Abstract:
This study aims to determine the efficiency and biosorption capacity of biosorbents in
adsorbing mercury(II), determine the kinetics model and biosorption isotherms and the
ability to regenerate biosorbent in white jabon fruit. Optimization of the biosorbent
powder was carried out on the parameters of pH, contact time and adsorbate
concentration. The biosorbent is then regenerated by desorption using HCl solution. The
results of the physical and chemical characterization in this study showed a moisture
content of 8.09%, ash content of 1.32%, adsorption capacity of iodine 753.5812 mg/g
and adsorption capacity of methylene blue 24.8632 mg/g with a surface area of 92.1764
m2/g. Results The pHpzc value for the Jabon fruit biosorbent powder was 5.5 which
indicated that the biosorbent powder had a negative charge. The results of the
biosorption test showed that the optimum condition of the biosorbent powder was at a
variation of pH 6, contact time and at an initial concentration of 80 mg/L with a
biosorption efficiency of 99.91% and a biosorption capacity of 3.5761 mg/g. Based on
the FTIR results of aliphatic C-H functional groups, aromatic C-H, C=O, C-O-C, O-Hg
and N-H. Based on the results of the BET analysis, the biosorbent powder had a surface
area before biosorption of 3.53039 m2/g, after biosorption of 0 m2/g and after resorption
of 0.17056 m2/g. Based on the results of the SEM-EDS, it was found that the jabon fruit
biosorbent powder had the elements O, C, Na, N, Cl, K, Hg and had an uneven texture
and the distance between the particles looked very tight and had a small grain size. The
surface texture looks very smooth. In this study, the percentage of regeneration was
98.34%. Biosorption kinetics follows the second-order pseudo-equation where the
equation is y = 0.2097x – 0.0075 with R2 = 1 and K = 5.86339 gmg-1min-1, assuming a
chemical adsorption process that includes inter-valence forces or electron exchange
between the adsorbent and the adsorbate and the biosorption isotherm model follows the
Langmuir equation with the equation y = 0.019x + 0.0153 with R2 = 0.9665, it is
assumed that the active site on the surface of the adsorbent is homogeneous.
