Liquid waste treatment bioreactor process and apparatus

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The liquid waste treatment apparatus consists of at least one aerobic upflow biofilter, also known as a bioreactor.
Inlets at or near the bottom permit the introduction of (a) liquid waste and (b) air or some other oxygen-containing gas.
An outlet at or near the top permits the removal of treated waste.
The area between the inlets and the outlet is substantially occupied with media.
Another outlet, preferably at or near the bottom, permits the purging, from time to time, of accumulated residue.
The media 14 within the biofilter is preferably tubular, with a diameter of, for example, about 7.
5 cm and lengths according to the dimensions of the bioreactor.
The longitudinal axis of the media is preferably substantially perpendicular to the direction of flow of the waste through the bioreactor.
As illustrated in FIG.
7, the media 14 is perforated, preferably having an open net type surface 30, which reduces clogging by suspended material in the liquid waste, but allows accumulation of biomass within the bioreactor and high oxygen transfer.
The media is preferably, but not necessarily, plastic.
Liquid waste is introduced into the biofilter along with an oxygen-containing gas and forced through the media, for example by one or a combination of a pump and/or blower and/or tube diffuser.
The media allow the microorganisms responsible for treatment of the liquid waste to develop at the media surface forming a biological film.
The oxygen-containing gas bubbling upward through the media provides the oxygen necessary for the growth and survival of these microorganisms.
Biomass accumulates on the perforated media and microorganisms therein.
The organic substances, as measured by the biological oxygen demand in five days, or BOD.
sub.
5, in the liquid fraction of the waste is decomposed by a diverse microbial population that accumulates on the surfaces and in the pores of the media.
In comparison to the conventional technologies which allow BOD loading from 0