Application of Low-Cost Adsorption Technique on Organic Pollutant Dye Removal by Bio-Waste Adsorbents

This study focused on studying the kinetics, thermodynamics, and the adsorption equilibrium of Acid fuchsin, C.I acid violet 19 (AV19) dye from aqueous media by using different adsorbent such as Caw Animal Bone (CAB) and Hen Eggshell (HES) as a new cheap, low- cost, widely available, eco-friendly, high-efficiency adsorbents. Scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR) techniques were used to characterize the adsorbent before and after adsorption process. The influence of different conditions had been examined such as pH solution, initial dye concentrations, adsorbent dose, adsorbent sizes, contact time and different temperatures. The equilibrium data was analyzed by Langmuir and Freundlich's isotherm models and showed a good fit with the Langmuir model more than Freundlich's isotherm model (R2= 0.997), and a pseudo-second order kinetic is the best model suggested to explain the kinetics model with a good agreement with the intra-particle diffusion model. The parameters of thermodynamic including enthalpy.H degrees, entropy.S degrees and free energy.G degrees demonstrated that the adsorption process was feasible, spontaneous, and endothermic in nature of the adsorption of AV19 on CAB and exothermic nature of adsorption of AV19 on HES. The results clarified that a large percentage removal and the optimized conditions were (4 +/- 0.2 and 2 +/- 0.2) solution pH, 3.82mg/L initial dye concentration, adsorbent dose 0.75 gm/40 ml of particle size (2.36 and 0.355), for CAB and HES respectively and 60 min adsorption time 81.2% and 91.4% of dye was removed by CAB and HES respectively at experimental optimum conditions. The experimental results show that CAB and HES have a good potential as adsorbent to remove the colour from textile effluent and as an alternate low-cost adsorbent.