Heterogeneous Fenton-like discoloration of methyl orange using Fe3O4/MWCNTs as catalyst： process optimization by response surface methodology

Fe3O4/MWCNTs nanocomposites were prepared by chemical oxidation coprecipitation method and developed as highly efficient heterogeneous Fenton-like catalyst. XRD results revealed that Fe3O4 nanoparticles deposited onto MWCNTs surface remained the inverse spinel crystal structure of cubic Fe3O4 phase. The FTIR characteristic peaks of MWCNTs weakened or disappeared due to the anchor of Fe3O4 nanoparticles and Fe-O peak at 570 cm^-1 was indicative of the formation of Fe3O4. TEM observation revealed that Fe3O4 nanoparticles were tightly anchored by MWCNTs. The Fenton-like catalytic activity of Fe3O4/MWCNTs nanocomposites for the discoloration of methyl orange （MO） was much higher than that of Fe3O4 nanoparticles. The process optimization of this heterogeneous Fenton-like system was implemented by response surface methodology （RSM）. The optimum conditions for MO discoloration were determined to be of 12.3 mmoi/L H2O2 concentration, 2.9 glL catalyst dosage, solution pH 2.7 and 39.3 min reaction time, with the maximum predicted value for MO discoloration ratio of 101.85%. The corresponding experimental value under the identical conditions was obtained as 99.86%, which was very close to the predicted one with the absolute deviation of 1.99%.

三维铜配位聚合物类芬顿反应催化降解刚果红

一个三维铜配位聚合物,[Cu2(btec)(btx)1.5]n(H4btec=均苯四酸,btx=1,4-二(1,2,4-三氮唑-1-亚甲基)苯)可以作为类芬顿体系催化剂,降解偶氮染料刚果红,考察了初始pH、催化剂用量、H2O2的浓度、染料初始浓度及反应温度等因素对刚果红降解率的影响。结果表明在最佳条件下,刚果红溶液的降解效率接近100%。

非均相催化湿式氧化活性红2BF的研究

以Fe/AC为催化剂、O2为氧化剂的非均相催化氧化体系处理偶氮染料活性红2BF,考察了反应温度、氧分压、废水pH、催化剂投加量等因素对降解效果的影响。结果表明,染料初始质量浓度为400 mg/L时,在温度150℃、氧分压0.5 MPa、pH=3、反应时间60 min、催化剂投加量为4 g/L的最佳条件下,活性红2BF色度几乎完全去除,TOC去除率达94.21%。