Adsorption of phosphate from aqueous solutions using waste mussel shell

Excessive amount of phosphate released from wastewater can cause eutrophication to the receiving waters. Adsorption technique has been used to remove phosphate from aqueous solutions. The use of waste mussel shell (WMS) to remove phosphate from aqueous solutions and application of several kinetic and isotherm models to describe the adsorption of phosphate onto WMS were conducted in batch experiments. The phosphate adsorption by the WMS was examined with respect to solute concentration, contact time and adsorbent dose. The phosphate removal efficiencies obtained were 46.7, 57.6, 64.1, 70.8 and 75.2% at 144 h contact time for WMS dosage of 2, 4, 6, 8 and 10 g, respectively. Physical and chemical properties of WMS including surface physical morphology and elemental compositions were characterized. A comparison of kinetic models applied to the phosphate adsorption onto WMS was evaluated for the pseudo-first order and pseudo-second order model. The experimental data fitted very well with the pseudo-second order kinetic model (R2 > 0.984), which indicated the adsorption process was chemisorption. In the isotherm studies, the Langmuir and Freundlich isotherm models were applied. The results indicated that the use of Freundlich equation is well described with the phosphate adsorptions onto WMS (R2 = 0.968), suggesting the heterogeneity of the adsorbent surface. The experimental results suggested the use of WMS as an excellent adsorption material for phosphate removal from aqueous solutions, giving new insights into environmental engineering practices

Adsorption of phosphate from aqueous solutions using waste mussel shell

Excessive amount of phosphate released from wastewater can cause eutrophication to the receiving waters. Adsorption technique has been used to remove phosphate from aqueous solutions. The use of waste mussel shell (WMS) to remove phosphate from aqueous solutions and application of several kinetic and isotherm models to describe the adsorption of phosphate onto WMS were conducted in batch experiments. The phosphate adsorption by the WMS was examined with respect to solute concentration, contact time and adsorbent dose. The phosphate removal efficiencies obtained were 46.7, 57.6, 64.1, 70.8 and 75.2% at 144 h contact time for WMS dosage of 2, 4, 6, 8 and 10 g, respectively. Physical and chemical properties of WMS including surface physical morphology and elemental compositions were characterized. A comparison of kinetic models applied to the phosphate adsorption onto WMS was evaluated for the pseudo-first order and pseudo-second order model. The experimental data fitted very well with the pseudo-second order kinetic model (R2 > 0.984), which indicated the adsorption process was chemisorption. In the isotherm studies, the Langmuir and Freundlich isotherm models were applied. The results indicated that the use of Freundlich equation is well described with the phosphate adsorptions onto WMS (R2 = 0.968), suggesting the heterogeneity of the adsorbent surface. The experimental results suggested the use of WMS as an excellent adsorption material for phosphate removal from aqueous solutions, giving new insights into environmental engineering practices

Adsorption isotherms and kinetics of phosphate on waste mussel shell

In this study, removal of phosphate (PO43−) from aqueous solutions using waste mussel shell (WMS) was examined. The physicochemical characteristics of WMS were identified. In the batch experiments, the effects of contact time and adsorbent dosage (m) on the PO43− adsorption by the WMS were scrutinised. The maximum PO43− removal efficiency (E) was 83.4% at 144 h contact time for WMS dosage of 10 g. A comparison of kinetic models applied to the adsorption of PO43− onto WMS was evaluated using pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The experimental data was fitted well with the PSO kinetic model. In the isotherm studies, Langmuir and Freundlich isotherm models were applied. The Langmuir isotherm model was well described with the PO43− adsorption. The results indicated that WMS has a good potential to adsorb PO43− from water and thus could improve environmental quality. Furthermore, this study investigated on how the Langmuir isotherm for basic adsorption could be applied to predict E or required m under a given set of initial conditions (i.e., initial solute concentration, solution volume, and adsorbent dosage). This was accomplished by combining the Langmuir isotherm with mass balance of solutes between liquid solution and solid adsorbent phases