Water Treatment Company
Water Treatment Units
 Standard
type of Johkasou unit :
As small –scale Johkasou can be installed on a
household level and treat and discharge wastewater locally , this
have remarkable advantages compared to sewerage systems from the
perspective of protecting the local aquatic environment and cost
benefit performance .
1- low initial investment cost.
2-little topographic limitation .
3-johkasou treated water and sludge are easy to reuse .
4-invaluable contribution to maintaining sufficient water in small
rivers and aquatic environments near inhabited area .
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 Medium
/ large scale Johkasou :
Medium / large scale Johkasou among standard structure types
can be divided into two group : those belonging to the
biological film method group and those belonging to the
activated sludge methods , conventional activated sludge
process and extended aeration process
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 Moving bed bio film –filtration Johkasou:
This process is a combination of a moving bio
film and a bio film filtration process .The treatment method is
divided into two portions
1-The upper portion is filled with granular media and aerated as
that in a moving bed bio film .
2-The lower portion“ the bio film filtration “ is filled with media
for the filtration of suspended solids .
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 Nitrogen removal type
:
A flowchart depicting the nitrogen removal
type Johkasou employing the biological film. The treatment
process adopted is the nitrified water recirculation type
contact aeration process, which is used in the standard
structure type as shown below.
a)All of the Johkasou have a flow equalization function .
b)Newly developed secondary treatment equipments incorporated .
c)Pumps and blowers operated and controlled automatically.
d) Some of the Johkasou are capable of removing BOD and nitrogen
to concentrations of 10mg/L or less .
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 Membrane
reactor :
A membrane reactor
with a micro filtration membrane module is applied to activated
sludge process for separation suspended solids , instead of the
conventional sedimentation tank . The membrane reactor has some
following feature .
I) High water -solid separation
performance:
The water - solid separation performance of membrane modules is
unaffected by settling characteristics of activated sludge or
inflow fluctuation .
II) Reduced biological reactor size :
A membrane reactor can be operated at a high MLSS concentration,
this makes it possible to reduce the size of the biological
reactor and generate less excess sludge .
III) Stabilization of microorganisms :
As the sludge retention time of activated sludge in a membrane
reactor is very long, specific bacteria having lower growth
rates, such as nitrifying bacteria and other special bacteria
that can decompose specific organic matter , can multiply at a
higher rate and achieve a higher concentration .
iV) Advanced treatment of wastewater :
The water that permeates from the membrane module is very clean
, having no suspended solid or coli forms. In the case of
small-scale Johkasou, a membrane module is submerged in the
aeration tank, and permeated water is sucked out by a siphon
system to produce the treated water with BOD .
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Bio film filtration tank Johkasou :
This tank is designed for advanced treatment
of domestic wastewater and for making Johkasou more compact . In
this tank , biological treatment by a medium with biofilm and
physical filtration occur simultaneously .It is filled with
granular or cylindrical media with dimensions of several
millimeters to several centimeters .
This tank functions as a bioreactor , aerating in the upper part
of the tank and filtrating and catching suspended solids in the
under part , performing as the contact aeration tank and the
sedimentation tank in the anaerobic filter- contact aeration
process. Materials for the medium used in the biofilm filtration
tank may be porous ceramic, polystyrene, polyurethane or
polyethylene. A diffuser is installed under the supporter of the
media .
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