Water Pollution and Treatment Technologies

Kinetics, Thermodynamics, and Isotherms of Methylene Blue Adsorption Study onto Cassava Stem Activated Carbon

“…The multilayer adsorption characteristic onto the heterogeneous surface with irregular distribution of adsorption energy is described by the Freundlich isotherm model [53]. It was expressed in linear form as ln qe = ln Kf + 1 n ln Ce, where, qe is the adsorption capacity adsorbed at equilibrium (mg/g), Ce is the equilibrium concentration of adsorbate (mg/L), Kf is the Freundlich isotherm constant, and 1 n is the adsorption intensity that varies with the heterogeneity of the adsorbent. The constants n and Kf are determined from the slope and intercept of the graph of ln qe versus ln Ce, as shown in Figure 7.…”

“…The partition between the two phases is independent of the concentration if = 1. Normal adsorption, which corresponds to the normal L-type Langmuir isotherm, is specified once values of < 1, and cooperatives adsorption that involve strong interaction between the molecules of adsorbate is specified The nature and strength of the sorption process, as well as the distribution of the active sites, is measured from the slopes 1 n . The partition between the two phases is independent of the concentration if 1 n = 1.…”

“…The partition between the two phases is independent of the concentration if 1 n = 1. Normal adsorption, which corresponds to the normal L-type Langmuir isotherm, is specified once values of 1 n < 1, and cooperatives adsorption that involve strong interaction between the molecules of adsorbate is specified when the value 1 n > 1. The value of 1 n for all types of adsorbent samples in this study presented a value of less than 1.…”

“…Normal adsorption, which corresponds to the normal L-type Langmuir isotherm, is specified once values of 1 n < 1, and cooperatives adsorption that involve strong interaction between the molecules of adsorbate is specified when the value 1 n > 1. The value of 1 n for all types of adsorbent samples in this study presented a value of less than 1. This revealed that the adsorption of the MB onto the surface of cassava stem adsorbents is normal in equivalents to the normal L-type of the Langmuir isotherm [52].…”

“…These techniques include reverse osmosis, ion exchange, dialysis or electrodialysis, cementation, electrolyte extraction, oxidationreduction, solvent extraction, evaporation, adsorption, dilution, filtration, and chemical precipitation. Among these techniques, adsorption has been widely practice [1]. Due to several advantages, such as low initial cost, non-complex design, less sensitivity to toxic substances, and ease of operation, the adsorption process was commonly adopted, considering its versatility and high cleaning effectiveness [2].…”