a powerpoint presentation based on a review paper mainly discussing about the new alternative adsorbent from lignocellulosic materials.

1. Removal of Colour From Dyes in
Water and Wastewater Using Leaves
of Plants as Adsorbents:
A Review of Pre-treatment Methods
Nadirah Ismail
Chemistry Department, Faculty of Science
Universiti Teknologi Malaysia
IWA
Young Water Professionals 2015

2. William Henry Perkins (1838–1907)
 Accidently discovered the first
synthetic dye (at 18 y.o)
 Aniline purple
 From chemicals derived from
coal tar
 From this grew the highly
innovative chemical industry
of synthetic dyestuffs

3. Definition
• Coloured substances that when applied to fibers,
give them a permanent colour which is able to resist
fading upon exposure to sweat, light, water,
chemicals, oxidizing agents and microbial attack.
Characteristics
• Synthetic origin
• Complex aromatic structure
• Stable in the environment
• Metabolites are toxic
• Threat to environment and organisms

5. The Technologies
Treatment methods for textile effluents
Chemical methods Physical methods Biological methods
oxidation ozonation
Filtration
Coagulation/
flocculation
adsorption
microbes
enzymes

6. Adsorption
 Accumulation of the molecular species at the
surface rather than in the bulk of the solid or liquid
is termed as adsorption.
 The phenomenon of attracting and retaining the
molecules of a substance on the surface of a liquid
or a solid resulting into a higher concentration of
the molecules on the surface is called adsorption.
 A chemical process that takes place when adsorbate
accumulates on the surface of a solid (adsorbent),
forming a molecular or atomic film.
 It is a surface phenomenon.

7.  Simplest
 Low capital and operating costs
 Rapid kinetics of adsorption and
desorption
 No sludge production
 Can have good physical properties
 Adsorbents are easily available

8. Activated Carbon
Well
established
Capable to
adsorb various
organics and
metals Porous
structure
High specific
surface area =
Large sorption
capacities
*BUT, activated carbon for
commercial scale pollutant removal is
quite expensive!

9. Alternative adsorbents
“Depleting natural resources, growing environmental awareness and
economic considerations are the major driving forces to utilize
renewable resources such as biomass for various applications”
(Narendra Reddy & Yiqi Yang, Biofibers from agricultural byproducts for industrial applications, 2005)

10. Low cost alternative adsorbent
 Originated from agricultural / domestic/
industrial waste.
 Lignocellulosic wastes: plant biomass wastes
that are consisted of cellulose, hemicelluloses
and lignin.
 Such as sawdust, grasses, stalks, nutshells,
bagasse, leaves, and peelings.

11. Alternative Adsorbents
Banana stalk Peanut hull Plum kernels Mango seed
kernel
Coconut husk Neem leaf
powder
Sugarcane
dust
Tea waste
Rice hull Corn cob Sago waste Degreased
coffee beans
Banana peel Duckweed Sugar beet
pulp
Rice bran
Orange peel Apricot
stone
Lemon peel Soybean hull
Guava leaf
powder
Sunflower
stalks
Jute stick Bamboo dust
Almond shell Cotton
stalks
Raw barley
straw
Hazelnut shell Rattan
sawdust
Durian shell

14. Malachite
green
Crystal
violet
Methylene
blue
Nirgudi leaf,
Kammoni leaf,
Pineapple leaf
Mangifera Indica (Mango)
leaf, Calotropis procera
leaf
Gulmohar leaf,
Posidonia oceanica
leaf, Pineapple leaf
Pineapple
leaf
Mangifera
Indica
Calotropis
procera
Posidonia
oceanica
Application of plant leaf
waste as biosorbent

15. X-ray Diffraction
(XRD)
Scanning Electron
Microscopy (SEM)
Surface area, pore
size distribution
Fourier transform
infrared
spectroscopy (FTIR)
Tools
Characterization of
lignocellulosic materials

16. Physical treatment
WASH – DRY – CRUSH - SIEVE
Pre-treatment methods

17. Chemical
pretreatment
Formaldehyde
Sulphuric
acid
Hydrochloric
acid
Nitric acid
Sodium
hydroxide
Formaldehyde has
been applied to
Sargassum binderi
to avoid organic
leaching that may
lead to secondary
pollution that might
devastate the
biosorption process
(Pei et al., 2009).
The chemical
treatments
enhanced the
adsorption kinetics
of Reactive Red 228
compared to
untreated Posidonia
oceanica (Ncibi et al.,
2007).

18. In the case of
Posidonia oceanica,
four types of chemical
treatments were
introduced i.e.
modification with 0.2
M nitric acid, 0.2 M
phosphoric acid,
sodium hypochloride
and 30% (v/v)
hydrogen peroxide
(Ncibi et al., 2007).

19.  With chemical
modification, adsorbent
will experience good
enhancements in pores.
 When tea waste being
treated with 0.5M NaOH,
gap between pores like
honeycomb shape was
observed under scanning
electron microscope
(Nasuha and Hameed,
2011).
COVERED WITH MB

20. Physicochemical pre-treatments
 Another activation route that could give improved leaves’
pore structure
 Involves the chemical agents such as alkali and mechanical
actions.
 Milling or extrusion of lignocellulosic biomass with the aid
of alkali.
 Mainly to destroy lignin structure

21. (d)
Wash
Dry
Grind & Sieve

22. Chemical treatment of adsorbent
 Methanol to remove inorganic and organic matter from
the surface of sorbents.
Deionized
water
Acid
treatment
Methanol

23. Adsorption
experiments
Adsorbent saturated
with dye
(Reactive Red 198)

24.  Untreated leaves has relatively smooth surface while the
physico-chemically treated leaves exhibits rougher
surfaces.
 Therefore, was proved to be a good activating agent to
develop high surface area adsorbent

25. Lignocellulosic materials

26. Adsorption
pH of
adsorbate
Adsorbent
Dosage
Contact
time
Factors affecting dye
adsorption onto adsorbent

27. High solution pH solution results in an
increase in the percentage of cationic
dye removal because the positive charge
on the solution interface will decrease
and the adsorbent surface appears
negatively charged.
At higher solution pH, electrostatic
repulsion is found between the
negatively charged surface and dye
molecules, thus decreasing the
adsorption capacity and percentage
removal of anionic dyes
pH
Low pH solution
results in an
increase in the
percentage of
anionic dye removal
because of the
electrostatic
attraction between
anionic dye and the
positive surface
charge of the
adsorbent
pH

28. In general, the dye removal
percentage is increasing with
the increase of the adsorbent
dosage
When excess adsorbent
dosage is used, a significant
portion of the adsorption
sites remain unsaturated.
This obviously leads to low
specific adsorption capacity.
Dosage When the adsorbent dosage
was lowered, the number of
active sites saturated with
dyes increased; therefore,
specific uptake also
increased
Dosage

29. At higher contact time, the
rate of adsorption
decreases, gradually
leading to equilibrium due
to decrease in total
adsorbent surface area and
less available binding sites
The decrease in dye
removal with time may be
due to aggregation of the
dye molecules around the
adsorbent particles.
Time

30. Plant leaves-based adsorbent offers many
attractive features such as outstanding
adsorption capacity for many dyes, low in
costing and environmental friendly.
FUTURE RESEARCH: Investigation of these
materials with real industrial effluents,
recovery of used plant leaves-based
adsorbent, regeneration study and
continuous flow study.
It offers significant advantages over
currently available adsorbent and in
addition contribute to agricultural waste
minimization strategy.
Conclusions
Thank You