filter cell and third filter cell tops above the second filter cell filter media, then entering into the third filter cell, flowing downward through the third filter cell filter media to the third filter cell bottom, into the plenum and exiting the bioreactor as treated effluent through the bioreactor outlet into the clear well inlet pipe, into the clear well inlet pipe, into the clear well first inlet into the clear well interior.