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……