A batch fixed bed photoreactor,using felt-form activated carbon fibers(ACF)supported TiO2 photocatalyst(TiO2/ACF),was developed to carry out photocatalytic degradation of methylene blue(MB)solution.The effects of TiO2...A batch fixed bed photoreactor,using felt-form activated carbon fibers(ACF)supported TiO2 photocatalyst(TiO2/ACF),was developed to carry out photocatalytic degradation of methylene blue(MB)solution.The effects of TiO2 particle size,loaded TiO2 amount,initial MB concentration,airflow rate and successive run on the decomposition rate were investigated.The results showed that photodegradation process followed a pseudo-first-order reaction kinetic law.The apparent first-order reaction constant kapp was larger than 0.047 min- 1 with half reaction time t1/2 shorter than 15 min,which was comparable to reported data using suspended Degussa P-25 TiO2 particles.The high degradation rate was mainly attributed to adsorption of MB molecules onto the surface of TiO2/ACF.The photocatalytic efficiency still remained nearly 90%after 12 successive runs,showing that successive usage of the designed photoreactor was possible.The synergic enhancement effect in combination of adsorption with ACF and photodegradation with TiO2 was proved by comparing MB removal rates in the successive degradation and adsorption runs,respectively.展开更多
使用戊二醛为交联剂,将黑荆树单宁(BWT)固化在胶原纤维(CF)表面,得到新型硼同位素分离树脂CF-BWT。通过FTIR、XPS、SEM、^(11)B MAS NMR分析,探究了CF-BWT吸附硼前后表面元素组成、形貌结构以及吸附机理等。研究结果表明,当pH为8.0,硼...使用戊二醛为交联剂,将黑荆树单宁(BWT)固化在胶原纤维(CF)表面,得到新型硼同位素分离树脂CF-BWT。通过FTIR、XPS、SEM、^(11)B MAS NMR分析,探究了CF-BWT吸附硼前后表面元素组成、形貌结构以及吸附机理等。研究结果表明,当pH为8.0,硼初始浓度为110mg/L时,CF-BWT的平衡吸附量可达1.9mg/g。吸附平衡符合Langmuir模型,平衡吸附量随温度升高而增加。吸附动力学可用准二级动力学模型描述,由模型计算得到的平衡吸附量与实验值接近。进一步研究发现,CF-BWT表面固化的黑荆树单宁与硼形成硼-单宁活性交换界面,促使^(10)B和^(11)B发生同位素交换反应,从而将^(10)B富集于CF-BWT表面,实现^(10)B和^(11)B的分离。当pH为7.0时,CF-BWT对^(10)B和^(11)B的单级分离因子可达1.17。当初始硼同位素丰度比(^(10)B/^(11)B)为0.2180时,以CF-BWT为填料的固定床对^(10)B和^(11)B进行分离,发现穿透段硼同位素丰度比(^(10)B/^(11)B)为0.2149,而在洗脱段则达到0.2234。展开更多
基金Beijing Excellent Talents Training Fund(No.20061D0502200299)
文摘A batch fixed bed photoreactor,using felt-form activated carbon fibers(ACF)supported TiO2 photocatalyst(TiO2/ACF),was developed to carry out photocatalytic degradation of methylene blue(MB)solution.The effects of TiO2 particle size,loaded TiO2 amount,initial MB concentration,airflow rate and successive run on the decomposition rate were investigated.The results showed that photodegradation process followed a pseudo-first-order reaction kinetic law.The apparent first-order reaction constant kapp was larger than 0.047 min- 1 with half reaction time t1/2 shorter than 15 min,which was comparable to reported data using suspended Degussa P-25 TiO2 particles.The high degradation rate was mainly attributed to adsorption of MB molecules onto the surface of TiO2/ACF.The photocatalytic efficiency still remained nearly 90%after 12 successive runs,showing that successive usage of the designed photoreactor was possible.The synergic enhancement effect in combination of adsorption with ACF and photodegradation with TiO2 was proved by comparing MB removal rates in the successive degradation and adsorption runs,respectively.
文摘使用戊二醛为交联剂,将黑荆树单宁(BWT)固化在胶原纤维(CF)表面,得到新型硼同位素分离树脂CF-BWT。通过FTIR、XPS、SEM、^(11)B MAS NMR分析,探究了CF-BWT吸附硼前后表面元素组成、形貌结构以及吸附机理等。研究结果表明,当pH为8.0,硼初始浓度为110mg/L时,CF-BWT的平衡吸附量可达1.9mg/g。吸附平衡符合Langmuir模型,平衡吸附量随温度升高而增加。吸附动力学可用准二级动力学模型描述,由模型计算得到的平衡吸附量与实验值接近。进一步研究发现,CF-BWT表面固化的黑荆树单宁与硼形成硼-单宁活性交换界面,促使^(10)B和^(11)B发生同位素交换反应,从而将^(10)B富集于CF-BWT表面,实现^(10)B和^(11)B的分离。当pH为7.0时,CF-BWT对^(10)B和^(11)B的单级分离因子可达1.17。当初始硼同位素丰度比(^(10)B/^(11)B)为0.2180时,以CF-BWT为填料的固定床对^(10)B和^(11)B进行分离,发现穿透段硼同位素丰度比(^(10)B/^(11)B)为0.2149,而在洗脱段则达到0.2234。
