Abstract: A system and method for forming a filter media support system with multiple locking mechanisms. The support system comprises two or more interlocking rows of support blocks. One or more slides and one or more guides protrude from the side walls of the blocks. Each guide is conformed to receive one slide from a neighboring block, forming a first locking joint. The side walls also comprise one or more nubs and one or more recesses. Each nub is conformed to fit within one recess of a neighboring block, forming a second locking joint. In one embodiment, the method for assembling the support system comprises aligning a slide of a first support block with a guide of a second support block. The slide of the first support block is vertically moved into the guide of the second support block. Force is applied so that the nubs are flexed within the recesses.

Abstract: A system and method for forming a filter media support system with dual locking mechanisms. The support system comprises two or more interlocking rows of support blocks. One or more slides and one or more guides protrude from the side walls of the blocks. Each guide is conformed to receive one slide from a neighboring block, forming a first locking joint. The side walls also comprise one or more posts and one or more sockets. Each post is conformed to fit within one socket of a neighboring block, forming a second locking joint. In one embodiment, the method for assembling the support system comprises aligning a slide of a first support block with a guide of a second support block. The slide of the first support block is vertically moved into the guide of the second support block. Force is applied so that the posts snap-lock into the sockets.

Abstract: A system (10) comprising multiple units (40a-40h) and method for filtration of wastewater (20) is disclosed. Simultaneous denitrification of a single filter unit and normal filtration of the remaining filter units is provided for. Separate flow control systems (36) are described.

Abstract: An underdrain block for a filter system comprises a housing that has of a top wall, a bottom wall, a first end wall, a second end wall, a first side wall, and a second side wall. The end walls and the side walls connect the top wall to the bottom wall. The bottom wall forms two lateral rows of support legs configured to straddle infrastructure of the filter system. One or more snap-locking mechanisms are located on the side walls so that adjacent underdrain blocks are interconnected by the locking mechanisms when snapped in place. In one embodiment, the first side wall comprises one or more tongue lugs and the second side wall comprises one or more groove lugs, each groove lug defines a groove for mating with the tongue lug so that adjacent housings are interconnected by the tongue-in-groove locking mechanisms when the tongue lugs are snapped into the grooves.

Abstract: A lid for an underdrain block that has a top surface defining an opening for receiving fill material. The top surface forms a ridge circumscribing the opening, the lid comprising a top, a bottom and a peripheral edge, the peripheral edge comprising a rim adapted to interlock with the ridge. The ridge of the underdrain block can have a flange perpendicular to the top surface and the rim on the lid is adapted to tightly fit over the flange so that the rim interlocks with the flange. Alternatively, the underdrain block for a filter system comprises a hollow plastic housing comprising a top wall that defines an opening for receiving the fill material. The top wall forms a ridge surrounding the opening and the lid seals the opening in the top wall. The lid comprises a peripheral edge that forms a u-shaped rim. The u-shaped rim has a locking means to tightly fit over the ridge so that the rim interlocks with the ridge so as to seal the opening.

Abstract: A lid for an underdrain block that has a top surface defining an opening for receiving fill material. The top surface forms a ridge circumscribing the opening, the lid comprising a top, a bottom and a peripheral edge, the peripheral edge comprising a rim adapted to interlock with the ridge. The ridge of the underdrain block can have a flange perpendicular to the top surface and the rim on the lid is adapted to tightly fit over the flange so that the rim interlocks with the flange. Alternatively, the underdrain block for a filter system comprises a hollow plastic housing comprising a top wall that defines an opening for receiving the fill material. The top wall forms a ridge surrounding the opening and the lid seals the opening in the top wall. The lid comprises a peripheral edge that forms a u-shaped rim. The u-shaped rim has a locking means to tightly fit over the ridge so that the rim interlocks with the ridge so as to seal the opening.

Abstract: A process for removing BOD and suspended solids from wastewater without passing through a primary clarifier or secondary aeration tank, the process. During the process, raw sewage wastewater, comprising soluble BOD, insoluble BOD and suspended solids, is piped directly to a deep bed granular filter. The bed depths of deep bed filter are within a range of approximately 2.0 ft to approximately 10.0 ft. The raw sewage wastewater is filtered by filtration through the deep bed filter in which the filter media is a granular media with a size range between approximately 2.0 mm to 10.0 mm. Backwashing the deep bed filter occurs at least once every 48 hours.

Abstract: This invention relates to a method and apparatus of denitrification. The apparatus includes a weir block, a denitrification vessel having a wall surface, and filter media having microorganisms on their surfaces. The weir block may have a convex outer surface which is tangentially adjacent to and preferably contiguous with the upper end of the wall, whose lower end is in contact with the water in the denitrification vessel. The method may include passing the wastewater over the convex surface of the weir block, passing the water over the second surface of the substantially vertical wall and into the denitrification vessel while preferably maintaining substantially laminar flow and limiting the dissolved oxygen in the denitrification vessel, preferably to below about 5 mg/L and more preferably to below about 4 mg/L.