Dr. Sami Abdel Azeem

20th Feb, 2013

What is water purification?

Water purification is the transition of dirty harmful (Contaminated) water into clean safe water.

Water purification generally means freeing water from any kind of impurity it contains such as contaminants or micro organisms.

WHY PURIFY WATER?

We purify water to get rid of contaminants that can be detrimental to our health.

To make it safe and palatable for human consumption.

Chemical methods Coagulation, flocculation, combined with flotation and filtration, precipitation, ion exchange.

Physical methods Membrane-filtration processes (nanofiltration, reverse osmosis, electrodialysis, . . .) and adsorption techniques.

Biological treatments Biodegradation methods such as fungal decolorization, microbial degradation, adsorption by microbial biomass.

Adsorption techniques:

Employing solid sorbents are widely used to remove certain

classes of chemical pollutants from waters, especially those that

are practically unaffected by conventional biological wastewater

treatments.

These sorbents must have:

• High thermal stability and

• Small pore diameters,

• High exposed surface area and hence high surface capacity for

adsorption.

• Distinct pore structure which enables fast mass transport.

Oxygen-containing compounds – Are typically hydrophilic and polar, including materials such as Silica gel.

Polymer-based compounds - Are polar or non-polar functional groups in a porous polymer matrix (polyurethane foam).

Carbon-based compounds – Are typically hydrophobic and non-polar, including materials such as activated carbon.

Most industrial adsorbents fall into one of

three classes:

prepared by the coagulation of colloidal silicic acid results in the formation of porous and noncrystalline granules of different sizes. It shows a higher surface area which ranges from 250 to 900 m2/g.

Show high sorption capacity.

Expensive adsorbent.

Silica gel

Silica gel

Developed Silica based Sorbents

SG

OH

OH

OH

Silica Gel

(CH3O)

3 Si CH

2CH

2CH

2 NH

2 SG

OH

O

O

Si CH2CH

2CH

2NH

2

(I)

(I)

O

NO2

CHCl3

(CH3CH

2)3N

SG

OH

O

O

Si CH2CH

2CH

2NH

O

NO2

Na2S

2O

4 SG

OH

O

O

Si CH2CH

2CH

2NH

O

NH2

NaNO2 SG

OH

O

OSi CH

2CH

2CH

2NH

O

N=N Ac

OH

NH2

SG

OH

O

OSi CH

2CH

2CH

2NH

O

N=N

OH

NH2

NaNO2/ HAc

OH

N=N

OHOH

N=N

OH

N=N

HO CH3

H3C

NN

HO CH3

C6H

5

+

APTMS, 20 ml

100 ml dry Toluene

Reflux, 72 h

SG - APTMS

+ Cl - C 120 ml

4 ml

50 C, 48 h5 g

- C

(II)

(II) +

5 g

100 ml H O2

50 C, 24 h - C

(III)

(III) +

3 g

120 ml, 1% HAc

0 - 3 C, 2 h - C

(IV)

+

(IV) +

2-aminophenol (AP)

Acetone

0 - 3 C, 24 h - C

AP - SG

2-Naphthol/

NaOH

Acetylacetone/NaOAC/EtOH

0 - 3 C, 2 h

Pyrazolone/NaOAc/EtOH

SG - WWW-

SG - WWW- SG - WWW-C

C

CO

HPANaph - SG HPAAA - SG HPAPyr - SG

Modified Silica gel (Contd.)

Ligand Element Found RSD

(µg/l) (%)

AP Cu

Zn

Pb

Cd

Ni

HPANaph Cu

Zn

Pb

Cd

Ni

HPAAA Cu

Zn

Pb

Cd

Ni

HPAAPyr Cu

Zn

Pb

Cd

Ni

48.6 7.4

125.2 1.8

3.7 5.2

6.1 1.1

15.0 1.7

47.6 1.2

127.2 4.0

4.5 1.6

5.6 3.9

15.9 3.0

49.5 3.2

126.0 1.6

4.7 3.7

5.9 2.5

16.5 1.4

44.5 1.0

130.0 2.4

4.1 4.8

5.2 1.3

16.0 6.5

Analysis of heavy metals in tap water at fayoum city

Polyurethane foam –Polymeric Sorbents

CH3

CH3

n

C NH

O

O CH2CH

2 O (CH

2CH

2 O CH

2CH

2 O)

NHC CH2CH

2

CH3

n HO CH2CH

2 O (CH

2CH

2 O CH

2CH

2 O) H

N=C=O

N=C=O

C NH

O

WWW

NHC

O

O

WWW

Polyurethane Foam (PUF)

+

Polyol (Polyether Type)

Toluene -2,4-diisocyanate

O

nm

m

NH2

Developed foam based sorbents

PUF

2-aminophenol

Acetylacetone

Pyrazolone

Phenylhydrazone

2-aminothiazole

P-cresol

-CH2-O-CH2-O-CO-NH

NH2

CH3-CH2-O-CH2-O-CO-NH CH3

O

CH3

O

CH3

Acetylacetone

-H2C-O-H2C-O-OC-HN

O

CH3NN

CH3OHCH3

acetylacetone-PUF

1.0 mol L-1

NaNO2

0.1 mol L-1

HCl

3oC

1.0 mol L-1

CH3COONa

50% Ethanol +

PUF-untreated

N NCl

-CH2-O-CH2-O-CO-NH CH3

N NCl

Ph

NH

NH2

Ethanol

OH

-H2C-O-H2C-O-OC-HN

N

CH3

N

N

CH3

Ph

NH

CH3

Heat for 4.0 h

AAPH-PUF

+

phenylhydrazin

Synthesis of Acetyacetone phenylhydrazone-PUF sorbent

Adsorption Isotherm of metal ions by AAPH-PUF

0 200 400 600 800 1000 1200 1400

0

100

200

300

400

500

600

700

800

900

Cu

Zn

Mn

Ad

so

rbed

am

ou

nt,

ug

g-1

Concentraion, ug L-1

Removal of Heavy metals from Water

AAPH˗PUF Sorbent

Metal ion Sample

analyzed

RSD% Found (µgL˗1)

5.8 2.9 4.5

10 80 50

Cu Zn Mn

Drinking

water

The oldest adsorbent known and is usually prepared from coal, lignite, wood etc., using physical or chemical activation method.

AC is highly porous, amorphous solid consisting of micro crystallites with a graphite lattice, usually prepared in small pellets or a powder.

It is non-polar and cheap.

The main drawbacks are that it is reacts with oxygen at moderate temperatures and recycling costs.

Activated carbon

Activated carbon

Low cost activated carbon Agricultural Wastes

Banana peel

Orange peel

Saw dust

Coconut shell

Rice husks

1 2 3 4 5 6 7 8 9 10

0

20

40

60

80

100

Ad

so

rp

tio

n (

%)

Sample pH

4-CP

2,4,6-CP

Nitro-CP

1 2 3 4 5 6 7 8 9 10

0

10

20

30

40

50

60

70

80

90

Ad

so

rp

tio

n (

%)

Sample pH

4-CP

2,4,6-CP

Nitro-CP

Rice husks Bana Peel

Removal of CPs by raw agricultural wastes

Removal of CPs by raw agricultural wastes (Contd.)

0 10 20 30 40 50 60

0

20

40

60

80

100

Ad

so

rptio

n (

%)

Shaking time, min

4-CP

2,4,6-CP

Nitro-CP

0 10 20 30 40 50 60

0

20

40

60

80

100

Ad

so

rptio

n (

%)

Shaking time, min

4-CP

2,4,6-CP

Nitro-CP

Rice husks Bana Peel

Effect of pH on removal of 2,4-Dichlorophenol by AC from chemically activated Rice husks

0,00

10,00

20,00

30,00

40,00

50,00

60,00

70,00

80,00

90,00

100,00

1,38 2,23 6,40 10,31 11,44

Rem

ov

al %

pH value

0

10

20

30

40

50

60

70

80

90

100

25 50 100 150 200

Rem

ov

al %

Initial Concentration of 2,4- DCP (mg/l)

Adsorption isotherm of 2,4-Dichlorophenol by AC from chemically activated Rice husks

Thank you