ADSORPTION

Activated CarbonWhat is Adsorption?• Organic molecules bond to the internal

pores of activated carbon

Some Definitions

• Adsorption• Absorption• Sorption• Adsorbent• Adsorbate

Applications• Drinking water treatment

• Groundwater remediation

• Industrial wastewater treatment

• Polishing of treated municipal waste

• In a variety of gas-phase applications

Activated CarbonThe Three Types/Forms of AC

Powdered Granular Pelleted / Extruded

Activated CarbonWater Treatment Methods for GAC & PAC

Activated carbon is prepared in two steps

• Carbonization step

• Activation step:– Macropores: >25nm– Mesopores: >1 nm and <25nm– Micropores: <1nm

Activation Types

• Steam activation

• Chemical activation

15

-0,04-0,035-0,03

-0,025-0,02

-0,015-0,01

-0,0050

3 4 5 6 7 8 9pH

Sur

face

Cha

rge,

mm

ol/m

g

Raw Water Ozonated Water

Biologically Treated Water Ozonated - Biologically Treated Water

Charge on NOM

-0,4

-0,3

-0,2

-0,1

0

0,1

0,2

0,3

0 2 4 6 8 10 12

pH

Sur

face

Cha

rge,

meg

/g

Row Supra CAgran Norit 1240 HD 4000

pHPZC

pHPZC

Norit 1240

8.90

Row Supra

8.95

HD 4000 6.50CAgran 4.20

The point of zero charge (pHPZC) pH at which the GAC surface charge =0pH> pHPZC (-) chargepH< pHPZC (+) charge