Isotherm and Kinetic Study of Phosphor Adsorption from Aqueous Solution using Single Wall Carbon Nanotubes

The presence of trace amounts of phosphorus in treated wastewaters from municipalities and industries results in eutrophication.Therefore, its removal is crucial for controlling eutrophication in receiving water. Hence, the aim of this study was to evaluate the phosphor adsorption from aqueous solution using single wall carbon nanotubes (SWCNT) as a sorbent. The batch experiments were performed at laboratory scale. The SWCNT was characterized using scanning electron microscope (SEM). The effects of operational parameters such as adsorbent dosage, pH, and initial phosphor concentration on initial phosphor removal were evaluated. The isotherm and kinetics of phosphor adsorption were determined. The results showed that phosphor removal was directly proportional with increase in adsorbent dosage and it was reversely proportional with increase in initial phosphorous concentration. Therefore, with adsorbent dosage increased from 0.1 to 0.4 mg/l, the percentage of removal increased from 83.0 to 92.5%. Moreover, the pseudo-first order, pseudo-second order kinetic, and intraparticle diffusion models were used to describe the kinetic data. The experimental data fitted well with pseudo-second order kinetic model. Equilibrium isotherms were analyzed by Langmuir, Freundlich, and Tempkin adsorption models. It was found that the adsorption isotherm was correlated reasonably well with Freundlich isotherm. The high adsorption capacity of SWCNT indicates that this adsorbent might be a suitable alternative to remove pollutants from aqueous media. It is concluded that the SWCNTs have a high potential for phosphor adsorption and can be used as an effective adsorption for removal of phosphor form effluents.