Chemical Engineering
A. Alipour; S. Zarrinabadi; A. Azimi; M. Mirzaei
Abstract
Cellulose nanocomposites were synthesized and applied to the removal of Pb(II) from aqueous solution. The synthesized nanocomposite was characterized by FT-IR, XRD, SEM, TEM, and BET analyses. Removal experiments were carried out in laboratory scale and then evaluated by response surface methodology ...
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Cellulose nanocomposites were synthesized and applied to the removal of Pb(II) from aqueous solution. The synthesized nanocomposite was characterized by FT-IR, XRD, SEM, TEM, and BET analyses. Removal experiments were carried out in laboratory scale and then evaluated by response surface methodology (RSM) with a Central-Composite Design. The effects of solution pH, contact tie, initial Pb(II) concentration, adsorbent dosage and temperature on the removal efficiency were evaluated. Analysis of variance (ANOVA) was employed to find which parameter has a significant effect on the removal efficiency. The best removal efficiency value was found to be at the initial solution pH of 6.5, temperature of 34°C, initial ion concentration of 100 mg/L and the adsorbent dosage of 0.74 g/L. At this condition, the removal efficiency of Pb(II) ions was 92.54%. The adsorption equilibrium data fitted well with Langmuir isotherm model and the adsorption process followed the pseudo-second-order and intra-particle diffusion kinetic model. Thermodynamic analysis suggests that the adsorption process is endothermic, with an increasing entropy and spontaneous in nature. Besides, the nanocomposite was reused in four successive adsorption–desorption cycles, revealing a good regeneration capacity of the adsorbent. The effects of coexist cation ions on the adsorption of Pb(II) under optimal condition was also investigated. All the results demonstrate that nanocomposite is a potential recyclable adsorbent for hazardous metal ions in wastewater system.
H. Ahmad; N. I. Abd Ghalib; F. M. Shamshudin; N. Ismail
Abstract
Leachate contents from the landfill that infiltrate the liner may contaminate nearby groundwater and river. Hence, the liner material must be chosen properly so that pollutants can be retained as much as possible at the liner thus reducing the contamination risk. This study studied the characteristics ...
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Leachate contents from the landfill that infiltrate the liner may contaminate nearby groundwater and river. Hence, the liner material must be chosen properly so that pollutants can be retained as much as possible at the liner thus reducing the contamination risk. This study studied the characteristics of earthenware clay and pressmud, and their suitability in reducing heavy metals content in leachate. Their suitability to fit as candidate for a landfill liner was tested using batch equilibrium study at 24 and 48 hours reaction times. The mixture of clay and pressmud were labelled PM0, PM10, PM30, PM50, PM80 and PM100 based on their pressmud content. Both reaction time, in any mixtures, manganese easily removed from leachate. 97% zinc was reduced in PM80 after 48 hours reaction time. No significant removal detected for lead in PM0, PM50 and PM80 although the experiment was prolonged from 24 to 48 hours. In a nutshell, for overall contaminants, the longer the reaction time, the higher removal percentage. The clay-pressmud mixtures have the potential to be applied as a landfill liner, however, the removal percentage of metal ions depends on mixture’s physicochemical characteristic.
