It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,...It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).展开更多
采用浸渍法制备负载双金属(铁和铈)活性炭(Fe-Ce/AC),以Fe-Ce/AC为非均相Fenton催化剂处理兰炭废水。在单因素实验基础下,以pH值及H_2O_2和Fe-Ce/AC投加量为考察因素,兰炭废水COD去除率为评价指标,确定H_2O_2最佳投加量为3 m L,Fe-Ce/A...采用浸渍法制备负载双金属(铁和铈)活性炭(Fe-Ce/AC),以Fe-Ce/AC为非均相Fenton催化剂处理兰炭废水。在单因素实验基础下,以pH值及H_2O_2和Fe-Ce/AC投加量为考察因素,兰炭废水COD去除率为评价指标,确定H_2O_2最佳投加量为3 m L,Fe-Ce/AC最佳投加量为0.10 g,pH最佳值为4。采用中心组合设计-响应曲面法优化Fe-Ce/AC非均相Fenton技术处理兰炭废水工艺,结果表明,各影响因子显著性顺序为:pH>Fe-Ce/AC投加量>H_2O_2投加量,其中,H_2O_2投加量与Fe-Ce/AC投加量间交互作用显著,模型校正决定系数R2adj=为0.920 9,模型回归项极显著(P<0.000 1),表明模型可信度和准确度高;最佳工艺条件为:pH=3.7,H_2O_2投加量为2.7 m L,Fe-Ce/AC投加量为0.1 g,COD去除率模型预测值为81.31%,与实验值80.05%相比,相对误差为1.55%,表明模型对实验结果有良好的预测性。展开更多
In the present work, a novel heterogeneous photo-Fenton catalyst was prepared by iron and cerium pillared bentonite. The catalyst Fe-Ce/bentonite was characterized by X-ray diffraction （XRD）, X-ray fluorescence （XR...In the present work, a novel heterogeneous photo-Fenton catalyst was prepared by iron and cerium pillared bentonite. The catalyst Fe-Ce/bentonite was characterized by X-ray diffraction （XRD）, X-ray fluorescence （XRF）, Brunauer-Emmett-Teller （BET） and scanning electron microscopy （SEM） methods. It is found that Fe and Ce intercalate into the silicate layers of bentonite successfully. Tetracycline was removed by heterogeneous photo-Fenton reaction using the catalyst in this work. The effects of different reaction systems, hydrogen peroxide concentration, initial pH, catalyst dosage, UV power and introduction of different anions on degradation were investigated in details. The stability of catalyst was investigated through recycling experiment. The results show that removal rate of tetracycline is 98.13% under the conditions of 15 mmol/L H202, 0.50 g/L catalyst dosage, initial pH 3.0, 11 W UV lamp power and 60 min reaction time. However, the removal rate decreases after adding some anions. The hydroxyl radical plays an important role in heterogeneous photo-assisted Fenton degradation of tetracycline. The catalyst is very stable and can be recycled many times.展开更多
文摘It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).
文摘采用浸渍法制备负载双金属(铁和铈)活性炭(Fe-Ce/AC),以Fe-Ce/AC为非均相Fenton催化剂处理兰炭废水。在单因素实验基础下,以pH值及H_2O_2和Fe-Ce/AC投加量为考察因素,兰炭废水COD去除率为评价指标,确定H_2O_2最佳投加量为3 m L,Fe-Ce/AC最佳投加量为0.10 g,pH最佳值为4。采用中心组合设计-响应曲面法优化Fe-Ce/AC非均相Fenton技术处理兰炭废水工艺,结果表明,各影响因子显著性顺序为:pH>Fe-Ce/AC投加量>H_2O_2投加量,其中,H_2O_2投加量与Fe-Ce/AC投加量间交互作用显著,模型校正决定系数R2adj=为0.920 9,模型回归项极显著(P<0.000 1),表明模型可信度和准确度高;最佳工艺条件为:pH=3.7,H_2O_2投加量为2.7 m L,Fe-Ce/AC投加量为0.1 g,COD去除率模型预测值为81.31%,与实验值80.05%相比,相对误差为1.55%,表明模型对实验结果有良好的预测性。
基金Project(51004053)supported by National Natural Science Foundation of ChinaProject(2009J01033)supported by Natural Science Foundation of Fujian Province,China+2 种基金Project(3502Z20116008)supported by the Science and Technology Research Project of Xiamen City,ChinaProject(JA11146)supported by Program for Fostering Distinguished Young Scholars in University of Fujian Province,ChinaProject(2011B003)supported by the Foundation for Young Professors of Jimei University,China
文摘In the present work, a novel heterogeneous photo-Fenton catalyst was prepared by iron and cerium pillared bentonite. The catalyst Fe-Ce/bentonite was characterized by X-ray diffraction （XRD）, X-ray fluorescence （XRF）, Brunauer-Emmett-Teller （BET） and scanning electron microscopy （SEM） methods. It is found that Fe and Ce intercalate into the silicate layers of bentonite successfully. Tetracycline was removed by heterogeneous photo-Fenton reaction using the catalyst in this work. The effects of different reaction systems, hydrogen peroxide concentration, initial pH, catalyst dosage, UV power and introduction of different anions on degradation were investigated in details. The stability of catalyst was investigated through recycling experiment. The results show that removal rate of tetracycline is 98.13% under the conditions of 15 mmol/L H202, 0.50 g/L catalyst dosage, initial pH 3.0, 11 W UV lamp power and 60 min reaction time. However, the removal rate decreases after adding some anions. The hydroxyl radical plays an important role in heterogeneous photo-assisted Fenton degradation of tetracycline. The catalyst is very stable and can be recycled many times.
