Pembuatan dan Karakterisasi Bioadsorben Polimer Nanokomposit Cellulose Nanocrystal-g-Poly(Acrylamide-co-Graphene Oxide) untuk Penyerapan Logam Berat Pb (II), Cu (II) dan Cd (II) pada Limbah Industri

Abstract

The removal of heavy metals in industrial wastewater by adsorption method using nanocomposite bioadsorbent of nanocrystalline cellulose (CNC) functionalised with graphene oxide was able to reduce the content of Pb, Cu and Cd metals. This study used bioadsorbent from sugarcane bagasse isolated into cellulose and hydrolysed with 40% sulfuric acid to produce nanocrystalline cellulose and characterised to examine the particle size using PSA (Particle Size Analyzer). In the grafting process, graphene oxide was varied by weight of 0, 20, 40, 60 and 80 mg and freeze drying was carried out to formed hydrogels and obtained 5 hydrogel models as adsorbents for the removal of Pb, Cu and Cd metals. This study aims to determine the efficiency of the swelling kinetics process for Pb, Cu and Cd metals, to analyse the adsorption isotherms and kinetics of the hydrogel adsorbent in batch. The resulting hydrogels were characterised using Fourier-Transform Infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Thermal Stability (TG/DTG). The swelling kinetics process was carried out with variation of time and pH. The obtained hydrogels were able to increase the adsorption capacity at pH 6-7. Adsorption of Pb, Cu and Cd metals demonstrated that the kinetis data followed a pseudo second-order equation, while the adsorption isotherm model followed the Langmuir model. The maximum adsorption capacity is obtained in hydrogel CNC-g-P(AM/GO-0) for Pb (149.99 mg/g), Cu (193.03 mg/g) and Cd (176.73 mg/g), hydrogel CNC-g-P(AM/GO-20) for Pb (132.45 mg/g), Cu (133.5119 mg/g) and Cd (156.8 mg/g), hydrogel CNC-g-P(AM/GO-40)metals Pb (121.74 mg/g), Cu (111.46 mg/g) and Cd (135.89 mg/g), hydrogel CNC-g- P(AM/GO-60) for Pb (129.75 mg/g), Cu (94.07 mg/g) and Cd (114.85 mg/g), hydrogel CNC-g-P(AM/GO-80) for Pb (163.09 mg/g), Cu (87.03 mg/g) and Cd (108.7 mg/g). The results of this study showed that the synthesised hydrogels were still effective in the removal of Pb, Cu and Cd in wastewater.