Page 74 - March 2020 - WT Site

• This treated water can be used for flushing, car washing, B. Filter Media
gardening cooling tower feed etc.
A septic tank filter is a device inserted in the outlet “T” of the
Detail Description Of Each Unit septic tank. Its purpose is to filter the wastewater from the septic
tank before it discharges to the wastewater land management
A. Septic Tank area. Pressure filters are similar to gravity filters in that they
include filter media, supporting bed, underdrain system, and
1) Introduction A septic tank is a small scale sewage treatment
system common in areas without connection to main sewage control device. The use of pressure filters eliminates the need for
pipes. The settled solids are anaerobically digested, reducing repumping of filtered water.
the volume of solids. The excess liquid, now in a relatively clear
condition, then drains from the outlet into the septic drain field
or leach field. However, when effluent from septic tank is treated
with ozone it can readily be used for household purposes.

2) Working of septic tank

Figure 5: Pressure sand filter

C. Ozone

1) Introduction Ozone is tri atomic Oxygen. O3 is a very strong
disinfectant & oxidant. Any pathogen or contaminant that can be
disinfected, altered or removed via an oxidation process, will be
affected by ozone. It is the strongest of all molecules available
for disinfection. In water treatment ozone is more than twice as
powerful as chlorine and acts 3000 times faster. Ozone can be
used as a disinfectant deodorizer, detoxifier and a coagulant. Due
Figure 4: Working of Septic tank to these properties ozone is widely used in air, water and waste
water treatment in variety of applications.
The septic tank is a buried, watertight container typically made
of concrete, fiberglass, or polyethylene. It holds the waste water 2) Production of ozone
long enough to allow solids to settle out (forming sludge) and
oil and grease to float to the surface (as scum). It also allows
partial decomposition of the solid materials. Compartments
and a T-shaped outlet in the septic tank prevent the sludge and
scum from leaving the tank and travelling into the drainfield
area. Screens are also recommended to keep solids from entering
the drainfield. Newer tanks generally have risers with lids at the
ground surface to allow easy location, inspection, and pumping
of the tank. Figure 5: Production of ozone with corona discharge method

76 Water Today - The Magazine l March 2020