1. Types of Trickling filters
By: Prof. Akshay Chiplunkar

2. Types of Trickling Filters
RIZVI COLLEGE OF ENGINEERING
Types of Trickling Filters
They are classified based on
1)According to Organic & Hydraulic loadings 2)According to the number of units used in series
According to Organic & Hydraulic loadings
Low rate trickling filters 2)High rate trickling filters
3)Intermediate rate trickling filters 4)roughing trickling filters
According to the number of units used in series
Single stage trickling filters 2)Double stage trickling filters
Prof. Akashy Chiplunkar Sub:- EE-I

3. RIZVI COLLEGE OF ENGINEERING
W Rate Trickling Filters (LRTF)
These relatively simple treatment units that normally produce a consistent effluent quality even with varying influent strength. ➢
They are generally not provided with recirculation of effluent. ➢
Depending up on the system, wastewater is applied intermittently ➢
With proper loadings the LRTF, including primary and secondary sedimentation units, should remove from 80 to 85 percent of the applied BOD. ➢
Prof. Akashy Chiplunkar Sub:- EE-I

4. High Rate Trickling Filters (HRTF)
RIZVI COLLEGE OF ENGINEERING
High Rate Trickling Filters (HRTF)
When recirculation is used, the hydraulic loading per unit area of filter media is increased.
As a result, higher flow velocities will usually occur causing a more continuous and uniform sloughing of excess growths.
High-rate trickling filters, including primary and secondary sedimentation, should, under normal operation, remove from 65 to 85 percent of the BOD of the wastewater.
Prof. Akashy Chiplunkar Sub:- EE-I

5. RIZVI COLLEGE OF ENGINEERING
Roughing Filter
Roughing filters are high rate type filters designed with plastic packing.
In most cases roughing filters are used to treat wastewater prior to secondary treatment.
low energy is required for BOD removal of high strength wastewaters as compared to activated sludge process because the energy required is only for pumping the influent wastewater and recirculation flows
Prof. Akashy Chiplunkar Sub:- EE-I

6. RIZVI COLLEGE OF ENGINEERING
Prof. Akashy Chiplunkar Sub:- EE-I

7. Single stage trickling filter
RIZVI COLLEGE OF ENGINEERING
Single stage trickling filter
Here only single filter is adopted When two or more filters are required they will provide in parallel
Generally recirculation is not provided
Prof. Akashy Chiplunkar Sub:- EE-I

8. Single stage filter with recirculation
RIZVI COLLEGE OF ENGINEERING
Single stage filter with recirculation
Prof. Akashy Chiplunkar Sub:- EE-I

9. 2) Double stage trickling filter
RIZVI COLLEGE OF ENGINEERING
2) Double stage trickling filter
This system consist of two filters in series
Here re-circulation of effluent is normally adopted
Prof. Akashy Chiplunkar Sub:- EE-I

10. Two-stage filter with recirculation
RIZVI COLLEGE OF ENGINEERING
Two-stage filter with recirculation
Prof. Akashy Chiplunkar Sub:- EE-I

11. RIZVI COLLEGE OF ENGINEERING
Advantages
 The effluent obtain is highly nitrified and stabilised
 They can remove about 80% of suspended solids and about 80%
BOD
 The rate of loading is in comparison with contact bed process
 It is simple, cheap and does not required any skilled supervision
 They are self cleansing
 Mechanical wear ant tear is less as it contain less mechanical equipments
 It require less electricity power to run mechanical equipment
 The moisture content of sludge obtained from this is as high as 99%
Prof. Akashy Chiplunkar Sub:- EE-I

12. RIZVI COLLEGE OF ENGINEERING
Disadvantages
 High capital costs  The loss of head through the filter system is high thus making the automatic dosing  It requires large area  Final settlement in humus tank necessary  This process may develop odur and fly nuisance
Prof. Akashy Chiplunkar Sub:- EE-I