The process that the City of Ocoee uses to treat wastewater that comes from residential and commercial sources is called Bio-Denitro process. This process was designed in Denmark and used successfully throughout Europe and eventually introduced into the United States. The City of Ocoee spent a great deal of time researching various systems and the Bio-Denitro was determined to be the best.
(influent) wastewater contains biodegradable and nonbiodegradable
materials, including some chemical compounds. The larger
non-biodegradable materials are removed from the wastewater by
mechanical bar screens. Grit, sand and other small materials are
disposed of at a Class I landfill site.
The cleaned influent water goes into 2 oxidation ditches. Each ditch
holds one million gallons of wastewater but is capable of treating 3
million gallons of wastewater per day. The ditches provide a controlled
environment where microscopic organisms can live, grow and reproduce.
This environment must have oxygen present in the water for respiration;
99% of the incoming wastewater is simply water.
The other 1% is
waste material. This material is food for the bacterial organisms. By
providing a suitable environment for the bacteria to live and grow, and
by bringing the material in contact with the bacteria we have the
beginnings of the wastewater treatment process.
After treatment in the ditches, we need to separate the solids from the
liquids and this process is done in the clarifiers. A clarifier
provides a turbulent-free environment where the solids settle to the
bottom and the water flows from the top. The clarifier begins with 2
flow paths. One is the path that the settled solids take and the other
is the path the water takes. Solids are sent back to the ditches if
necessary, to balance the available food supply. If it is not necessary,
the solids are sent to a digester as waste solids.
function of the digester is to reduce the solids from the liquid to its
most stable condition. There are no food sources introduced at this
stage of processing. The bacteria that are present consume any food that
may have escaped earlier treatment, and without any additional food
they begin to consume each other.
From the digester, the waste
solids are sent to the dewatering process. The press separates as much
water as possible from the mixed liquid and the remaining solids are
pressed into cake. This cake is eventually disposed of through land
application by dumping it into an approved landfill site.
The clear water that leaves the clarifier is passed through a sand
filtering process where any materials that may have escaped from the
clarifier are removed. From the filters, the flow is sent into the
chlorine contact chambers. In these chambers, chlorine is added to
disinfect the water. Once the water has been disinfected, it is useable
for irrigation and is then sent to the above ground reuse storage tanks.
By the time the water reaches the reuse tanks, it is clear and clean
and in such good condition that it can be safely put back into the
ground through irrigation. The City of Ocoee is continuing to install
infrastructure to carry reuse water to residential homes and commercial