This document discusses various methods for removing color from textile effluents, which is an environmental concern. It covers physical methods like membrane filtration and adsorption. Chemical methods include coagulation and advanced oxidation processes, though they produce sludge. Biological methods like fungal and microbial degradation are most economical. Specifically, phytoremediation uses plants to uptake and degrade dyes, while photodegradation employs TiO2 and radiation like sunlight to break down dyes. Plant surface morphology impacts accumulation and different plant types may work best for specific dyes.
2. • Requirement to minimise environmental release of
colour.
• Source of release of colour - incomplete exhaustion of
dyes onto textile fibre
• Need to reduce the amount of residual dye in textile
effluent - a major concern in recent years.
• An alternative approach to addressing the problem of
colour - effluent treatment methods to remove colour.
• These methods - the cost of the overall process and
some present the complicated - the possible toxicity of
degradation products to be removed.
3. COLOUR REMOVAL
PHYSICAL METHODS
• Different physical methods are also widely
used, such as membrane – filtration processes
(nanofiltration, reverse osmosis,
electrodialysis) and
• adsorption techniques.
4. COLOUR REMOVAL
CHEMICAL METHODS
• Coagulation or flocculation combined with flotation and
filtration, precipitation-flocculation with Fe(II)/Ca(OH)2,
electroflotation, electrokinetic coagulation, conventional
oxidation methods, irradiation or electrochemical processes.
• Chemical techniques - expensive, and although the dyes are
removed, accumulation of concentrated sludge - disposal
problem.
• Recently, other emerging technique - advanced oxidation
processes.
• Although these methods are efficient for the treatment of
waters contaminated with pollutants, they are very costly and
commercially unattractive.
5. BIOLOGICAL METHODS:
• Biological treatment- most economical - when
compared - physical and chemical processes.
• Biodegradation methods- fungal decolourization,
microbial degradation, adsorption by (living or dead)
microbial biomass.
• Bioremediation systems - applied to the treatment of
industrial effluents because many microorganisms such
as bacteria, yeasts, algaes and fungi are able to
accumulate and degrade different pollutants .
7. PHYTO REMEDIATION:
With particular importance to the textile
effluents which contain synthetic dyes.
These compounds can be bioremediated using
plants which have been found to take up the
dyes.
Most of the remediation techniques are much
expensive & affect the ecological system
negatively.
8. Plants - used to remediate such environmental
contaminants - toxic & hazardous to the
ecosystem.
Plants must be chosen - its unique uptake
capacity to accumulate a particular dye,degrade
it - either to utilise it in its metabolism or to
release it as non toxic material.
response of the plants towards the textile dyes
through phyto accumulation, phytosorption &
phytodegradation.
9. PHYTOREMEDIATION METHOD
Phytoaccumu
lation:
Accumulatio
n of the
contaminants
by plants
Phytodegrad
ation:
Degrading
the toxic
contaminants
by the
enzymes
Phytoremedi
ation:
An
ecofriendly
solution for
environment
al pollution
using plants
Phytosorptio
n:
Adsorption
of
contaminants
by dried
plant
biomass
10. Plant surface morphology- important role in
the phytoremediation process.
Accumulation & sorption of the dyes by the
plant occur based on the porosity of the
plants surface.
The dye molecules when accumulated or
adsorbed by the plant biomass, enter the
pores on the plant surface & block them.
11. PHOTO DEGRADATION:
Textile industries produce large volume of
coloured dye effluents which are toxic & non
biodegradable.
Photodegradation was carried out using TIO2
as photocatalyst.
The degradation of dye was carried out using
different sources of energy, like solar radiation
& microwave radiation.
12. Degradation of a photodegradable molecule -
the absorption of photons, particularly those
wavelengths found in sunlight, such as
infrared radiation, visible light, and ultraviolet
light.
Photodegradation - photodissociation, the
breakup of molecules into smaller pieces by
photons.