Two types of Shrimp Chitin derivatives and two types of Iranian natural Zeolite derivatives (Firuzkooh Clinoptiliolite) were studied for adsorption and treatment of low-level radioactive liquid waste (LLW). Chitin with lowers than 10% and Chtiosan with higher than 90% deacetylation factor were selected as natural organic adsorbents. Natural Cliniptilolite of Firuzkooh area and Na form derivatives of it were selected as natural inorganic adsorbents. The static and dynamic ion exchange experimental results show that the adadsorption efficiency depend on particle size, PH, adsorbent type, deacetylation factor (in Chitin adsorbents) and cation type. The best Cs adsorption occurred in Na form Clinoptilolite. Nevertheless Chitin derivatives, particularly Chitosan, are more efficient than Zeolite adsorbents for removing of radionuclides such as 137 Cs, 54 Mn, 90 Sr and 60 Co. Adsorption performance was discussed and compared with each other.

In this research, a TiO 2 -activated carbon nano-composite was prepared by a sol-gel method and characterized by XRD, FE-SEM, EDS, FTIR, BET surface area, photoluminescence spectroscopy and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activity of the nano-composite was evaluated through degradation of reactive red 198 (RR 198) under UV light, and was compared to unsupported TiO 2 . The XRD result indicated that the TiO 2 nano-composite contained only anatase phase. The surface area of the TiO 2 increased from 48 to 100 m 2 /g through the fabrication of the nano-composite. The photocatalytic results indicated that the RR 198 was decolorized around 42 and 38 % during a 210-min irradiation period in the presence of nano-composite and TiO 2 , respectively. It means that nano-composite enhanced the photocatalytic activity of the TiO 2 nanoparticles. After 20 h of irradiation in the presence of the nano-composite, 97 % of RR 198 had degraded.