| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4416670 | Chemosphere | 2006 | 11 Pages |
The presence of citric acid in decontamination waste can cause complexation of the radioactive cations resulting in interferences in their removal by various treatment processes such as chemical precipitation, ion-exchange, etc., which are employed for the removal of radioactivity and may cause potential danger to the environment. Mesoporous Al-MCM-41 (Si/Al = 30, 51, 72 and 97) and Si-MCM-41 molecular sieves were synthesized hydrothermally and characterized by XRD, BET (surface area) and FT-IR to evaluate the removal of citric acid through an adsorption process. Adsorption of citric acid over Al-MCM-41 shows the applicability of Freundlich and Langmuir isotherm and follows first order kinetics. The effects of contact time, concentration of citric acid, adsorbents (various Si/Al ratios of Al-MCM-41, Si-MCM-41, Hβ zeolite and commercial carbon) and pH have been investigated. It has been found that the amount of citric acid adsorbed per unit gram of catalyst followed the order Al-MCM-41 (Si/Al = 30) > Al-MCM-41 (Si/Al = 51) > activated charcoal > Al-MCM-41 (Si/Al = 72) > Al-MCM-41 (Si/Al = 97) > Si-MCM-41 > Hβ zeolite.
