Details

Autor(en) / Beteiligte

• Tong, Wenhua
• Wang, Jiepeng
• Du, Xinhang
• Wang, Xuqian
• Wang, Yabo
• Zhang, Yongkui

Titel

Tributyl phosphate degradation and phosphorus immobilization by MnO2: Reaction condition optimization and mechanism exploration

Ist Teil von

• Journal of hazardous materials, 2022-06, Vol.432, p.128725-128725, Article 128725

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The treatment of tributyl phosphate (TBP) extractant waste from specific industry, eg., nuclear industry, is a great challenge due to its stability and high environmental risk of phosphorus-containing species releasing. Inspired by chemical looping combustion (CLC) technology, a MnO2-assisted thermal oxidation strategy is proposed for TBP degradation and simultaneously P immobilization. Under recommended reaction conditions of 220 °C, 10 g MnO2 mL−1 TBP and 3 h reaction duration, a high P immobilization efficiency of 93.99% is achieved. Material characterization results indicate that P is mainly immobilized in the form of Mn2P2O7, which greatly reduces the environmental risk of P-containing species. TBP degradation intermediates are further identified by thermogravimetric-gas chromatography-mass spectrometry (TG-GC-MS), liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS), which facilitates understanding of reaction mechanisms as well as proposing possible pathways of TBP degradation. It is suggested that MnO2 provides essential oxygen as oxygen carrier for flameless combustion. Meantime, MnO2 reduction leads to the generation of Mn(III) species. The existence of oxygen vacancy in MnO2 also facilitates •O2- radical generation. Under flameless combustion and attacks of Mn(III) and •O2-, TBP is firstly degraded into intermediates and finally mineralized into CO2 and H2O, while P is mainly immobilized as pyrophosphate. [Display omitted] •Phosphorus-containing organic waste was treated by CLC technology with MnO2 as oxygen carrier.•Phosphorus in TBP can be immobilized as pyrophosphate with an immobilization efficiency of ~94%.•TBP degradation intermediates were identified.•Mechanisms of TBP degradation and phosphorus immobilization were proposed.