Adsorption Kinetics of Edamame Soybean Peel Activated Carbon in Reducing the Level of Phosphate

Domestic wastewater, such as detergent wastewater, causes the increase of the phosphate level that strongly contributes to eutrophication. Adsorption is a method that can be used to reduce the levels of phosphate. The natural ingredients that can be made as activated carbon include edamame soybean peel. because it contains a lot of cel-luloses. This research aimed to analyze the adsorption kinetics and adsorption capacity of edamame soybean peel activated carbon in reducing the phosphate levels. Adsorption was carried out with batch method with various concentrations of adsorbate (2 mg/L, 4 mg/L, and 6 mg/L) and stirring time (3 hours, 6 hours, 9 hours, and 12 hours). The results showed that the highest adsorption capacity was found in 6 mg/L of adsorbate concentration and 6 hours of stirring time. The results were validated by the Langmuir isotherm and pseudo-second-order adsorption kinetics model. The Langmuir isotherm indicated that adsorption occurred in monolayer. The maximum adsorption capacity was 0.43509 mg/g and the constant of adsorption kinetics was 1.5558 g/mg.min. Activated carbon from edamame soybean peel successfully reduced the levels of phosphate. The increase of adsorption capacity was correlated with the increasing concentration of adsorbate and stirring time until the equilibrium.

Automated summary

This study investigated the adsorption kinetics and capacity of activated carbon from edamame soybean peel in reducing phosphate levels. The results showed that the maximum adsorption capacity occurred at a 6 mg/L adsorbate concentration and 6 hours of stirring time. The Langmuir isotherm and pseudo-second-order adsorption kinetics model validated these results.