Powder activated carbon is generally less than 0.075 mm in size and thus has an extremely high ratio of area to volume. and thus has an ... and, after a suitable contact time, it is removed by clarification or filtration. . Activated carbon is also used in the treatment of industrial waste water due to its ability to adsorb a wide variety of pollutants, including aromatic compounds, hydrocarbons, detergents, soluble dyes, chlorinated solvents, phenols, and hydroxyl derivatives. A minimum contact time of about 15 minutes is required for most taste and odor compounds; however, significantly longer contact times may be required for methyl-iso-borneol (MIB) and geosmin removal. The Powdered activated carbon (PAC) should not be coated with coagulants or other water treatment chemicals before the PAC has had sufficient contact time with the source water. Also, PAC should not be added concurrently with chlorine or potassium permanganate as these chemicals will adsorb to the PAC. PAC is usually added at the head of the plant to provide the longest contact time possible before applying other treatment chemicals. Higher PAC dosages may be necessary if PAC is added later in the treatment process to account for reduced contact times and interference with other treatment chemicals.

Dear Ghazaleh Chegini It is not universal for all types of PAC derived from different sources. Contact time is affected by the surface area, pore size, pore volume, contaminant initial concentration, contaminant molecular size, pH of solution, source of PAC precursor and many others. However, in my personal opinion, it takes more time for PAC to reach equilibrium compared to juvenile adsorbents.

I completely agree with @ Jehanzeb Ali Shah. I would like to add to factors affecting sorption by PAC: the starting and requested concentration of pollutant, polarity of pollutant. Very important is quality of PAC, because the quality is changing even if the PAC is from one producer.

Best regards

Vit

Powder activated carbon is generally less than 0.075 mm in size and thus has an extremely high ratio of area to volume. and thus has an ... and, after a suitable contact time, it is removed by clarification or filtration. . Activated carbon is also used in the treatment of industrial waste water due to its ability to adsorb a wide variety of pollutants, including aromatic compounds, hydrocarbons, detergents, soluble dyes, chlorinated solvents, phenols, and hydroxyl derivatives. A minimum contact time of about 15 minutes is required for most taste and odor compounds; however, significantly longer contact times may be required for methyl-iso-borneol (MIB) and geosmin removal. The Powdered activated carbon (PAC) should not be coated with coagulants or other water treatment chemicals before the PAC has had sufficient contact time with the source water. Also, PAC should not be added concurrently with chlorine or potassium permanganate as these chemicals will adsorb to the PAC. PAC is usually added at the head of the plant to provide the longest contact time possible before applying other treatment chemicals. Higher PAC dosages may be necessary if PAC is added later in the treatment process to account for reduced contact times and interference with other treatment chemicals.

Dear all, thank you for your replies. I produced more than 50 samples of activated carbon and trying to prioritize them for water treatment application.

I am guessing that more than 2 hours of contact time for any pollutant won't be ideal.

Thank you for your insights on this.

Dear Ghazaleh , i agree Ms Pushpa Jna. You must conduct experiments in batch mode then in continuous mode in order to be able to extrapolate your results on the industrial scale. D'ont Forget to work with real water samples.

I am also interested.

Dear Ghazaleh Chegini ,

I agree with previous suggestions and I am sure you got the idea. In my opinion, I would also suggest you to first conduct a kinetics study (time bound study) in batch mode via keeping other parameters such as activated carbon dose, initial solution pH, initial concentration of targeted pollutant and reaction time constant.

Also, try to simulate waste water conditions properly to get positive and close results with real waste water.

Regards

Amita

It depends on several parameters including temperature, concentration of contaminant and the mass of activated carbon.

I agree with Dr J. Ali Shah for his nice explanations. In addition, to me, it depends on the characteristics as well as intensity of waste water together with the nature of organic compounds present in waste water.