40692328 trickling filter
TRANSCRIPT
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 1/37
Presented by
Pradeep.H
Co-ordinated by Dr. Prem raj pushpakaran
Asst.Professor
School of Biotechnolgy
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 2/37
Clarifier
General overview of waste water treatment
Secondary Sludge
Primary Sludge
Clarifier
Raw Wastewater Influent
PRIMARY
DISINFECTION
BiologicalTreatment
System
SECONDARY
Clean Wastewater EffluentDischarge to Receiving Waters
Preliminary Residuals
(i.e., grit, rags, etc.)
A
B
C
Wastewater TreatmentResiduals
BiosolidsProcessing
and Disposal
(e.g., attached-grwothSuspended-Growth,Constructed Wetland, etc.)
Clarifier
PRELIMINARY
Usually to Landfill
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 3/37
Introduction
y Waste refers to unwanted residues that are usually perceived of
negative value
y Waste cause hazards to human health, harm to living resources
and ecological systems, damage to structures and amenities or
that interfere with the legitimate uses of the environment.
y Waste management becomes significant.
y Biochemical wastes include organic wastes,Industrial wastes,
Agricultural wastes etc.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 4/37
THE MAIN OBJECTIVE of any waste treatment system is removal of
organic and inorganic impurities from water.
Insoluble: By physical separation.
Soluble: 1. Inorganic - chemical treatment.
2. Organic - Biochemical treatment.
The basic reaction in the biochemical operation is:Organic waste + living microorganisms + Oxygen C02 + H20 + more
organisms
This reaction can be carried out in different reactors and the processes are
classified as: Aerobic digestion.
Activated sludge process.
Anaerobic digestion.
Trickling filters.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 6/37
Trickling filter systemThe components of a complete trickling
filter system are: fundamentalcomponents:
A bed of filter medium upon which a
layer of microbial slime is promoted and
developed.
An enclosure or a container whichhouses the bed of filter medium.
A system for distributing the flow of
wastewater over the filter medium.
A system for removing and disposing of
any sludge from the treated effluent.
The treatment of sewage or other
wastewater with trickling filters is
among the oldest and most well
characterized treatment technologies.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 7/37
Biological wastewater (WW) treatmenty To remove the suspended solids & the dissolved
organic load from the WW by using microbialpopulations.
y The microorganisms are responsible fory degradation of the organic matter
y they can be classified intoy aerobic (require oxygen for their metabolism)
y anaerobic (grow in absence of oxygen)y facultative (can proliferate either in absence or presence of oxygen).
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 8/37
Biological wastewater (WW) treatmenty If the micro-organisms are suspended in the WW during
biological operationy suspended growth processes
y Recycling of settled biomass is required.
y While the micro-organisms that are attached to a surfaceover which they growy attached growth processes
y The biomass attached to media (ex. rock, plastic, wood)y Recycling of settled biomass is not required.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 9/37
Attached Growth Process What can this process do?
1. Remove Nutrient
2. Remove dissolved organic solids
3. Remove suspended organic solids
4. Remove suspended solids
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 11/37
Attached Growth Process
y Trickling filter (TF)y Rotating biological contactor (RBC)
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 14/37
Trickling Filter Process
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 15/37
Design considerationy Influent wastewater characteristics
y Degree of treatment anticipated (BOD & TSS removal).
y Temperature range of applied wastewater
y
Pretreatment processesy T ype of filter media
y Recirculation rate
y Hydraulic and organic loadings applied to the filter
y Underdrainage and ventilation systems
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 16/37
Trickling Filter (TF)- side viewy TF consists of:
y A rotating arm that sprays wastewater over a filtermedium.
y Filter medium: rocks, plastic, orother material.
y The water is collected at thebottom of the filter for furthertreatment.
Wastewater
rotating distributor arms
Packing
media
Underdrain
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 17/37
Design consideration - Pretreatment
y Trickling filters shall be preceded by primary clarifiersequipped with scum and grease collecting devices, or othersuitable pretreatment facilities.
y If fine screening is provided the screen size shall have from0.03 to 0.06 inch openings.
y Bar screens are not suitable as the sole means of primary treatment.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 18/37
Filter mediay Crushed rock
y Durable & insoluble
y Locally availabley But, reduce the void spaces for passage of air
y Less surface area per volume for biological growth
y Plastic mediay Random packing media
y Modular packing media
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 20/37
Design consideration - Filter mediaThe ideal filter packing is material that
y has a high surface area per unit of volume
y is low in costy has a high durability
y has a high enough porosity so that clogging is
minimizedy provides good air circulation
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 21/37
Flow Diagram for Trickling Filters
R ec cle
Primar
clarifier Tric li
filter
Fi al
clarifier
Waste
sl e
Fi al
effl e tI fl e t
Q
Qr
Recir cul tion= A portion of the TF effluent recycled through the filter
Recir cul tion r tio (R) = returned flow (Qr)/ influent flow (Q)
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 22/37
Trickling Filter Process
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 23/37
Design consideration - Recirculation
y Why is recirculation required?
y maintain constant wetting rate
y dilute toxic wastes
y increase air flowy recirculation flow dilutes the strength of raw
wastewater & allows untreated wastewater to bepasses through the filter more than once.
y A common range for recirculation ratioy 0.5~3.0
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 26/37
Ventilation systemsy In TF system,
y Air is supplied by natural draft or forced draft fan.
y The forced draft fans have been applied in order to providethe adequate oxygen.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 29/37
Single stage
PC SCTF
PC SCTF
PC SCTF
a.
b.
c.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 30/37
Two stage
PC SCTF
PC SCTF
TF
TF SC
PC SCTFTF SC
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 35/37
Advantages of Trickling filtration plant y Simple and reliable process that is suitable in areas where large tracts of land
are not available for a WSP treatment systemy Effective in treating high concentrations of organic material depending on the
type of media used;
y Very efficient in removal of ammonia from wastewater;
y Appropriate for small- to medium-sized communities
y
With the introduction of plastic filter media to replace the rock media, speedcontrol, and more reliable rotary distributor mechanisms, the performance of trickling filters has been greatly enhanced.
y Ability to handle and recover from shock loads
y Relatively low power requirements; They require power for pumping only anddo not need large power-hungry aeration blowers. From motor-driven rotary
distributors are powered by fractional horsepower electric motors.y They produce less sludge than suspended-growth systems. The sludge tends to
settle well because it is compact and heavy.
8/8/2019 40692328 Trickling Filter
http://slidepdf.com/reader/full/40692328-trickling-filter 36/37
Dis v t es f rickli filtr ti l t
y Additional treatment may be needed for the effluent to meet strict dischargestandards;
y generates sludge that must be treated and disposed of;
y
Regular operators attention is needed;y Relatively high incidence of clogging;
y Relatively low loadings required depending on the media;
y Limited flexibility and control in comparison with activated sludge processes.They require high maintenance costs of rotary distributor center mechanisms. Any maintenance service for the rotary distribution mechanism would require
a crane and complete removal of the rotary distributor mechanism, guy rods,and arms.