Preparation of Mesoporous Carbon from Sodium Lignosulfonate by Hydrothermal and Template Method and Its Adsorption of Uranium(VI)

Abstract

A novel adsorbent of mesoporous carbon with high specific surface area was successfully prepared by hydrothermal and template method, using sodium lignosulfonate (LSs) as a raw material and cetyltrimethylammonium bromide (CTAB) as a template agent. The mesoporous carbon was characterized by SEM, TEM, BET, FTIR, and XPS. The formation mechanism of the mesoporous carbon was analyzed. The adsorption of uranium(VI) on the mesoporous carbon from the simulated aqueous solution and actual radioactive wastewater was respectively investigated. The optimum conditions for U(VI) adsorption were determined by studying experimental variables including pH, contact time, sorbent dose, initial concentration, and temperature. The results indicated that the maximum adsorption capacity of the mesoporous carbon for U(VI) in the simulated aqueous solution and actual radioactive wastewater was respectively 109.46 mg/g at pH 5.5 and 328.15 K and 195.6 mg/g at pH 5.5 and the initial U(VI) concentration of 189.75 mg/L. The adsorption data could be well described by the pseudo-second-order model and Freundlich isotherm model. The adsorption of U(VI) on the mesoporous carbon was an endothermic and spontaneous process. The adsorption mechanism may be a complex chemical reaction between uranium and the oxygen-containing functional groups on the mesoporous carbon.

Thiol–Ene Synthesis of Cysteine-Functionalized Lignin for the Enhanced Adsorption of Cu(II) and Pb(II)

“…Moreover, the comparison of fitted coefficients ( R 2 ) from two models indicated that the adsorption kinetics could be better described by pseudo-second-order model (0.9993 and 0.9998) than that of pseudo-first-order model (0.8044 and 0.7253). Based on the assumption of pseudo-second-order model, the adsorption mechanism was chemisorption process between CFL and metal ions …”

“…Based on the assumption of pseudo-second-order model, the adsorption mechanism was chemisorption process between CFL and metal ions. 32 To evaluate the adsorption capacity, the adsorption isotherms were examined with various concentrations in the range of 25−500 mg/L of metal ions at 15 °C. In Figure 2d, the adsorption capacities of Cu(II) and Pb(II) by CFL increased with increases in metal ion concentrations and finally leveled off at 68.7 and 55.5 mg/g, respectively.…”

Mild hydrothermally treated brewer's spent grain for efficient removal of uranyl and rare earth metal ions

“…57 These hydrated species are more easily adsorbed due to their high affinity for solid surfaces. 58 Kinetic study. The results of adsorption experiments in dependent of the contact time for BSG and ABSG are depicted in Fig.…”

Recycling of Brewer’s Spent Grain as a Biosorbent by Nitro-Oxidation for Uranyl Ion Removal from Wastewater

“…In particular, uranium presents renal, developmental, and reproductive toxicity and causes diminished bone growth and DNA damage, as obtained from experimental animal studies and human epidemiology. 5 Numerous adsorbents have been explored to remove uranium from the water environment, such as mesoporous carbon, 6 graphene oxides, 7 hydrochar, 8 chitosan, 9 amidoxime-based materials, 10 and functional fibrous material-based adsorbents. 11 Natural organic raw materials are the most attractive materials for green adsorbent production, and the diversity of raw materials of biosorbents has been increased rapidly, including hazelnut shells, 12 chitosan, 13 nanocellulose, 14 starch, 15 saw dust, 16 etc.…”

“…where k F ((mg/g) (L/mg) 1/n ) is the Freundlich isotherm constant related to adsorption capacity and n is the Freundlich isotherm constant related to adsorption intensity (6) where k R (L/g) and a R (L β /mg β ) are the Redlich−Peterson isotherm constants and β is the Redlich−Peterson isotherm exponent. The fitting results and isotherm parameters are summarized in Table 2, and the detailed statistical evaluations are given in Table S8.…”