Clarifire

1. PRESENTING BY – NISHTHA YADAW
M.Sc. (R.T.) II SEMESTER
DEPARTMENT OF RURAL TECHNOLOGY AND SOCIAL DEVELOPMENT,
GURU GHASIDAS VISHVAVIDYALAYA , BILASPUR (C.G.)
COURSE CODE – RT – 205 (RURAL WASTE MANAGEMENT)
SESSION – 2018-19

2. CONTENTS
 INTODUCTION
 CLARIFIER
 WORKING
 PRIMARY VS. SECONDARY SLUDGE
 PRIMARY CLARIFIER
 SECONDARY CLARIFIER
 TYPES OF CLARIFIER

3. INTRPDUCTION
Sewage Treatment Plants are installed at various industries for
treating waste before discharging them into water bodies.
The plant receives the waste from domestic, commercial and
industrial sources and removes the harmful materials from the
sewage that damage water quality.
The prime objective of a sewage treatment plant is to make the
industrial effluents free from elements that are harmful for human
and environment.
We offer following equipments:
 Clarifier
 Clariflocculators
 Effluent Treatment Systems
 Water Pollution Control Systems
 Waste Treatment Plants

4. CLARIFIER
 Clarification is the process to remove suspended solids from
water which is done by Clarifier.
 It is the economical and an essential part of effluent treatment
plants and other raw water treatment plants.
 Depending upon the plant, the clarifiers are available in wide
varieties of shapes.
 Clarifiers work on the principle of gravity settling.
 The heavier suspended solids settle in the clarifier due to the
quiescent conditions provided in the Clarification zone.
 The settled solids are swept to the centre well provided for
collection of sludge with help of moving scraper blades.

5. WORKING

6. PRIMARY VS. SECONDARY
SLUDGE
 Sludge refers to the semi-solid residual material which is left
behind from the treatment of wastewater. The two main types
of sludge produced from the wastewater treatment process are
primary and secondary sludge.
 Primary sludge is a result of the capture of suspended solids
and organics in the primary treatment process through
gravitational sedimentation, typically by a primary clarifier.
 The secondary treatment process uses microorganisms to
consume the organic matter in the wastewater. The
microorganisms feed on the biodegradable material in the
wastewater in the aeration tank then flow into a secondary
clarifier where the biomass settles out and removed as
secondary sludge.

7. PRIMARY CLARIFIER
 Primary clarification is the physical treatment process of
removing solids before biological treatment.
 Floatable material (scum) are removed from the surface by
skimmers and settle able solids (sludge) are collected on
the bottom by a rakes.
 The expected range for percent removal in a primary
clarifier is 90% - 95% settle able solids , 40% - 60%
suspended solids.

8. SECONDARY CLARIFIER
 Microorganisms such as bacteria and protozoa can use the
small particles and dissolved organic matter not removed
in primary clarifier as food.
 In a secondary clarifier which operates in the same manner
as the primary clarifier discribed previously. Some of the
solids collected in the secondary clarifier ( return
activated seludge) are sent back to the aeration tank.

10. TYPES OF CLARIFIER
Circular Clarifier
 The Clarifier design can be applied
to water or wastewater treatment
systems.
 It includes a larger influent well to
provide the required flocculation
time.
 Mechanical flocculation is proved
by either concentric ‘stacked’
drives or independent mixers.
 Tanks start at 10 feet in diameter
and larger.

11. Rectangular Clarifier
 The Chain & Scraper Sludge
Collection System provides for
wastewater treatment system.
 commonly used in very large or
space constrained municipal
and industrial spaces, removes
both settled and
suspended solids from liquids.

12. REFERENCES
 Hammer, Mark J. Water and Waste-Water
Technology. John Wiley & Sons (1975) ISBN 0-471-
34726-4, pp. 223–225.
 Metcalf & Eddy. Wastewater Engineering McGraw-Hill
(1972). pp. 449–453.
 Zytner, Richard G. "Solids Separation.“ School of
Engineering, University of Guelph, Ontario, Canada.
Accessed 14 October 2013.

13. Thank You