In this thesis, the surface of multi-walled carbon nanotubes (MWNT)s was functionalized by layered double hydroxides (LDH)s, ZnO quantum dots (ZnO QD)s, and carbon QDs (CQD)s for the homogeneous dispersion of them in the polymer matrix. After surface functionalization of MWNTs, they were characterized by different techniques such as FT-IR, XRD, TEM, TGA, and so on. Then, polyethylene terephthalate (PET) bottle waste was recycled and employed as a composite matrix. A facile method was used to prepare recycled PET (r-PET) reinforced with different fillers. The prepared nanocomposites (NC)s were fully characterized. Morphological investigation represented that the hybrids were well distributed in the r-PET matrix. Due to the low amount of filler, no significant changes were observed in the thermal properties of NCs. It was tried to examine behavior of prepared NCs for removal of pollutants such as cadmium (Cd 2+ ) and methylene blue (MB). Effects of pH, adsorbent dosage, time, concentration, and temperature were investigated on the sorption process. Adsorption isotherms investigation, as well as kinetic studies, were also performed via linear and nonlinear models. Favorable sorption was confirmed by extracted parameters from isotherms. A good relationship with the pseudo-second-order model was represented by the kinetics data for all sorbents. On the other hand, thermodynamic parameters showed physisorption. Overall it can be concluded from the obtained results that a physico-chemical pathways play a key role in this sorption process. r-PET/MWNT/LDH NC could adsorb about 60% Cd 2+ from the aqueous solution after 5 minutes. r-PET/MWNT/ZnO QD NC adsorbed 48% Cd 2+ after 5 minutes. The maximum adsorption capacities of Cd 2+ for sorbents of r-PET/MWNT/LDH and r-PET/MWNT/ZnO QD were found to be 38.86 and 39.94 mg g -1 , respectively. After 1h, r-PET/MWNT/CQD NC separated about 45% dye from water. The maximum adsorption capacity for MB sorption by r-PET/MWNT/CQD sorbent was obtained 9.42 mg g -1 . The resulted NCs had the potential of recycling and reuse for pollutants removal from water. According to these results and their comparison with other sorbents, the fabricated NCs are active reusable sorbents for pollutants adsorption. In fact, the combination of a small amount of expensive CNTs with a cheap PET can direct the scientists to present an effective and low cost sorbents for contaminant elimination.