SPX Cooling Technologies Marley MarPak MXF 3000 - Manual (Page 3)

Fixed Film Process
History
For over 100 years the fixed film reactor
(trickling filter) has been used in wastewater
treatment to reduce the biochemical oxygen
demand (BOD) and for nitrification. As the
wastewater passes down through the trickling
filter, microorganisms on the surface of the
media convert the dissolved organic wastes
and ammonia nitrogen into stable by-products
- carbon dioxide, nitrates, nitrites and biosolids
which are removed by clarification.
Advantages
The advantage of the trickling filter process
over other methods of treating wastewater
include:
1. Lower energy consumption (Fig. 3-1)
2. More resistant to hydraulic and organic
shock loads
3. Simple operational procedures
4. Fewer personnel required to operate
5. Reduces sludge bulking problems
Future
With the advent of the highly efficient modular
60° cross flow media (MARPAK MXF Series), the
trickling filter is a viable alternative for complete
secondary treatment (Figs. 8-1 and 8-2) and
nitrification (Fig. 9-1) of municipal wastewater.
As energy and labor costs continue to increase,
the trickling filter process will become even
more cost effective in wastewater treatment.
1 2 3 4 5 6 7 8
3-1
Relative Energy Consumption
Influent &
Intermediate
Pumping
Secondary
Treatment
Sludge
Treatment
Building
Heating
& Cooling
10ft. Total Head
Aerobic Digestion
Incineration
Extended Aeration
100ft. Total Head
30ft. Total Head
Activated Sludge
Trickling Filter
Preliminary Treatment
Primary Treatment
Thicken & Anaerobic Digestion
Drying Beds
Haul to Landfill
Aerated Ponds
Chlorination
Northern U.S.
Southern U.S.
Source: Water and Sewage Works