In this study, an industrial waste-blast furnace slag (BFS) supported sulfidized nanoscale zerovalent iron (S-nZVI@BFS) was prepared and used for synergistic reduction and adsorptive removal of Cr(VI) from aqueous solutions. The characterization analysis showed that Fe 0 and FeS were well dispersed on the surface of BFS, and the specific surface area of S-nZVI@BFS was 141.986 m 2 g −1 . Batch experiments demonstrated that the removal capacity of Cr(VI) was as high as 184 mg/g for S-nZVI@BFS. The pseudo-second-order kinetic model fitted the Cr(VI) removal kinetics well. Cr(VI) removal on the S-nZVI@BFS relied highly on pH values. The reduced Cr(VI) precipitated on S-nZVI@BFS mainly as Cr x Fe (1-x) (OH) 3 , Cr x Fe (1-x) OOH and Cr 2 S 3 , and the alkaline capacity of the BFS could efficiently prevent the release of Cr(III) from the precipitations in acid condition. Thus, supporting S-nZVI on BFS was an effective and safe method for Cr(VI) removal from aqueous solutions.
Chen Mao,Dong Xiaosen,Pu Shuiqiang,Tang Wenbo,Zheng Kui
Na 2 O and K 2 O alkaline oxide capacities of TiO 2 -bearing blast furnace slags are critical values for vanadium titanomagnetite blast furnace operation. In this study, high-temperature experiments with fast-quenching were conducted to investigate the effects of TiO 2 concentration, basicity, MgO and Al 2 O 3 concentrations on Na 2 O and K 2 O concentrations in the TiO 2 -bearing blast furnace slags. The results were correlated with optical basicity and also compared with the plant data from one commercial vanadium titanomagnetite blast furnace.
Since the yield of titanium-bearing blast furnace slag (TF) during the smelting of vanadium titanium magnetite is large, it is urgent to find ways to recycle it and implement its value-added utilization. In this study, a perovskite-rich photocatalyst was prepared by acid-washing of TF, and then Ce was doped to modify it for photocatalytic removal of gaseous toluene under the irradiation of visible light. XRD, XRF and XPS analyses demonstrated that the perovskite phase was enriched after the acid-washing, and the content of CaTiO 3 in the acid-washed slag (AS) also increased after Ce doping. The combined N 2 adsorption-desorption, UV Vis DRS, EIS, PL , and ESR analysis results indicated that the photocatalytic performance of the mentioned photocatalyst was related to the Ce dopant content. The AS doped with 20% Ce (20% Ce-AS) had a lower band gap and larger specific surface area than the others catalysts. Under visible light radiation , more active radicals were produced, and the removal efficiency of toluene reached 92.08% for 20% Ce-AS. In addition, the results of the in situ DRIFTS tests indicated that toluene was gradually degraded by the Ce-doped perovskite-type photocatalyst to alcohols and aldehydes and mineralized to H 2 O and CO 2 . This study is expected to provide a new approach for the technical development of the value-added utilization of TF coupled with the efficient removal of toluene.
The low-cost of CO 2 adsorbent is crucial for realistic CO 2 adsorption application. In this paper, a series of green CO 2 adsorbents were prepared using tetraethylenepentamine (TEPA) functionalized blast furnace slag (BFS) as raw materials, which not only implemented the recycling of blast furnace slag solid waste, but also realized the low cost of amine adsorbents. A series of characterization analyses were performed on the synthesized hydrotalcite-like and hydrated calcium silicate green support materials. The effects of structures, TEPA loadings and adsorption temperatures on the material properties were investigated. The result shows that BFS10.5-50TEPA with more pores is an ideal adsorbent, its optimum adsorption capacity for CO 2 is 5.64 mmol/g at 80 ℃, and the amine efficiency is as high as 38.42 %. According to CO 2 -TPD analysis, the dominant CO 2 adsorption mechanism of BFS10.5-50TEPA were physisorption and weak chemisorption. Moreover, the adsorption kinetics and regeneration performances also studied. The results indicate that pseudo-first-order model and pseudo-second-order model are both not accurately at predicting experimental results, while the Avrami model can accurately predict the adsorption kinetics of CO 2 at both low adsorption temperature and high adsorption temperature. After 10 adsorption-desorption recycles, the CO 2 adsorption capacity of BFS10.5-50TEPA still maintain 5.02 mmol/g. This study provides a novel method for the preparation of solid amine adsorbents with high adsorption performance from low-cost solid waste.
危险品化学品经营许可证（带存储）