MANYETİK KİTOSAN-HALLOYSİT NANOKOMPOZİTLERİN ÜRETİLMESİ VE KARAKTERİZASYONU: Cr VE METİLEN MAVİSİ ADSORPSİYONUNUN İNCELENMESİ

Abstract

The aim of the thesis is to remove Cr (VI) heavy metal and cationic dye methylene blue, which are toxic and permanent even in low concentrations in the industrial wastewater, by making nanocomposite with magnetic halloysite nanotubes and biopolymeric chitosan (KTS). The magnetic properties of pure halloysite nanotubes (HLT) were achieved by using the co-precipitation method and magnetic halloysite (MHLT) nanotubes were synthesized. MHLT nanotubes were made into nanocomposites with KTS biopolymer and characterization studies were carried out. Characterization of MHLT-KTS nanocomposites and pure states of the components forming the nanocomposite were performed by FT-IR, TGA, SEM, TEM, BET, VSM, particle size analysis. Cr (VI) and methylene blue adsorption on MHLT-KTS nanoparticles were investigated as a function of medium pH, amount of adsorbent, the ratio of the components forming the nanocomposite material, and the initial concentration. The optimum conditions for Cr (VI) adsorption on the MHLT-KTS nanocomposites were pH 5,0, 150 mg MHLT-KTS and MHLT-KTS mass ratio 1:2. The maximum adsorption efficiency was found to be %77,63 for Cr (VI) adsorption at an initial concentration of 10 mg/L. The optimum conditions for methylene blue adsorption on MHLT-KTS were pH 8,0, 25 mg MHLT-KTS and MHLT-KTS mass ratio 2:1. The adsorption equilibrium data obtained from Cr (VI) adsorption and methylene blue adsorption studies on MHLT-KTS were used to investigate the compatibility of Langmuir, Freundlich and Redlich-Peterson models. It was found that Cr (VI) and methylene blue adsorption kinetics on MHLT-KTS nanocomposites are compatible with pseudo second-order models for both components. In this thesis study, besides Cr (VI) and methylene blue single systems, the adsorption of binary systems containing both Cr and methylene blue was investigated and adsorption balance was investigated, its compatibility with adsorption models for binary systems was evaluated.