1. BLDEA’S VACHANA PITAMAHA DR. P.G
HALAKATTI COLLEGE OF ENGINEERING &
TECHNOLOGY
CIVIL ENGINEERING DEPARTMENt
seminar presentation
UNDER THE GUIDANCE OF:
prof a.s.arwikar
PRESENTED BY:
muhammed shoaib . A. pathan
usn : 2bl16cv048
3. Contents
• Introduction
• Working and Principle
• Membrane
• Membrane Fouling
• Methods to remove Membrane Fouling
• Cleaning
• Applications
4. Introduction
• Water purification is the process of removing undesirable
chemicals, biological contaminants, suspended solids, and gases
from water.
• The goal is to produce water fit for specific purposes. Most water is
purified and disinfected for human consumption (drinking water),
but water purification may also be carried out for a variety of other
purposes, including medical, pharmacological, chemical, and
industrial applications.
• The methods used include physical processes such
as filtration, sedimentation, and distillation; biological processes
such as slow sand filtersor biologically active
carbon;chemicalprocesses
such as flocculation and chlorination; and the use of
electromagnetic radiation such as ultraviolet light
9. Ultrafilteration system
• Ultrafiltration (UF) is a variety of membrane
filtration inwhich forces like pressure lead to
a separation through a semipermeable
membrane.
11. INTRODUCTION (CONTINUE..)
• This separation process is used in industry and
research for purifying and concentrating
macromolecular solutions, especially protein
solutions.
• Pore diameters in the 10-1000 A range.
12. WORKING ;
• Suspended solids and solutes of high
molecular weight are retained in the so-called
retentate, while water and low molecular
weightsolutes pass through the membrane in
the permeate(filtrate).
14. PRINCIPLE;
• The relationship between the applied pressure on
the solution to be separated and the flux through
the membrane is most commonly described by the
Darcyequation:
• Where J is the flux (flow rate per membrane area)
• TMP is the transmembrane pressure (pressure
difference between feed and
permeate stream)
• μ is solvent viscosity
• Rt is the total resistance (sum of membrane and
fouling resistance).
15. MEMBRANE;
• The membrane used for UF should have;
• High porosity
• Narrow pore size distribution
17. Factors effecting rentity of membranes
1. Size of molecules
2. Shape of the molecule
3. Membrane material
4. Presence of other solutes
5. Membrane configuration
6. Fouling and absorption effects
18. Pore Size of membranes
• UF membrane have pore sizes larger than
Reverse Osmosis Process.
• These membranes are mostly used for
fractionating processes (to separate high
molecular weight solutes from low molecular
weight).
• The pore size of UF membrane ranges from
0.001 micron – 0.02micron.
19. Membrane Fouling
• The major challenge faced in UF is membrane
fouling.
• Overtime the filtrate will accumulate on the
membrane surface and clog the pores.
• Greatly reduces membrane effectiveness and
efficieny.
• Methods have been developed to reduce this
effect for continuous operation.
21. Types of Fouling:
1. Particulate deposition:
• Standard blocking: macromolecules are uniformly deposited on
pore walls.
• Complete blocking: membrane pore is completely sealed by a
macromolecule
• Cake formation: accumulated particles or macromolecules form a
fouling layer on the membrane surface, in UF this is also known as a
gel layer
• Intermediate blocking: when macromolecules deposit into pores or
onto already blocked pores, contributing to cake formation
22. Types of Fouling (Continue..)
2. Scaling:
These inorganic salt deposit can block pores
causing flux decline, membrane degradation
and loss of production. The formation of scale
is highly dependent on factors affecting both
solubility and concentration polarization
including pH,temperature, flow velocity and
permeation rate.
23. Types of Fouling (Continue..)
3. Biofouling:
• Microorganisms will adhere to the membrane
surface forming a gellayer – known as biofilm.
• The film increases the resistance to flow,
acting as an additionalbarrier to permeation.
25. Methods To Reduce Membrane Fouling;
• Optimize pH and ionic strength of the feed
solution to minimize the adsorption or
deposition of the feed materials.
• Select an appropriate pre-filtration procedure or
other means to remove large molecules.
• Select a membrane with an optimum pore size.
• Optimize the operating conditions. This includes
increasing transmembrane pressure to maximize
flux.
26. Cleaning;
• Cleaning of the membrane is done regularly to
prevent the accumulation offoulants .
• Regular backwashing is often conducted
every 10 min for some processesto remove
cake layers formed on the membrane surface.
• By pressurising the permeate stream and
forcing it back through themembrane,
accumulated particles can be dislodged,
improving the flux ofthe process.
27. Cleaning (Continue..)
• Backwashing is limited in its ability to remove more
complex forms offouling such as biofouling, scaling or
adsorption to pore walls.
• These types of foulants require chemical cleaning to be
removed. Thecommon types of chemicals used for
cleaning are:
• Acidic solutions for the control of inorganic scale
deposits.
• Alkali solutions for removal of organic compounds.
• Biocides or disinfection such as Chlorine or Peroxide
when bio-foulingis evident.
28. Applications:
•Water Treatment:
1. Process water (Remove oxides, acids, bases,
pathogens, inorganicsalts etc from raw water)
2. Drinking water (viruses and various
microorganisms are removed)
3. Waste water (Remove Pollution and
reduction of waste from water)
29. Applications (Continue..)
• Other applications include :
• Filtration of effluent from paper pulp mill
• Removal of pathogens from milk
• Fruit juice concentration and clarification
• Dialysis and other blood treatments
• Alcoholic beverage industries
• Vegetable oils
• Sugar industry