Removal of Reactive Black-5 Dye by Adsorption Using Rhamnus pits as Agriculture Waste for Environmental Sustainability

Abstract

The ability of reuse the agriculture waste to absorb Reactive Black 5 (RB5) dye from textile waste water is being investigated in this study. Rhamnus pits (RP) was used as an available waste material as an adsorbent by inciting and impregnating it with a strong base (KOH) and a strong acid (HCL) to produce a substance with high adsorption efficiency. The impregnation process was carried out in stages. First, the RP stones was incited at a temperature of 300 °C by the carbonization process, and then a part of the sample was impregnated with hydrochloric acid HCL (a strong acid) and a sample with sodium hydroxide KOH (a strong base), and then it was incited by the activation process by inciting it at a temperature of 600 °C. There were three types of adsorbents: one without impregnation, one impregnated with a strong acid, and one impregnated with a strong base. These samples were used for dye adsorption (RB5). Several factors and their impact on the adsorption procedure were investigated and utilized to calculate the adsorption capacity and the highest adsorption rate. It declared that the best removal percentage was achieved when impregnated with KOH (94.22%) and HCL (86.42%), while the free sample without impregnation had a 58% removal efficiency. The adsorption process was done at a temperature of 30 °C (86 °F), dose 0.05 g/10 ml of dye solution, time of 60 minutes, and 25 mg/l concentration of dye solution. Two standard adsorption isotherm models were used to determine the equilibrium adsorption curves. The Langmuir isotherm model provided a decent match to the data for RP pits activated with KOH. Adsorption kinetics were investigated using two different kinetic models: pseudo-second order and pseudo-first order. It was shown that the adsorption rate increases dramatically at first and then decreases to reach equilibrium. The data were showed good match by the model of the pseudo-second order with a confidence level of 0.9997.