研究了活性炭固定床对水中苯酚的动态吸附特性及影响因素。结果表明,活性炭对苯酚废水的动态吸附随进水苯酚含量和流量的增大穿透时间缩短,但最大设计体积流量不能超过6.47 m L/min;随固定床高度增加,穿透时间推迟,但最小设计高度不能小...研究了活性炭固定床对水中苯酚的动态吸附特性及影响因素。结果表明,活性炭对苯酚废水的动态吸附随进水苯酚含量和流量的增大穿透时间缩短,但最大设计体积流量不能超过6.47 m L/min;随固定床高度增加,穿透时间推迟,但最小设计高度不能小于8 cm。无效层厚度随进水流量和固定床高度的增加而增大,随进水苯酚含量增大而减少。经拟合发现实验结果更符合Yoon-Nelson模型,且相关系数都在0.9以上。展开更多
利用活性炭固定床吸附硝基苯废水溶液,分析了活性炭填充量、硝基苯废水浓度和流量等因素对吸附效果的影响。结果表明,流量越低、活性炭用量越多、硝基苯废水浓度越低,越有利于吸附溶液中的硝基苯。利用Bed Depth Service Time(BDST)、To...利用活性炭固定床吸附硝基苯废水溶液,分析了活性炭填充量、硝基苯废水浓度和流量等因素对吸附效果的影响。结果表明,流量越低、活性炭用量越多、硝基苯废水浓度越低,越有利于吸附溶液中的硝基苯。利用Bed Depth Service Time(BDST)、Tomas、Admas-Bohart和Yoon-Nelson模型对硝基苯废水进行了吸附模拟,效果均较好。展开更多
The study is focused on modeling of separation process and optimization.An adsorption separation process is simulated.The surfactin production process by Bacillus subtilis ATCC 21332 followed by surfactin adsorption i...The study is focused on modeling of separation process and optimization.An adsorption separation process is simulated.The surfactin production process by Bacillus subtilis ATCC 21332 followed by surfactin adsorption in a fixed-bed column packed with commercial active carbon is studied in laboratory.The adsorption column achieves high surfactin recovery(94%)by up-flow methanol elution at 25°C.The adsorption column is simulated with a complex one-dimensional plug flow dispersion model coupled with nonlinear adsorption equilibrium,based on the assumption that the adsorption of surfactin is monomolecular layer and no micelle is formed.The molecular diffusion coefficient of surfactin in water solution with electric neutrality is estimated to be 0.428×10 -5 cm 2 ·s -1 by molecular dynamics simulation.The model developed can describe the complex interplay of adsorption kinetics,fluid dynamics,and mass-transfer phenomena based on the assumption of no radial temperature and concentration gradients,and is of adequate precision.The work involved in this paper is valuable for the optimization of the production process of surfactin.展开更多
The breakthrough curves of benzene and water on modified activated carbons(ACs) were investigated.Temperature-programmed desorption(TPD) experiments were conducted to measure the TPD curves of benzene and water on mod...The breakthrough curves of benzene and water on modified activated carbons(ACs) were investigated.Temperature-programmed desorption(TPD) experiments were conducted to measure the TPD curves of benzene and water on modified and unmodified ACs and to estimate the activation energy for the desorption of benzene on the modified ACs.Starting with unmodified ACs,two modified ACs were prepared by using two different types of silane,designated by KH560 and 1706.The results showed that the activation energy for the desorption of benzene on KH560/AC and 1706/AC was higher than that on unmodified AC.In addition,the activation energy for the desorption of water on KH560/AC and 1706/AC was lower than that on unmodified AC.The breakthrough curves of benzene obtained from the experimental observations under different humidity conditions were compared with the results of the TPD experiments.The results show that the modified ACs are less affected by water,whereas the unmodified ACs are more affected by water,indicating that surface modification by organosilane compounds can improve the adsorption of benzene on the activated carbo,which weakens the adsorption of water.展开更多
文摘研究了活性炭固定床对水中苯酚的动态吸附特性及影响因素。结果表明,活性炭对苯酚废水的动态吸附随进水苯酚含量和流量的增大穿透时间缩短,但最大设计体积流量不能超过6.47 m L/min;随固定床高度增加,穿透时间推迟,但最小设计高度不能小于8 cm。无效层厚度随进水流量和固定床高度的增加而增大,随进水苯酚含量增大而减少。经拟合发现实验结果更符合Yoon-Nelson模型,且相关系数都在0.9以上。
文摘利用活性炭固定床吸附硝基苯废水溶液,分析了活性炭填充量、硝基苯废水浓度和流量等因素对吸附效果的影响。结果表明,流量越低、活性炭用量越多、硝基苯废水浓度越低,越有利于吸附溶液中的硝基苯。利用Bed Depth Service Time(BDST)、Tomas、Admas-Bohart和Yoon-Nelson模型对硝基苯废水进行了吸附模拟,效果均较好。
文摘The study is focused on modeling of separation process and optimization.An adsorption separation process is simulated.The surfactin production process by Bacillus subtilis ATCC 21332 followed by surfactin adsorption in a fixed-bed column packed with commercial active carbon is studied in laboratory.The adsorption column achieves high surfactin recovery(94%)by up-flow methanol elution at 25°C.The adsorption column is simulated with a complex one-dimensional plug flow dispersion model coupled with nonlinear adsorption equilibrium,based on the assumption that the adsorption of surfactin is monomolecular layer and no micelle is formed.The molecular diffusion coefficient of surfactin in water solution with electric neutrality is estimated to be 0.428×10 -5 cm 2 ·s -1 by molecular dynamics simulation.The model developed can describe the complex interplay of adsorption kinetics,fluid dynamics,and mass-transfer phenomena based on the assumption of no radial temperature and concentration gradients,and is of adequate precision.The work involved in this paper is valuable for the optimization of the production process of surfactin.
基金Funded by the National Natural Science Foundation of China (No.20576041)
文摘The breakthrough curves of benzene and water on modified activated carbons(ACs) were investigated.Temperature-programmed desorption(TPD) experiments were conducted to measure the TPD curves of benzene and water on modified and unmodified ACs and to estimate the activation energy for the desorption of benzene on the modified ACs.Starting with unmodified ACs,two modified ACs were prepared by using two different types of silane,designated by KH560 and 1706.The results showed that the activation energy for the desorption of benzene on KH560/AC and 1706/AC was higher than that on unmodified AC.In addition,the activation energy for the desorption of water on KH560/AC and 1706/AC was lower than that on unmodified AC.The breakthrough curves of benzene obtained from the experimental observations under different humidity conditions were compared with the results of the TPD experiments.The results show that the modified ACs are less affected by water,whereas the unmodified ACs are more affected by water,indicating that surface modification by organosilane compounds can improve the adsorption of benzene on the activated carbo,which weakens the adsorption of water.
