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Leaching behavior of vanadium from spent SCR catalyst and its immobilization in cement-based solidification/stabilization with sulfurizing agent.
- Source :
-
Fuel . May2019, Vol. 243, p406-412. 7p. - Publication Year :
- 2019
-
Abstract
- Abstract To understand the potential leaching toxicity of V in spent SCR catalysts for human and environment, the leaching behavior of V in spent V 2 O 5 -WO 3 /TiO 2 SCR catalysts before and after cement stabilization/solidification (S/S) process was investigated. The results showed that the cement mixing ratio, curing time and solidifying agents (Na2S and sodium diethyl dithiocarbamate (DDTCNa)) obviously affect the leaching ability of V in spent SCR catalysts. The leaching amount, leaching concentration and leaching rate of V in original spent SCR catalyst are 137.98 mg/kg, 13.79 mg/L and 1.82%, respectively. After the spent SCR catalyst was solidified with cement and cured for 28 days, the leaching concentrations of V in catalyst-cement solidified waste are 2.27 mg/L for 30% of cement addition and 0.14 mg/L for 70% of cement addition, respectively. Increasing cement mixing ratio and curing time could decrease the leaching concentrations of V in the cement solidified waste by affecting the generation of V5+-bearing species, which was identified by XRD, BET, SEM and FTIR. The heavy metal V could be immobilized through the formation of VO 4 3--bearing compounds in hydrating cement matrix. Evaluation on the leaching concentrations of V after adding Na 2 S and DDTCNa in cement solidified waste revealed that Na 2 S and DDTCNa are capable of reducing leaching concentrations of V from 6.25 mg/L to 5.74 mg/L and 4.65 mg/L, respectively. DDTCNa showed a better solidification performance for V compared to Na 2 S. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00162361
- Volume :
- 243
- Database :
- Academic Search Index
- Journal :
- Fuel
- Publication Type :
- Academic Journal
- Accession number :
- 134864163
- Full Text :
- https://doi.org/10.1016/j.fuel.2019.01.160