Bioreactor for biological treatment of contaminated water

DETAILED DESCRIPTION We claim: 1.
A bioreactor unit for the aerobic biological treatment of hydrocarbon contaminated waste water and off-gases, said bioreactor comprising a biotreatment chamber which comprises: a vertically extending housing unit forming walls, floor and ceiling of said biotreatment chamber, said housing unit comprising a door for accessing said treatment chamber; waste water inlet means for discharging waste water under pressure from an upper portion of said biotreatment chamber; a plurality of superimposed water treatment trays disposed substantially horizontally in said housing of said biotreatment chamber and below said waste water inlet means, said water treatment trays being adapted for retrieval from said biotreatment chamber through said door of said housing unit, each of said water treatment trays having at least one bottom porous section containing an organic contact media, said organic contact media comprising naturally occurring organic vegetative matter, said organic contact media acting to retain and favor growth of microorganisms having the ability to degrade hydrocarbons in said waste water, said water treatment trays being disposed in said biotreatment chamber in a stationary relationship during treatment to permit intimate successive contact of said waste water with said organic contact media on each of said water treatment trays for gradual treatment of said waste water, as said waste water flows downwards in said biotreatment chamber; water outlet means substantially at a bottom of said biotreatment chamber for discharging treated waste water from said biotreatment chamber; air flow means for creating an aerobic environment in said biotreatment chamber, said air flow means being adapted to provide air flow through said water treatment trays in said biotreatment chamber; and air outlet means for removing air introduced in said biotreatment chamber through said air flow means.
2.
The bioreactor unit according to claim 1, wherein said water treatment trays have a wavy-shaped bottom porous section to enhance biological activity of said microorganisms retained by said organic contact media and, when in position in said biotreatment chamber, are in sealing relationship with said biotreatment chamber to prevent seeping of water or gases around said trays and along the walls of said housing unit