The influencing factors and kinetics of oxidative degradation of ammonia nitrogen in high salinity wastewater by sodium hypochlorite oxidation( Na Cl O) were studied. The results showed that the degradation process of...The influencing factors and kinetics of oxidative degradation of ammonia nitrogen in high salinity wastewater by sodium hypochlorite oxidation( Na Cl O) were studied. The results showed that the degradation process of ammonia nitrogen by sodium hypochlorite accorded with a pseudo first-order kinetics model,and the influencing factors included Na Cl O dosage,initial concentration of ammonia nitrogen,salinity,temperature,and so on. When Na Cl O dosage was 0. 6%( MCl∶ MN= 13. 76),the reaction rate constant was up to 0. 015 75 min^(-1). The higher the initial concentration of ammonia nitrogen was,the worse the effect of oxidation reaction was. When the initial concentration did not exceed 45 mg/L,the effect on oxidation reaction rate constant increased with the increase of the initial concentration. Low salinity had no effect on ammonia nitrogen oxidation.When salinity was higher than 2. 0%,the inhibition effect on ammonia nitrogen oxidation would increase,and the reaction rate constant decreased obviously with the increase of salinity. The improvement of reaction temperature was beneficial to ammonia oxidation degradation. As temperature increased from 10 to 35 ℃,the reaction rate constant rose from 0. 00188 to 0. 01043 min^(-1).展开更多
Based on the traditional method of high concentration ammonia removal from wastewater,a mixture mainly consisting of ethyl lactate and acetic acid is used as an aid for ammonia removal by air stripping.The effect of d...Based on the traditional method of high concentration ammonia removal from wastewater,a mixture mainly consisting of ethyl lactate and acetic acid is used as an aid for ammonia removal by air stripping.The effect of dosage,the depth of air nozzle in water and other conditions for ammonia removal were investigated.The results show that under the conditions that denitrification reagent is in the dosage of 30 mg/L,pH value is 9-11,blowing depth is 400 mm,stripping time is greater than 2.5 h,and the temperature is normal(25°C),the concentration of ammonia nitrogen in wastewater can be reduced from 21006.0 mg/L to 10.6 mg/L. The ammonia nitrogen removal rate is up to 99.95%.At the temperature of 45°C,the concentration of ammonia nitrogen in wastewater can be decreased from 21006 mg/L to 0.2 mg/L.The ammonia nitrogen removal rate is up to 99.999%.When the wastewater ammonia concentration is between 800-30000 mg/L,the ammonia is air stripped under the above mentioned conditions,the residual concentration can be below 15 mg/L.The stripped ammonia can be absorbed without secondary pollution.展开更多
基金Supported by Project for Achievement Transformation of High and New Technology in Shanghai City(201405267)
文摘The influencing factors and kinetics of oxidative degradation of ammonia nitrogen in high salinity wastewater by sodium hypochlorite oxidation( Na Cl O) were studied. The results showed that the degradation process of ammonia nitrogen by sodium hypochlorite accorded with a pseudo first-order kinetics model,and the influencing factors included Na Cl O dosage,initial concentration of ammonia nitrogen,salinity,temperature,and so on. When Na Cl O dosage was 0. 6%( MCl∶ MN= 13. 76),the reaction rate constant was up to 0. 015 75 min^(-1). The higher the initial concentration of ammonia nitrogen was,the worse the effect of oxidation reaction was. When the initial concentration did not exceed 45 mg/L,the effect on oxidation reaction rate constant increased with the increase of the initial concentration. Low salinity had no effect on ammonia nitrogen oxidation.When salinity was higher than 2. 0%,the inhibition effect on ammonia nitrogen oxidation would increase,and the reaction rate constant decreased obviously with the increase of salinity. The improvement of reaction temperature was beneficial to ammonia oxidation degradation. As temperature increased from 10 to 35 ℃,the reaction rate constant rose from 0. 00188 to 0. 01043 min^(-1).
基金supported by Water Pollution Control and Management of Chinese Special Key Science and Technology Project(2008ZX07101007-01)
文摘Based on the traditional method of high concentration ammonia removal from wastewater,a mixture mainly consisting of ethyl lactate and acetic acid is used as an aid for ammonia removal by air stripping.The effect of dosage,the depth of air nozzle in water and other conditions for ammonia removal were investigated.The results show that under the conditions that denitrification reagent is in the dosage of 30 mg/L,pH value is 9-11,blowing depth is 400 mm,stripping time is greater than 2.5 h,and the temperature is normal(25°C),the concentration of ammonia nitrogen in wastewater can be reduced from 21006.0 mg/L to 10.6 mg/L. The ammonia nitrogen removal rate is up to 99.95%.At the temperature of 45°C,the concentration of ammonia nitrogen in wastewater can be decreased from 21006 mg/L to 0.2 mg/L.The ammonia nitrogen removal rate is up to 99.999%.When the wastewater ammonia concentration is between 800-30000 mg/L,the ammonia is air stripped under the above mentioned conditions,the residual concentration can be below 15 mg/L.The stripped ammonia can be absorbed without secondary pollution.
