Bioreactor system for multi-stage biological wastewater treatment

A multiple stage bioreactor system for microbiological treatment of wastewater, the bioreactor system comprising:

• at least one highly-flexible substrate for providing a superficial environment conducive for culturation of microbes, said substrate including:
• (a) a large plurality of threads, said threads disposed in a generally longitudinal direction, and
• (b) at least two cross-support elements disposed across and associated with said plurality of threads, so as to provide support for and loosely associate said threads,
• wherein a length extension of said threads in said substrate is in a range of 80% to 98%.

A multiple stage bioreactor system for microbiological treatment of wastewater, the bioreactor system comprising:

• at least one bioreactor including:
• (a) a feed inlet for receiving a stream of at least partially-untreated wastewater;
• (b) a plurality of substrate bundles, each bundle of said substrate bundles including a plurality of laminar, highly-flexible substrates for supporting biomass growth, each of said substrates having threads including a plurality of synthetic filaments, said substrates being juxtaposed in a substantially parallel manner with respect to each other, within said bioreactor,
• (c) an air supply manifold for fluidly connecting to an air source, said manifold including a plurality of diffusing elements, for forced rising and diffusion of air, said diffusing elements positioned with respect to said substrate bundles such that said air rises and diffuses through said laminar substrates,
• and wherein said diffusing elements are further positioned with respect to said plurality of substrates such that said rising of air creates a controlled hydrodynamic circulation within said bioreactor, and
• wherein said controlled hydrodynamic circulation is characterized by a linear velocity range bounded by an upper level that enables biomass to settle on said laminar substrates, and bounded by a lower level that provides a pre-determined minimum level of available oxygen throughout said substrates.