synthesis of fly ash based zeolite for wastewater purification
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Transcript of synthesis of fly ash based zeolite for wastewater purification
Development of a Novel fly ash based Zeolite for treatment of
Waste Water
By
Vinit Sehgal,
B.E. Student,
Department of Civil
Engineering,
BIT-Mesra, Ranchi
6 6 %
2 6 %
3 % 5 %
Thermal
Hydel
Nuclear
RES
Energy status in India
Source:Ministry of power, 2009
www.powermin.nic.in
Preparation of a novel fly ash based zeolite for treatment of waste water
Synthesis of Zeolites & Process Optimization
Zeolite Characterization
Efficiency testing for Cation removal by Ion exchange
Anion removal by Surface Modification
Incorporation of disinfecting agents
Efficiency Testing
Role of Zeolites??
Zeolites are microporous aluminosilicates of the general formula
Mx/n [(AlO2)x (SiO2)y].z H2O where n is the charge of the metal
cation, M n+.
M is usually Na+, K+ or Ca2+ and z is the number of moles of water of
hydration, which is highly variable. In this framework, some of the
silicon atoms are replaced by aluminium atoms. Zeolites are found in
nature and they are also synthesized for catalytic selectivity. Because of
the three dimensional cage like structure, zeolites can be used as ion-
exchange materials and selective adsorbents.
Zeolite can be regenerated using a salt solution which provides a high
concentration of sodium ions to reverse the exchange reaction. In this case
hardness is released as a concentrated chloride
Ca X or Mg X +2NaCl→Na2X + CaCl2 or MgCl2
CaMg
SO42-
2Cl-
2HCO3-
Na2 Z ZCaMg
Na2SO4
2NaCl
2NaHCO3
2+
Adsorption( Molecular Sieves)
Ion ExchangeCaCl2 + Na2Z CaZ+ 2NaCl
MgCl + Na2Z MgZ +2NaCl
CaSO4 +Na2Z CaZ + Na2SO4
Mg2SO4 + Na2Z MgZ + Na2SO4
Ca(HCO3)2Na2Z CaZ + 2NaHCO3
Mg(HCO3) + Na2Z MgZ + 2NaHCO3
Zeolite Synthesis from Fly Ash
Conventional
Hydrothermal TreatmentFusion Membrane Extraction Microwave
Pre-Treatment
FA+NaOH/KOH
Zeolite
50% Conversion
FA+ NaOHPellets
Sodium Silicate
Dissolve in Alkaline Solution
Hydrothermal Treatment
50% Conversion
Silicone Extraction
Fusion
Hydrothermal Treatment with addition of AlumninateSolution
High Purity
5500cReflux & Stirring
FA+ 2M NaOH
Microwave Heating for 2 hrs
Hydrothermal Treatment
Centrifugation
Drying & Crystallization
Alkali source: NaOH/KOH
FA slurry with Solid:liquidratio=140gm:350ml.
Refluxed for 98hrs under strong agitation and at 383 K temp. till the pH becomes neutral
Combination of Conventional and microwave synthesis
Increase in Porosity and hence high CEC values
Better Quality of Zeolites
High CEC
pH control
Effect of Time, Temp and Base
Process Optimization
0.0 0.2 0.4 0.6 0.8 1.0 1.2
25
30
35
40
45
50
55
Turb
ity
Concentration(gm/800 ml)
B
450 500 550 600 650
0.2
0.4
0.6
0.8
1.0
Wastewater
Zeolite treated water( )
Abs
orba
nce
(w.r
.t di
stil
wat
er)
Wavelength (nm)
Dosage Fe(III) concentration % removal
0% 0.8ppm __________
0.025%0.2ppm
75%
0.037%BDL
100%
0.050%BDL
100%
0.062%BDL
100%
Thank you……