This is done to reduce heavy metals ions such as Cr(VI), Cd(II), Ni, from tannery waste water. The removal is done by using natural adsorbents which are inexpensive and plentily available.

1. PAAVAI ENGINEERING COLLEGE
(Autonomous)
NH- 44 (Formerly NH-7), PACHAL,
NAMAKKAL-637018
DEPARTMENT OF CHEMICAL ENGINEERING
REMOVAL OF HEAVY METALS FROM TANNERY EFFLUENT USING
Acacia nilotica & Solanum surattense LEAVES
GUIDED BY; PRESENTED BY;
Mrs. Bharani . P Sarath S.L (16201037)
Assistant professor Akshay Prabhakaran (16201008)
Department of Chemical Engineering Akhil Reji (16201007)
Tamil Selvan .K (16201054)

2. SCOPE
o To reduce Cr(VI), Cd (II), Ni(II) from tannery effluents using natural adsorbents like
Acacia nilotica and Solanum surattense
OBJECTIVES
o To reduce the heavy metal ions( Cr(VI), Cd (II), Ni(II) ) in the waste water
o To extract the adsorbents from leaves
o To analyze the efficiency of adsorbent with effect of adsorbent dose, contact time, pH,
particle size and shaking speed.
o To characterize the metal binding properties of leaves

3. INTRODUCTION
TANNERY INDUSTRY
o Tannery industries is the one of the most polluting industries , there are approximately
30000 tanneries in India mainly located in the states of Tamil Nadu ,West Bengal
Uttarpradesh , Bihar , where they generating about 1,75,000m² waste water per day.
o Approximately about 30-36m3 waste water is discharged to the environment during
processing of every one ton of leather
o The major aim of the leather industry is to convert putrscible animal hide or skin to
leather.

4. TANNERY EFFLUENT
o Tannery waste water are highly complex and are characterized by high content of solids
(fine leather particles, residues from chemical discharge, and some reagents), heavy
metals (Cr, Cd, Pb, Ni, Co, Mn ), oils and grease
o Of the heavy metals present Cr, Cd, Ni are the most polluting metals these metals can
cause disinfections in renal, reproductive and nervous systems and have carcinogenic
effects
o The Cr(VI) concentration in waste water ranges from 2000-5000 mg/L for waste water
discharge
o Cr(VI) is mainly found in tannery effluent as chromate and dichromate ions it is essential
to remove chromium from tannery effluent

5. OTHER TREATMENT METHODS AND DISADVANTAGES
o The major treatment method for removing the contaminants from waste water are
chemical precipitation , membrane filteration , solvent extraction , ion exchange, and
electrolytic reduction
o The above mentioned methods are non-economical and having many disadvantages such
as incomplete metal removing , high reagent , energy requirements and also generation of
toxic sludge or other waste products that may require disposal or treatment

6. ADSORPTION
o Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved
solid to a surface as this process creates a film of the adsorbate on the surface of the
adsorbent
o Adsorption is present in many natural, physical, biological, and chemical system, and is
widely used in industrial applications such as heterogenous catalyst, activated charcoal,
capturing and waste heat to provide cold water for air conditioning and other process
requirements
o The process of adsorption arises due to presence of unbalanced or residual force at the
surface of liquid or solid phase, these unbalanced residual force have tendency to attract
and retain the molecular species with which comes in contact with surface

7. TYPES OF ADSORPTION
o Forces of attraction exist between adsorbate and adsorbent where this force of
attraction happened due to vanderwaal force of attraction which are weak forces or due
to chemical bond which are strong force of attraction
o On the basis of type of forces of attraction existing between adsorbate and adsorbent,
adsorption can be classified into two types;
1. Physical Adsorption (or) Physisorption
2. Chemical Adsorption (or) Chemisorption

8. PHYSICALADSORPTION
o When the force of attraction existing between adsorbate and adsorbent are weak
vanderwaal forces of attraction
o Physical adsorption takes place with formation of multilayer of adsorbate on adsorbent
CHEMICALADSORPTION
o When the force of attraction existing between adsorbate and adsorbent are chemical
forces of attraction or chemical bond
o Chemical adsorption takes place with the formation of unilayer of adsorbate on adsorbent

9. NATURAL ADSORBENT
o The adsorption method is the most useful method to remove heavy metals for obtaining
high efficiency normally activated carbon is used however its high cost restricts large
scale use.
o Here we are using cheap, eco friendly and abundantly available Acacia nilotica and
Solanum surattense leaves as natural adsorbents for removal of Cr(VI), Cd(II), Ni(II).
o Acacia nilotica is used for the treatment of human immune deficiency virus, hepatitis C
virus and cancer. Native to Africa, Middle East and Indian subcontinent.
o Solanum surattense can be used for respiratory disorders, fever, amenorrhea and painful
delivery. Native to South East Malaysia, Australia and in India

10. SCIENTIFIC CLASSIFICATION OF LEAVES
Scientific name Acacia nilotica Solanum surattense
Common name Gum Arabic tree Yellow fruit night shade
Local name (Tamil) Karuvelai Kantakari or Kandankathiri
Family Plantae Solanaceae
Order Fabales Pole moniales
Kingdom Plantae Plantae

11. LITERATURE REVIEW
SI.
NO
TITLE AUTHOR AND
YEAR
DESCRIPTION
1
Removal of Cr(III) by
activated Acacia nilotica
leaf powder
Magan Lal et al.
2013
Chromium removal was done by Acacia nilotica
leaf powder using batch process. Parameters like
adsorbent mass, PH, shaking speed were studied
at different initial Cr(III) concentrations. This
study indicated that the Acacia leaf is an
effective adsorbent. The adsorption of Cr was
tested with Langmiur and Freundlich models
2
Adsorption of chromium
from tannery
wastewater using low
cost spent tea leaves
adsorbent
Md. Abu Sayid
et al.
2018
The experiment results showed that maximum
removal of Cr by spent leaves was 95.42 % at
14g/L of adsorbent dose and PH 10. The
maximum adsorption capacity of Cr on tea was
found 10.64 mg/L. Based on the study tea waste
was considered as low cost, locally and freely

12. 3
Adsorption of Cr(VI)
from aqueous
solution by using
Multani Miti
N. Gandhi et al.
2014
Cr(VI) removal was done using Multani miti. A
stock solution of Cr was prepared by using K2
Cr2O7. The effect of contact time, adsorbent
dosage, pH, temperature were studied between
Multani miti and Cr. These studies reveal a low
cost technique which can be used by small scale
industries which is not only cheaper but only
requires less maintenance. The experiment data
was tested with adsorption isotherm and kinetics
studies
4
Treatment of Tannery
effluent using a Bio-
adsorbent
Mohammad Nazmul
Hossain et al.
2019
Moringa stenopetala seed powder is used as an
adsorbent which can be used for treatment of
tannery waste water. The maximum percentage
of BOD, COD,TDS, turbidity, conductivity and
chromium removal were found to be
82.54%,83.42%, 79.6%, 79.26%, 79.71%,
90.27%. These results suggested the
effectiveness of this natural coagulant in the
treatment of tannery waste water.

13. Biosorption studies
on powder of stem
of Acacia nilotica:
Removal of arsenic
from surface water
Jameel A. Baig et al.
2010
The stem of Acacia nilotica has been
investigated to remove As ions from surface
water sample of different orgins the effects of
various parameters such as pH, biosorbent
dosage, contact time, temeperature on the
biosorption process were systematically
studied experimental data were modelled by
Langmuir, Freundlich and Dubinin –
Ratushevich isotherms. The biomass of Acacia
nilotica was found to be effective for the
removal of As with 95% sorption efficiency at
a conc. of < 200µ/L of As solution.
6
Characterization of
activated Acacia
nilotica seed pods
for adsorption of
Nickel from
aqueous solution
R. Thenmozhi et al.
2015
The use of low cost adsorbent has been
investigated in the removal of Ni ions from
aqueous solution. The adsorption of Ni is
strongly depend on various parameters such as
pH, contact time, temeperature and it was
found out that it has an excellent adsorption
capacity compared with non conventional

14. FLOW CHART
Collection of sample(Acacia nilotica
and Solanum surattense)
Dried
Grinding (powder formation)
Atomic absorption spectroscopy
Extraction(Soxhlet apparatus)
Characterization(FT-IR)
Atomic absorption spectroscopy
Washed with distilled water to remove
the impurities
Tannery effluent treated with
adsorbent
Tannery effluent treated with
adsorbent
AAS (Characterization)
Collection of tannery effluent
Characterization(FT-IR)
Chemically treated adsorbent

15. METHODOLOGY
COLLECTION OF TANNERY EFFLUENT
o Untreated tannery effluent laden with toxic metals has become a very important matter of
concern.
o Representative samples of tannery effluent were collected from E.K.M leather processing
industry.
COLLECTION OF ADSORBENTS (A. nilotica and S. surattense)
o Both the adsorbents have high capacity of removal of Cr.
o Acacia nilotica leaves were collected from Pachal Namakkal district Tamilnadu
o Solanum surattense leaves were collected from Kallakurichi district Tamilnadu

16. PREPARATION OF ADSORBENT
Acacia nilotica
o The collected leaves of A. nilotica was washed under running tap water followed by distilled water
for removal of any compounds.
o It was then shade dried for one week.
o The dried leaves were ground and sieved through a mesh screen and fine biomass was obtained.
o The mixture was impregnated with conc. H2SO4 for 24 h and washed again with distilled
water to attain neutral pH.

17. Preparation of Solanum surattense
o The collected adsorbents was washed thoroughly using distilled water to remove the impurities.
o It is then shade dried and prepared as liquid adsorbent (Soxhlet method).
o The dried leaves are leached using Soxhlet extractor.
o The extracting solvent used is ethyl acetate.
o The extraction was done up to 15 cycles and then it is filtered, the filtrate is used as adsorbent.

18. TREATMENT METHOD
o Adsorption experiments has to be studied in batch process in series of beakers on a
magnetic stirrer.
o A known volume of sample effluent is conducted with varying adsorbents dosages of A.
nilotica and S. surattense (0.2-20 g/L), contact time (30-80 mins), pH (1-10), particle size
(A. nilotica) and shaking speed (50-200 rpm).
NB: pH was adjusted using HCL/NAOH solutions.
o To determine the percentage adsorption of the metal by adsorbent
qe=(co-ce) [where co and ce are the initial and final concentration]
co

19. WORK DONE
o Tannery effluent were collected from E.K.M leather processing industry Erode district.
o Acacia nilotica leaves were collected from Pachal Namakkal district Tamilnadu.
o Solanum surattense leaves were collected from Kallakurichi district Tamilnadu.
o Acacia nilotica leaves were dried and made into powder formation by sieving process and
are chemically activated.
o Solanum surattense leaves were dried.
o Both adsorbents were given for analysis by FT-IR.

20. FUTURE WORK
o Treatment of Tannery effluent with adsorbent(Acacia nilotica and Solanum surrattense)
o Characterization for effluent has to be done(Atomic absorption spectroscopy)

21. REFERENCE
1. Gandhi. N., et al. “Adsorption of chromium(VI) from aqueous solution by using
Multani Miti”, International journal of research in pharmacy and chemistry (2014), pp,
no:168-180, Vol-4(1)
2. Baig T.H., et al. “Adsorption of heavy metal ions by the biomass of Solanum
Elaeagnifolium (silverleaf night shade)”, Conference on hazardous waste research
(1999), pp,no:131-142
3. Jesus M. Arsuaga., et al. “Aqueous heavy metals removal by adsorption on amine-
functionalized mesoporous silica”, Journal of hazardous materials(2009),pp,no:213-221
4. Abdul Q.Shah., et al. “Biosorption studies on powder of stem of Acacia nilotica:
Removal of arsenic from surface water”, Journal of hazardous materials
163(2010),pp,no:941-948
5. Thenmozhi R., et al. “Characterization of activated Acacia nilotica seed pods for
adsorption of nickel from aqueous solution”, International journal of Environment
science and Technology (2015),pp,no:1677-1686, Vol-12

22. 6. Abdella M.H., et al. “ Sunt Bark Powdered Combination Tanning For Manufacturing
of Upper Leather”, International Journal of Engineering and Applied Science (2018),
pp,no:131-142, Vol-5
7. Abhay Raj., et al. “phytotoxicity cytotoxicity and genotoxicity evaluation of organic
and inorganic Pollutants rich tannery waste water from a common effluent treatment
plant”, International Journal of Engineering and Applied Science (2019), pp,no:324-
332
8. Malika.Chabani., et al. “Integration of electro coagulation and adsorption for the
treatment of tannery waste water”, Procedia Engineering (2012),pp,no:98-101,Vol-33
9. B Ogoh., et al. “Tannery waste water evaluation and Remediation : Adsorption of
trivalent chromium using commercial and regenerated adsorbents”, Journal of water
technology and treatment methods(2017), pp,no:2517-7427,Vol-1.1
10. M.N.Hossain., et al. “Treatment of tannery effluent using bio-adsorbent”,
International conference on disaster risk management(2019),pp,no:214