Application of Azolla for 2, 4, 6-Trichlorophenol (TCP) Removal from Aqueous Solutions

Background & Aims of the Study: The 2, 4, 6-Trichlorophenol (TCP) is a phenolic compound which it can produce adverse effects on human and environment. Therefore, the removal of these compounds is necessary. The aim of this study is the investigation of TCP removal by using Azolla filiculoides biomass. Materials & Methods: The Azolla biomass was dried in the sunlight, and then it was crushed and sieved to particle sizes in range of 1-2 mm. Next treated with 0.1M HCl for a period of 5h. The Azolla was washed with distilled water and it was used as adsorbent. The effect of operating parameters such as pH, contact time, TCP concentration and adsorbent dose on the TCP removal efficiency was investigated. The residues concentration of TCP was measured by spectrophotometer in λ max of 296 nm. Results: In optimum condition (pH 3, contact time 120 min , adsorbent dose 10 gr/l and TCP concentration 10 ppm), Azolla was able to remove 95% of TCP from aqueous solutions. The equilibrium data follows the Langmuir isotherm and the proper kinetic model is pseudo-second model. Conclusions: Adsorption process by Azolla filiculoides is an efficient method for removal of 2, 4, 6-Trichlorophenol from aqueous solutions.