I would increase the doses of the element to get the asymptotic curve and then calculate the maximum adsorption rate using a Langmuir equation. These doses will be the basis for the next test. be carefull since Cr beaves diffent from Pb.

What chemical form of Cr did you use? If you have an anionic form, adsorption changes if the medium's pH changes.

Lead adsorption usualy increased in alkaline conditions if no other ions (complexing) are present.

My take is to ask you what the purpose of the study is, and on that basis decide what the doses should be, and the spaces between them. My experience is (not with Cr) that at last 7 data points are needed for a good isotherm fit with some replication. I use 10 for PO4.

In my view, it also depends on the nature of adsorbent with emphasis that either increasing its dosage would also be within the permissible limits.

Paul Milham and Rogelio Carrillo González thank you so much for your guidance but by adsorbent dose I meant the weight of my material not the concentration of the heavy metal. I am a bit confused about deciding the adsorbent weight. For this experiment I keep all other parameters constant including pH, time, temperature and concentration of heavy metal. So my query is should I select the weight of material showing more %removal or higher adsorption capacity?

It sounds like you may be interested in removal, i.e., you are doing an industrial engineering study. This is outside my experience.

By the way, I do not believe that the Langmuir maximum concept applies to your conditions.

Paul Milham I am testing my nanocomposite material for removal of heavy metals. In my previous report I represented results both in % removal and adsorption capacity. I am attaching my paper here.

But now I am moving towards making a prototype. Therefore unable to identify should I consider the % removal or adsorption capacity and select material weight on those basis.

I will be grateful if you could advise me on this.

Article Preparation, characterization, and evaluation of multifuncti...

Hello Noor,

I downloaded the previous paper through the library. It's nice work but I did wonder how much Ag and Cu might be released into the environment at the industrial scale.

Industrially, my guess is that you would have two filters operating at any one time in series. In operation, the second would be promoted to first then replaced with a new unit. You'd need some type of indicator to prompt this change.

That's the best I can do, Paul.

Hi Paul Milham

Thank you so much for your valuable insights and guidance. I will take these suggestions under consideration.