Preparation of highly effective bio-adsorbent from hemp fiber for removal of malachite green oxalate (MGO)

Water pollution caused by dyes continues to be the most current and vital problem of today. In this study, which aims to contribute to solving the aforementioned problem, hemp fiber (HF) which are eco-friendly, biodegradable, economical and easily available, was used as an adsorbent raw material to remove dyes from aqueous solution. Hemp fibers were modified with H2SO4 to improve its adsorptive properties and sulphated bio-adsorbent (SHF) was prepared. The prepared adsorbent was thoroughly characterized by using FTIR, SEM, EDX, BET, XRD, Boehm Titration techniques and calculating pHpzc. It is aimed to remove Malachite Green Oxalate (MGO) from wastewater. The effects of adsorbent amount, pH, initial dye concentration, contact time, temperature and ionic strength on adsorption were investigated in adsorption studies performed by batch method. Reusability study was carried out by performing desorption and adsorption processes with ten repetitions. It was observed that MGO adsorption onto SHF was fitted to the pseudo-second order kinetic and the Langmuir isotherm models. According to the Langmuir model, the adsorption capacity of MGO onto SHF is 1250.2, 1538.5, 1666.7 and 2000.8 mg/g at 298 K, 308 K, 318 K and 333 K, respectively. Thermodynamic parameters revealed that the adsorption process was endothermic and spontaneous. It was observed that it was almost unaffected by the ionic strength. It is seen that the decrease in percent dye removal efficiency after ten reuses is not significant. It was concluded that MGO from aqueous solution could be removed by the SHF with a very fast, high efficiency and capacity.