Patent ID: 7081203

Claim:
A wastewater treatment module for treating contaminated wastewater in a biologically active treatment bed, said apparatus comprising: (a) a substantially watertight basin, said basin having an outer bottom surface adapted for placement on a substrate, an inner bottom surface, and upwardly extending sidewalls, and a peripheral rim having a selected elevation above said bottom, said basin having a selected containment volume V; (b) a plurality of units of at least one mass transfer packing media located within said basin, said mass transfer packing media sized and shaped to comprise a surface area adapted to support the growth of biological organisms thereon, and a void area within and between said packing media, and resulting when a plurality of mass transfer packing media are packed together in a substantial void space within said basin, said mass transfer packing media extending upward from said inner bottom surface for a height H 1 ; (c) a standpipe, and a distributor pipe, said distributor pipe in fluid communication with said standpipe, said standpipe mounted to downwardly direct wastewater to be treated toward said distributor pipe, said distributor pipe mounted in said basin, said distributor pipe comprising a plurality of discharge outlets adapted to discharge wastewater therefrom so that said wastewater reaches said mass transfer packing media; (d) mounted above and substantially covering said mass transfer packing media, at least one screen layer, said at least one screen layer comprising a screen sized and shaped to substantially prevent a granular media of preselected size from downwardly penetrating said at least one screen layer to reach said at least one mass transfer packing, so as to protect said at least one mass transfer packing media against receipt of granular media thereon; (e) above said at least one screen layer and within said basin, a first granular media of a first preselected size, said first granular media extending upward from said at least one screen layer for a height H 2 ; (f) above said first granular media, a number N of upper granular media layers each of a preselected size, wherein N is a positive integer, and wherein said upper granular media layers extend (1) for a height H 3 between said first granular media layer and the elevation of said peripheral rim, (2) upward beyond said peripheral rim to a top surface portion for a height H 4 , and (3) laterally outward from said basin and downward toward said substrate to a peripheral edge.