The role of nanoparticles (NPs) in the enhancement of thermal, wettability and adsorption properties of chitosan (CS) was inspired by loading of CaCO3 modified with diacid (DA) based on L-phenyl aniline (2-8 wt%) within the CS by ultrasound agitation. The diameter of CaCO3-DA into the CS extended from 40 to 70 nm. A thermal test on the CS/CaCO(3)DA nanocomposite (NC) 2 wt% revealed that T5 (temperature with 5% weight loss) was increased up to 312 degrees C, which is twice the value of the pure polymer. The wettability property of the CS/CaCO3-DA NCs was transformed from hydrophilicity to hydrophobicity as the CaCO3-DA NPs concentration was increased. It is due to decrease of the accessibility of the CS polar groups to water. The CS/CaCO3-DA NC 5 wt% was selected as the adsorbent for uptake of metal ions from the wastewater. It showed maximum adsorption capacity of 21.74 and 29.41 mg.g(-1) for Cu(II) and Cd(II), respectively. These are attributed to strong complexation reaction between the metal ions and functional groups in the obtained NC.