Usually plant waste, agricultural wastes, biomass in general are used. It is customary to grind and the material is usually activated using sodium hydroxide, sulfuric acid, or sodium citrate, this treatment activates the active sites (which it does is hydrolyze), which can improve the adsorption if they are to be used in water treatment.

There are a lot of papers to depcit the carbon materials for water purication,you can make a reserch in detail.

Hi Balli,

You can refer to this book chapter by Gülten Gürda and Shokat Sarmad

" Natural Composite Membranes for Water Remediation: Toward a Sustainable Tomorrow "

then in table 2, you will find Summary of natural polymer composite membranes where you can find the references papers and look for the material and method section.

Chapter Natural Composite Membranes for Water Remediation: Toward a ...

besides, there is good review by Carpenter et al which I think could be helpful:

"Cellulose Nanomaterials in Water Treatment Technologies"

http://pubs.acs.org/doi/abs/10.1021/es506351r

I hope it will help

Amin