The application of waste Leucaena leucocephala seed pods as a bio-based adsorbent for decolourization of solution

Abstract

The adsorption method is widely used in water and wastewater treatment; however, most industrial adsorbents are expensive, limiting the use of the adsorption method in developing countries. Therefore, this study aims at developing a biosorbent from waste Leucaena leucocephala seed pods (LLSP) and apply it (as a cost-effective bio-adsorbent) to remove Janus Green B dye (JGBD) from solutions at different values of pH, agitation time, LLSP dose and JGBD concentration. Different techniques were used to characterize LLSP before and after JGBD removal, including pore size distribution, surface area (SBET) analysis, FTIR, SEM, SPM and the point of zero charges (pHpzc) of the LLSP surface. The results proved that LLSP could remove up to 95% of JGBD at pH, LLSP dose, JGBD concentration and agitation time of 9, 0.08 g/100 ml, 50 mg/l and 30 min, respectively. Langmuir and Freundlich analyses were applied to fit the data for equilibrium biosorption, and it was noticed that the Langmuir isotherm model fits the data, and the full monolayer biosorption ability for JGBD was 142.85 mg/g.