Nano-particles discharged through anthropogenic activities contaminate the hydrosphere which create complications include bioaccumulation and bio-toxicity. Destabilization of nano-particles suspension is a challenging task. The present study is a successful attempt towards destabilization of aqueous suspension of multi-walled carbon Nano-tubes (MWCNTs) by a functionalized cationic polymeric flocculant. The flocculant was fabricated by microwave-assisted polymerization of diallyldimethylammonium chloride (DADMAC) on gum tragacanth. The grafted chains of poly(DADMAC) enhance the water solubility and functionality of the synthesized graft copolymer. The flocculation efficacy of the product has been studied in kaolin suspension and in destabilization of aqueous suspension of MWCNTs through standard jar test procedure. The optimal dosage of GT-g-P(DADMAC) as flocculant in MWCNTs suspension has been found at 1.875 ppm and in kaolin it was 1.25 ppm. (C) 2017 Elsevier Ltd. All rights reserved.