A Study on the Adsorption of Molybdenum (VI) by Synthesized Ferrite

• Main Authors: Hong,Wan-Jhen, 洪婉禎
• Other Authors: Chang,Chien-Kuei
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/59216119082103857564

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 101 === The photoelectric industry is one of the important industries in Taiwan. However, the environmental issues were neglected in development process. In Taiwan, the effluent of gallium (Ga), indium (In), molybdenum (Mo), total toxic organics (TTO), and acute organism toxicity (TUa) in photoelectric material industry was regulated by the Environmental Protection Administration since 2012. The traditional methods for Mo removal such as ion exchange and coagulation precipitation receive serious challenge due to the interference of anions especially phosphate. The sludge generated from ferrite process in this study was used as an adsorbent and investigated its performance for removal of Mo from wastewater (Mo was limited by 0.6 mg/L in effluent). Additionally, by taking the advantage of paramagnetism, the ferrite, after adsorption, could be separated rapidly by using the extra magnetic field. The adsorption isotherm data showed that under the condition of initial Mo concentration 30 mg/L, pH 3, and temperature 25℃, the adsorption capacity of the nickel ferrite (M/Fe=1/5) and copper ferrite (M/Fe=1/2) could be found as 11.83, and 11.99 mg/g, respectively. Moreover, the residual concentration is lower than the regulated limit 0.6 mg/L. The Mo adsorption behavior onto ferrite could be fitted to the Langmuir isotherm and the adsorption capacity in acidic condition was more than that in alkaline condition. Desorption results indicate that high Mo desorption was occurred when the pH is higher than the pHzpc of ferrite due to the positive charged on the surface of adsorbents. Additionally, the adsorbents were successfully regenerated with 1M NaOH. After five cycles of adsorption-desorption process, Mo removal efficiency could still reach 98%, demonstrating that the potential of reusability of synthesized ferrite adsorbents.