Page 61 - Industrial Plants

of the filter using rotating distribution arms, which
can be hydraulically or electrically operated.
“Trickling filters have been a valid
solution for wastewater treatment for
over a century and have benefited
from continuous technological
advancements
Oxygen is supplied to the system through
ventilation openings at the bottom of the filter,
allowing air to circulate freely. The support
structure is typically composed of parallel beams
placed on plastic feet or cement walls.

Advantages of trickling filters

These filters effectively treat wastewater to high
standards while maintaining very low operational
and maintenance costs, thanks to the following
main advantages:
1. Simple and Reliable Process:
• Trickling filters operate as aerobic treatment
system, where microorganisms grow on
structured media made of robust plastic and
biologically remove organic matter from
wastewater. The attached biomass is harder
to be washed away and it is more resistant to
poisoning and process shocks.
• This simplicity contributes to lower operational
complexity and maintenance requirements.
2. Lower energy consumption:
• Unlike more energy-
intensive processes “The trickling filter is a treatment
(e.g., activated sludge system where an active bacterial
systems or membrane biofilm grows on the structured
bioreactors), trickling media fillings
filters are Energy
Efficient because the
A dequate treatment of convection (no need of forced ventilation or
oxygen demand is covered by natural

wastewater is one of the major
aeration) and depending on the geodetical
conditions, pumps can be avoided by
challenges for ensuring safe
designing gravity, water feed.
and sustainable water supply.
Hence, it is essential that
wastewater treatment plants
energy consumption. Moreover no sludge
are energy efficient. Trickling filters have been a • They rely on natural air movement, reducing
recirculation is necessary, thus further
valid solution for wastewater treatment for over a reducing pumping power.
century and have benefited from continuous 3. Durable Components:
technological advancements. They are easy to • The filter medium is durable and long-lasting.
manage, reliable, and energy-efficient, meeting • Maintenance costs related to replacing
the current treatment standards in many countries components are minimal.
with short investment payback times. 4. Moderate Skill Level Needed:
The trickling filter is a treatment system where an • Managing and operating trickling filters
active bacterial biofilm grows on the structured requires a moderate level of technical
media fillings. Wastewater to be purified is allowed expertise: there is no need for chemical
to percolate over these surfaces. The inlet reagents dosing and few mechanical
wastewater is distributed over the upper surface components are used, they have direct and

IndustrIal Plants - May 2024
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