Objective Nitrobenzene extraction enhanced by salting-out effect was employed to recover aniline from wastewater at 25 ℃. Method Batchwise experiments were conducted to elucidate the influence of various operating va...Objective Nitrobenzene extraction enhanced by salting-out effect was employed to recover aniline from wastewater at 25 ℃. Method Batchwise experiments were conducted to elucidate the influence of various operating variables on the extracting performance, including acidity of wastewater, initial aniline concentration, ratios of solvent to wastewater, extraction stages, concentrations and different types of inorganic salts, such as NaCl, KCI, Na2SO4, CaCl2 and K29O4. Results Nitrobenzene with a concentration of 20% and a pH value of 9.1 at the temperature of 25 ℃ together with NaCl of a concentration of 14 wt.% realized nearly 100% aniline recovery at the fifth stage of wastewater treatment. Conclusions High pH values and volume ratios of nitrobenzene/wastewater are more suitable for recovery of aniline. In addition, recovery of aniline is significantly elevated with increase of the concentration of salts, whose promoting effects are in the following order: NaCI〉Na2SO4〉K2SO4〉CaC12〉KCI on the weight basis of wastewater. Furthermore, aniline in wastewater can be almost completely recovered by five-stage sequential nitrobenzene extraction, which is promoted continuously by the salting-out effect.展开更多
Objective To study the adsorption of 5-Amino-2-chlorotoluene-4-sulfonic (CLT) and chlorhydric (HCl) acids from wastewater by weakly basic resin. Methods The kinetics and isotherm were studied. Thermodynamic parameters...Objective To study the adsorption of 5-Amino-2-chlorotoluene-4-sulfonic (CLT) and chlorhydric (HCl) acids from wastewater by weakly basic resin. Methods The kinetics and isotherm were studied. Thermodynamic parameters for the adsorption of acids were calculated and discussed. Results The adsorption of CLT and HCl acids followed Langmuir isotherm and the first-order kinetics model. Conclusion The adsorptive affinity of the two acids on D301R is in the order of CLT acid 〉 HCl acid. CLT and HCl acids can be separated.展开更多
The evacuation of crowds in a building has always emerged as a vital issue in many accidents. The geometrical structure of a room, especially the exit design has a great influence on crowd evacuation under emergency c...The evacuation of crowds in a building has always emerged as a vital issue in many accidents. The geometrical structure of a room, especially the exit design has a great influence on crowd evacuation under emergency conditions. In this paper, the effect of exit location of a room on crowd evacuation in an emergency is investigated with mice. Two different exits are set in a rectangular chamber. One is located in the middle of a wall(middle-exit) and the other is at the corner of the chamber(corner-exit). Arching and clogging are observed in the flow of mice. The result based on the escape trajectories of mice shows a dynamic balance in the arch near the exit wherever the exit is located. We demonstrate that the occupant position in the arch has an effect on the escape sequence of mice. At a low stimulation level, the narrow middle-exit is more effective in increasing the flow rate of mice than the narrow corner-exit. However, the opposite result appears when the exit becomes wider. At a high stimulation level, the effect of exit location on flow of mice tends to be weakened. The results suggest that the specific level of stimulation needs to be taken into account when optimizing the evacuation efficiency of a crowd through the geometrical structure of a room.展开更多
基金financial support by the National Natural Science Foundation of China(No.52206180)the Fundamental Research Funds for the Central Universities,China(No.WK2320000050)。
基金Supported by the Natural Science Foundation of Shandong Province(No.2006BS08014).
文摘Objective Nitrobenzene extraction enhanced by salting-out effect was employed to recover aniline from wastewater at 25 ℃. Method Batchwise experiments were conducted to elucidate the influence of various operating variables on the extracting performance, including acidity of wastewater, initial aniline concentration, ratios of solvent to wastewater, extraction stages, concentrations and different types of inorganic salts, such as NaCl, KCI, Na2SO4, CaCl2 and K29O4. Results Nitrobenzene with a concentration of 20% and a pH value of 9.1 at the temperature of 25 ℃ together with NaCl of a concentration of 14 wt.% realized nearly 100% aniline recovery at the fifth stage of wastewater treatment. Conclusions High pH values and volume ratios of nitrobenzene/wastewater are more suitable for recovery of aniline. In addition, recovery of aniline is significantly elevated with increase of the concentration of salts, whose promoting effects are in the following order: NaCI〉Na2SO4〉K2SO4〉CaC12〉KCI on the weight basis of wastewater. Furthermore, aniline in wastewater can be almost completely recovered by five-stage sequential nitrobenzene extraction, which is promoted continuously by the salting-out effect.
基金The study was supported by the Nature Science Foundation of Jilin Province (No. 990337).
文摘Objective To study the adsorption of 5-Amino-2-chlorotoluene-4-sulfonic (CLT) and chlorhydric (HCl) acids from wastewater by weakly basic resin. Methods The kinetics and isotherm were studied. Thermodynamic parameters for the adsorption of acids were calculated and discussed. Results The adsorption of CLT and HCl acids followed Langmuir isotherm and the first-order kinetics model. Conclusion The adsorptive affinity of the two acids on D301R is in the order of CLT acid 〉 HCl acid. CLT and HCl acids can be separated.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB1200404)
文摘The evacuation of crowds in a building has always emerged as a vital issue in many accidents. The geometrical structure of a room, especially the exit design has a great influence on crowd evacuation under emergency conditions. In this paper, the effect of exit location of a room on crowd evacuation in an emergency is investigated with mice. Two different exits are set in a rectangular chamber. One is located in the middle of a wall(middle-exit) and the other is at the corner of the chamber(corner-exit). Arching and clogging are observed in the flow of mice. The result based on the escape trajectories of mice shows a dynamic balance in the arch near the exit wherever the exit is located. We demonstrate that the occupant position in the arch has an effect on the escape sequence of mice. At a low stimulation level, the narrow middle-exit is more effective in increasing the flow rate of mice than the narrow corner-exit. However, the opposite result appears when the exit becomes wider. At a high stimulation level, the effect of exit location on flow of mice tends to be weakened. The results suggest that the specific level of stimulation needs to be taken into account when optimizing the evacuation efficiency of a crowd through the geometrical structure of a room.
