Role of Ricinus communis Plants: As Highly Adsorbent Surface for Removal of Dyes from Aqueous Solutions and Its Role of Biological Activity

Abstract

In this study, leaves from perennial plants, Ricinus communis, RC was used. It’s a natural form without any chemical treatments. The obtained powders are characterised by utilising several methods like (UV–Vis) Spectroscopy, EFSEM, TEM, FTIR, and XRD. The adsorption system is one of the most significant ways to eliminate contaminants such as brilliant blue and BB dye from aqueous solutions, depending on several factors that can be affected by the adsorption process, like contact time, where the best equilibrium time was after 1 hr. The effect of the adsorbent dosage from 0.025 g/100 mL to 0.12 g/100 mL that was found when weight increased removal percentage increased from 63.34% to 96.54% respectively. On the contrary, the adsorption efficiency decreased from 95.12 mg/g to 40.56 mg/g, the effect concentration of BB dye from 10 mg/L to 100 mg/L was found with an increased concentration of BB dye, the adsorption capacity increased from 10.23 mg/g to 62.56 mg/g, respectively, the effect of pH of solution (3.00-10.00) and the best adsorption efficiency found at pH = 6.00. A comparison was also made between natural Ricinus communis, RC and natural fruits Ricinus communis, FRC, activated untreated-acid Ricinus communis Pericarp, ARC and acidic-treated Ricinus communis pericarp, ACRC. Also, adsorption isotherms were studied for both Langmuir and Freundlich models, It was found that results followed Freundlich isotherm by depending on the value of (r² = 0.9559) and also on heterogeneous surfaces. The thermodynamic parameters studies find the sorption BB dye was negative by the value of Gibbs free energy which means the process is (spontaneous), While enthalpy changes are positive (endothermic). The values of the positive of ΔS are not very large and agree with the decrease in the degree of freedom. The performance and reuse of RC by using 0.01 N HCl in the adsorption process of dyes were investigated up to 6 cycle under best conditions. Results showed that the surface of RC has biological activity against the Gram-negative bacteria compared to the Gram-positive bacteria with an inhibition area (20 mm).