Optimization of lead (II) biosorption in an aqueous solution using chemically modified aerobic digested sludge

Abstract

Biosorption of Pb(II) by using digested sludge obtained from a municipal wastewater treatment plant in Tehran was examined. The aims of this investigation were biosorption of Pb(II) ions onto chemically treated digested sludge with hydrogen peroxide (H₂O₂) solution and determination of kinetic and isotherm of biosorption. Biosorption capacity of two types of sludge (treated and untreated) for biosorption of Pb(II) ions was investigated as function of initial Pb(II) concentration and pH using batch biosorption systems. The equilibrium biosorption capacity increased with increasing of initial metal ion concentrations and pH for both of digested sludge. The pseudo-second order kinetic model was found to be slightly suitable than the pseudo-first order kinetic model to correlate the experimental data for two types of digested sludge (R²>0.9). Regarding the applicability of the isotherm models, the freundlich model was found to be suitable than the other isotherm models. According to obtained q(max) from Langmuir isotherm, biosorption of Pb(II) by H₂O₂ treated digested sludge was found to perform better than untreated digested sludge. The maximum biosorption capacity was given 185.19 and 144.93 mgg⁻¹ for H₂O₂ treated and untreated digested sludge, respectively. Also, the constant of energy (B) between the Pb(II) ions and the adsorbent surface, calculated using BET isotherm model, obtained 5401 and 3401 for H₂O₂ treated and untreated digested sludge, respectively. These results indicate the usefulness of H₂O₂ treated digested sludge as a biosorbent for Pb(II) biosorption.

Kinetic and equilibrium adsorption of two post-harvest fungicides onto copper-exchanged montmorillonite: synergic and antagonistic effects of both fungicides’ presence

“…98.2 ± 0.1 92.5 ± 0.4 some cases where this value tends to zero, it would also be irreversible (Darvishi Cheshmeh Soltani et al 2011). In Fig.…”

Kinetic, isotherm, and thermodynamic studies for removal of direct red 12b using nanostructured biosilica incorporated into calcium alginate matrix

“…Figure a revealed that increasing temperature from 298 to 316 K led to decrease in the amount of adsorbed DR12B from 16.02 to 14.99 mg/g, respectively. Increasing temperature resulted in decreasing the adsorptive forces between the adsorbate molecules and surface of the adsorbent leading to the decrease in adsorption capacity . Obviously, decreasing temperature from 316 to 298 K resulted in no significant increase in the removal efficiency (%) of DR12B.…”

Application of Nanocrystalline Iranian Diatomite in Immobilized Form for Removal of a Textile Dye

“…where q e (mg/g), q t (mg/g) and k 1,ads (1/min) are the amount of adsorbed dye at equilibrium time, the amount of adsorbed dye at time t and the pseudo-first order reaction rate constant, respectively [34,37]. In addition, linearized form of the pseudo-second order kinetic model is shown through Eq.…”

“…conditions. Therefore, the adsorption of DR23 will be enhanced at acidic conditions [5,37]. In the presence of more silanol groups located on the surface of the adsorbent, hydrogen bonding is more common interaction between the adsorbent and adsorbate molecules [36].…”

“…where q m (mg/g), C e (mg/L) and K (L/mg) are the maximum monolayer adsorption capacity of the adsorbent,the residual dye concentration and the affinity of binding sites associated with the free energy of adsorption for removing adsorbate molecules, respectively [37]. Linearized form of the Freundlich isotherm model is represented via Eq.…”