Abstract: In this study, we demonstrated the effects of chemical treatments for Halloysite nanotubes (HNTs) under acid and alkaline conditions using sulfuric acid and sodium hydroxide. XRD results indicate that alkaline treatment destroyed the crystalline structure and morphology for HNTs because the XRD spectrum shows the typical peaks for montmorillonite. For the acid treatment using H2SO4 ,XRD spectrum indicates an intensity reduction for the peak (001) showing a lower concentration of aluminium in the structure. Diffuse reflectance analysis shows a reduction of 40 and 15% for reflectance with H2SO4 and NaOH treatments respectively. A terephthalic acid adsorption test was realized with the HNTs, modified halloysites (HNT-H2SO4) and (HNT-NaOH) samples with a kinetic study and it was quantified with UV spectroscopy at 240 nm where results shown a lower adsorption for HNTs treated with H2SO4 in comparison with alkaline treatment and not treated HNT. A decrease of 58% ± 0.3was achieved with the sulfuric acid treatment with not crystalline structure modification using ICP technique to quantify the sample compositions.Keywords: Halloysite nanotubes, acid/basic treatment, aluminium sulfate, physical adsorption, Fourier-transform infraredspectroscopy (FTIR), XRD, diffuse transmittance.