Adsorption of Molybdenum Ion in Nitric Acid Solution by Using a Pb-Fe Based Adsorbent

Abstract

Experimental Synthesis of the Pb-Fe based AdsorbentsEach Pb-Fe based adsorbents was precipitated (at 25℃) by adding sodium hydroxide (NaOH) in a mixture of 1 mol/L lead nitrate Pb(NO 3 ) 2 and 1 mol/L ferric nitrate (Fe(NO 3 ) 3 . 9 H 2 O) aqueous solutions, until pH of the mixture was adjusted to a desired value. The suspensions were then filtered and the precipitates were dried at 70℃ for over 72 hrs. Finally, each precipitate was ground by using an agate mortar with pestle to obtain a fine powder, which has been used as an adsorbent. In same cases, prior to the adsorption experiment, the prepared powder was also calcinated at a temperature between 100 and 800℃.The synthesized adsorbents were characterized by means of a thermogravimetric analyzer (TG/DTA: Shimadzu DTG-50), a X-ray diffractometer (XRD: Mac Science, MO3XHF), and a scanning electron microscope (SEM: Keyence, VE-8800). -mail: dodbiba@geosys.t.u-tokyo.ac.jp In order to remove molybdenum (Mo) from the high-level radioactive liquid waste (HLLW), Pb-Fe based adsorbents were synthesized and their adsorption capacities were investigated. The adsorbent precursors were prepared with precipitation at various pH values by adding sodium hydroxide into a mixture of 1 mol/L lead nitrate and 1 mol/L ferric nitrate aqueous solutions, and each precipitate was then filtered, dried and ground to obtain a fine powder precursor. The precursors were also calcinated at various temperatures to obtain the Pb-Fe based adsorbents. Adsorption of Molybdenum Ion in Nitric AcidETwo main parameters were considered when synthesizing the adsorbents, i.e. the pH value of precipitation of adsorbent precursor as well as the calcination temperature of the Pb-Fe based adsorbent. The experimental results indicated that the calcination temperature has a great influence on adsorption capacity of the Pb-Fe based adsorbent for Mo. It was found that when the precursor was precipitated at pH 9 and then calcinated at 500℃, the sorbed amount of Mo by the adsorbent was the highest. In addition, the equilibrium sorption isotherm of Mo onto the adsorbent was estimated by the Langmuir, Freundlich and Redlich-Peterson sorption models. We found that the overall adsorption process was described well by Redlich-Peterson sorption isotherm equation.

Pollutant Removal from Synthetic Aqueous Solutions with a Combined Electrochemical Oxidation and Adsorption Method

“…Similar values for R 2 have been reported for ammonia by zeolite, activated carbon, and composite adsorbent [ 14 ]. Moreover, similar R 2 values have been reported for phenol adsorption using granular activated carbon and Mo adsorption while using Pb–Fe-based adsorbent [ 47 ].…”

Molybdenum(VI) removal from aqueous solutions using bentonite and powdered cockle shell; Optimization by response surface methodology

“…The same R 2 values were reported by Dodbiba et al (2010) regarding Mo adsorption by Pb-Fe-based adsorbents. A dimensionless equilibrium parameter separation factor (RL) could be used to express the characteristics of the Langmuir isotherm (Isa et al, 2007).…”

Liquid Radioactive Wastes Treatment: A Review

“…The effluent stream from the ion exchange treatment process had significant activity due to 106 Ru. A study was directed to investigate the possibility of using cobalt and nickel sulfides for the removal of 106 Ru [36].…”