Adsorption

Question 1

Exam question

Explain briefly the basic principles of adsorption and mention the mostly used adsorbent and discuss how it is produced.

Answer 1

Adsorption is a process in which molecules in solution are attracted to a surfaces in contact with solution, this attraction is done either by chemical bonding or van der Waals attraction.
The mostly used adsorbent is activated carbon.
Activated carbon is prepared by the destructive distillation of organic solids which is followed by driving off volatile components (through activation) to form a porous skeleton.

Question 2

explain briefly how carbon is activated and regenerated?

Answer 2

The carbon is activated by passing steam (750-950) in an Oxygen depleted atmosphere with dehydrating agent.
Regeneration of carbon is performed upon exhaustion of the bed by drying the carbon at 100 deg celsius for 15 min. Then pass steam at 800 Deg celsius for 10 min and quench in water.

Question 3

Explain briefly factors affecting the rate of adsorption?

Answer 3

The rate of adsorption is dependent on 
pH
temperature
initial concentration
molecular size 
molecular weight and structure

Question 4

Discuss briefly how activated carbon is found and how i is used

Answer 4

Activated carbon is found in the form of granules or powder. When in the form of granules, they are used as filters medium. The powder form is added and mixed in settling tanks then removed by filtration.