How to restore the purification capacity of saturated activated carbon?

Activated carbon has a loose and porous structure, and both its outer and inner surfaces have strong adsorption capabilities. However, after a period of use, the pores of the activated carbon become filled with various impurities, reaching saturation and losing their purification ability.
Ineffective activated carbon, after acid washing, alkali washing, and water washing, can remove most of the insoluble inorganic salts, oil stains, and other impurities from the pores, thus being reactivated.

Tools and Materials
Beaker, glass rod, iron plate, alcohol lamp, asbestos net, iron stand, iron ring, graduated cylinder, dropper.
Ineffective activated carbon from the water purifier, 10％ hydrochloric acid solution, 10 ％ sodium hydroxide solution, distilled water, 75 ％ alcohol, “ Original text ” Reagents.

Experimental Procedure
1. Acid Washing
1 Take the ineffective activated carbon from the water purifier, place it in a beaker, and add 10 ％ hydrochloric acid solution until the solution submerges the activated carbon.
2 Place the beaker on the asbestos net of the iron stand, heat the solution to boiling using an alcohol lamp, and stir with a glass rod to dissolve most of the insoluble inorganic salts and other impurities in the activated carbon pores in the acid.
2. Alkali Washing
1 Remove the acid-washed activated carbon from the beaker, rinse briefly with water, and place it back in the beaker. Add 10 ％ sodium hydroxide solution until the alkali solution submerges the activated carbon.
2 Heat the solution to boiling using an alcohol lamp and stir with a glass rod to remove oil stains and other substances from the pores of the activated carbon.
3. Drying
Remove the alkali-washed activated carbon from the beaker, rinse with water, and dry it in the sun or on an iron plate using an alcohol lamp. The activated carbon treated in this way basically recovers its adsorption capacity. Coconut shell activated carbon manufacturer 'How much does coconut shell activated carbon cost' , Wholesale coconut shell activated carbon - Guangzhou Hanyan
4. Testing
1 Dissolve “ Original text ” reagent in 10 ％ hydrochloric acid solution to prepare a solution with a volume fraction of 0.1 ％ “ Original text ” solution.
2 Take the 50mL water flowing out of the ineffective activated carbon water purifier into a beaker and add 2 drops “ Original text ” of the solution, and observe the phenomenon.
The liquid in the beaker turns yellow.
3 Place the activated carbon treated in this experiment into the water purifier, take the 50mL water flowing out of the water purifier again, repeat the above operation, and observe the phenomenon.
The liquid in the beaker is almost colorless.
The above phenomenon shows that the chlorine in the tap water has been basically removed, and the activated carbon has recovered its adsorption capacity.

Explanation and Extension
1 Acid-washed and alkali-washed activated carbon can recover its activity. If further washed with 75 ％ alcohol, the purification effect of the activated carbon will be even better.
2 This experiment reactivated the activated carbon in the water purifier; other ineffective activated carbons can basically be reactivated using this method.
3 After removing the precipitate from the acid-washed or alkali-washed solution, adding a small amount of concentrated hydrochloric acid or sodium hydroxide crystals can allow for continued use.
4 This experiment uses a chemical method to reactivate the activated carbon. We can also use physical methods such as high-speed airflow to remove various adsorbed substances from the surface of the activated carbon to achieve reactivation.