STUDIES ON THE ADSORPTION OF HEAVY METAL IONS AND DYE FROM AQUEOUS SOLUTION USING PHYSIC SEED HULL (Jatropha curcas L.)

• Main Author: MOHAMMAD, MASITA
• Format: Thesis
• Language: English; English; English
• Published: 2010
• Online Access: http://utpedia.utp.edu.my/2795/1/1.Coverpage-Thesis_final_2.pdf; http://utpedia.utp.edu.my/2795/2/2.Front_Page-Thesis_final_2.pdf; http://utpedia.utp.edu.my/2795/3/3-6_thesis_final_2.pdf; http://utpedia.utp.edu.my/2795/

In this work, the adsorption potential of physic seed hull (PSH), Jantropha curcas L. as an adsorbent for the removal of metal ions (Zn2+ and Cd2+) and malachite green dye (MG) from aqueous solution has been investigated. The study also has been extended to investigate the effect of anionic surfactant (tetra sodium N-(1, 2dicarboxy ethyl)-Noctadecyl sulfosuccinamate), known as Aerosol 22, on these adsorption processes. The performance of the adsorbent PSH has also been compared with granular activated carbon (GAC) adsorbent. The adsorbent, PSH was thoroughly characterized by SEM-EDX, BET, CHNS, Zeta potential measurement and FTIR studies. It has been observed that the adsorption of metal ions and dye increased with the increase in initial metal ions/dye concentration, contact time of adsorbent and adsorbate, temperature of adsorption, dosage of adsorbent and pH of the solution in an acidic range, but decreased with the increase in the particle size of PSH. Both PSH and GAC adsorbent exhibited better adsorption ability towards Zn2+ than Cd2+ from aqueous solution. But the adsorption capacity of PSH was found to the higher than that of GAC for both the metal ions and MG dye. Aerosol 22 was used during the adsorption process to provide the anionic functional group on the surface of PSH for supplying further adsorption site for metal ions. Addition of Aerosol 22 improved the adsorbing capacity of PSH for both the metal ions, but the effect was observed to be more for Zn2+. Again, it was further observed that at higher concentration of the surfactant there was a decrease in the adsorption of metal ions. It might be related to the formation of micelles that prevented the adsorption of metal ions. The adsorption process for both the metal ions and dye on PSH was found to be consists of three-staged process - a rapid initial adsorption of the metal ions initially, followed by a period of slower uptake of the metal ions and finally no significant uptake of the metal ions. The kinetics of metal ions adsorption process was therefore described by a pseudo-second order model. The adsorption equilibrium data were fitted in the three adsorption isotherms, e.g. Freundlich isotherm, Langmuir isotherm and Dubinin-Radushkevich isotherm. The adsorption data fitted best to the Langmuir isotherm indicating the adsorption of metal ions and dye on PSH could be described as a monolayer chemisorption proces. The activating energy for the adsorption of metal ions and dye as calculated using from D-R Isotherm was found to be more than 16kJ/mol which is particle diffusion. The adsorption capacity of PSH was found to be comparable to that for other available adsorbents as cited in literatures. From the study it is evident that as an adsorbent, PSH has significant potential for usage in the separation of metal ions and dye from waste water.