Ammonia in wastewater is a major pollutant produced in industrial and agricultural wastewaters. Ammonia is often removed by conventional technologies such as pack tower aeration, biological treatment or adsorption as ...Ammonia in wastewater is a major pollutant produced in industrial and agricultural wastewaters. Ammonia is often removed by conventional technologies such as pack tower aeration, biological treatment or adsorption as ammonium ion onto zeolites. In many cases, conventional methods are very costly and inefficient, and therefore there is a need for an alternative separation technique for more efficient removal of ammonia from wastewaters. The aim of this study is to investigate the performance of combination of ozonation and absorption through membrane processes to remove ammonia from wastewater using NHSW （natural hot spring water） as absorbent. Experimental results show that hollow fiber membrane contactor has potential application for ammonia removal from wastewater. Operating variables such as time and pH of absorbent solution are found to remarkably influence the removal process efficiency.. Based on experimental results ozonation can improve ammonia removal efficiency through hollow fiber membrane contactor. Ammonia removal efficiencies and overall mass transfer coefficients increase with decreasing pH of absorbent solution.展开更多
In a spouted bed of 80mm in ID and 1700mm in height, the gas residence time distributions at different radial positions in both spout and annular area were measured with five different kinds of particles as spouting m...In a spouted bed of 80mm in ID and 1700mm in height, the gas residence time distributions at different radial positions in both spout and annular area were measured with five different kinds of particles as spouting material, air as spouting gas, and hydrogen as tracer. The effects of superficial gas velocity, operating pressure, particle size and its category on gas residence time distribution were discussed. It was found that the gas velocity profile in spout was more uniform than that in annulus. It could be concluded that the gas flow in the spout could be treated as a plug-flow, while that in the annulus inhibited a strong non-ideal flow behavior. Increasing the superficial gas velocity and decreasing the operating pressure, the particle density and its size gave rise to spouting disturbance, thus the measured tracer concentrations vs. time curves fluctuated. The variances of residence time distribution curves could be taken as a measure of the gas fluctuation degree.展开更多
Objective:To observe the clinical efficacy of Zhen'ai needling method in Nei Jing(Classic of Internal Medicine)for children with allergic rhinitis(AR)accompanied by adenoid hypertrophy(AH).Methods:A total of 74 ch...Objective:To observe the clinical efficacy of Zhen'ai needling method in Nei Jing(Classic of Internal Medicine)for children with allergic rhinitis(AR)accompanied by adenoid hypertrophy(AH).Methods:A total of 74 children who met the screening criteria were divided into a Zhen'ai group and a control group by the random number table method,with 37 cases in each group.The control group was treated with acupuncture at Zusanli(ST 36),Hegu(LI 4),Yingxiang(LI 20),Juliao(ST 3),Yintang(GV 29),Shangxing(GV 23)and Baihui(GV 20).The Zhen'ai group added points of Zhen'ai needling method{Shanglianquan[Extra,located at 1 cun above Lianquan(CV 23)],Tianrong(SI 17)and Lieque(LU 7)}in addition to the points in the control group.The needles were retained for 30 min.The treatment was performed twice a week.The total nasal symptom score(TNSS),sino-nasal outcome test-20(SNOT-20)and symptom scale for AH(SSAH)were assessed before and after 10 treatments.The clinical efficacy of the two groups was compared after treatment.Results:During the treatment,5 cases dropped out in the control group and 2 cases in the Zhen'ai group.After treatment,the total effective rate of the Zhen'ai group was 94.3%,versus 93.8%in the control group.There was no significant difference between the two groups(P>0.05).The markedly effective rate of the Zhen'ai group was 42.9%,versus 12.5%in the control group,and the difference was statistically significant(P<0.05).After treatment,there were significant intra-group differences in the scores of TNSS,SNOT-20 and SSAH in both groups(all P<0.05);the scores of SNOT-20 and SSAH in the Zhen'ai group were lower than those in the control group,and the differences between the groups were statistically significant(both P<0.05).Conclusion:Both conventional acupuncture and conventional acupuncture plus Zhen'ai needling method can improve clinical symptoms of children with AR accompanied by AH;and conventional acupuncture plus Zhen'ai needling method has a better effect than conventional acupuncture in improving AH symptoms.展开更多
文摘Ammonia in wastewater is a major pollutant produced in industrial and agricultural wastewaters. Ammonia is often removed by conventional technologies such as pack tower aeration, biological treatment or adsorption as ammonium ion onto zeolites. In many cases, conventional methods are very costly and inefficient, and therefore there is a need for an alternative separation technique for more efficient removal of ammonia from wastewaters. The aim of this study is to investigate the performance of combination of ozonation and absorption through membrane processes to remove ammonia from wastewater using NHSW （natural hot spring water） as absorbent. Experimental results show that hollow fiber membrane contactor has potential application for ammonia removal from wastewater. Operating variables such as time and pH of absorbent solution are found to remarkably influence the removal process efficiency.. Based on experimental results ozonation can improve ammonia removal efficiency through hollow fiber membrane contactor. Ammonia removal efficiencies and overall mass transfer coefficients increase with decreasing pH of absorbent solution.
基金Supported by the National Natural Science Foundation of China (No. 20490201) the Ministry of Education of China through the Doctorate Discipline Foundation (No. 2000042503).
文摘In a spouted bed of 80mm in ID and 1700mm in height, the gas residence time distributions at different radial positions in both spout and annular area were measured with five different kinds of particles as spouting material, air as spouting gas, and hydrogen as tracer. The effects of superficial gas velocity, operating pressure, particle size and its category on gas residence time distribution were discussed. It was found that the gas velocity profile in spout was more uniform than that in annulus. It could be concluded that the gas flow in the spout could be treated as a plug-flow, while that in the annulus inhibited a strong non-ideal flow behavior. Increasing the superficial gas velocity and decreasing the operating pressure, the particle density and its size gave rise to spouting disturbance, thus the measured tracer concentrations vs. time curves fluctuated. The variances of residence time distribution curves could be taken as a measure of the gas fluctuation degree.
文摘Objective:To observe the clinical efficacy of Zhen'ai needling method in Nei Jing(Classic of Internal Medicine)for children with allergic rhinitis(AR)accompanied by adenoid hypertrophy(AH).Methods:A total of 74 children who met the screening criteria were divided into a Zhen'ai group and a control group by the random number table method,with 37 cases in each group.The control group was treated with acupuncture at Zusanli(ST 36),Hegu(LI 4),Yingxiang(LI 20),Juliao(ST 3),Yintang(GV 29),Shangxing(GV 23)and Baihui(GV 20).The Zhen'ai group added points of Zhen'ai needling method{Shanglianquan[Extra,located at 1 cun above Lianquan(CV 23)],Tianrong(SI 17)and Lieque(LU 7)}in addition to the points in the control group.The needles were retained for 30 min.The treatment was performed twice a week.The total nasal symptom score(TNSS),sino-nasal outcome test-20(SNOT-20)and symptom scale for AH(SSAH)were assessed before and after 10 treatments.The clinical efficacy of the two groups was compared after treatment.Results:During the treatment,5 cases dropped out in the control group and 2 cases in the Zhen'ai group.After treatment,the total effective rate of the Zhen'ai group was 94.3%,versus 93.8%in the control group.There was no significant difference between the two groups(P>0.05).The markedly effective rate of the Zhen'ai group was 42.9%,versus 12.5%in the control group,and the difference was statistically significant(P<0.05).After treatment,there were significant intra-group differences in the scores of TNSS,SNOT-20 and SSAH in both groups(all P<0.05);the scores of SNOT-20 and SSAH in the Zhen'ai group were lower than those in the control group,and the differences between the groups were statistically significant(both P<0.05).Conclusion:Both conventional acupuncture and conventional acupuncture plus Zhen'ai needling method can improve clinical symptoms of children with AR accompanied by AH;and conventional acupuncture plus Zhen'ai needling method has a better effect than conventional acupuncture in improving AH symptoms.
