Abstract:In order to solve the difficult problems of denitrification from aged-landfill leachate, a pilot experiment on stripping of ammonia from aged-landfill leachate was carried out by dynamic wave stripping technology. In this study, the effects of stripping time, pH, gas-liquid ratio, temperature and concentration of influent ammonia nitrogen concentration on stripping efficiency were investigated. The results of the single factor experiment showed that the stripping removal rate increased rapidly in the first 3 hours, and changed little after 5 hours. The proportion of free ammonia increased at high pH, which was more beneficial for stripping, and the most economical stripping result occurred a pH of around 10.5. The applicable temperature range of dynamic wave stripping was wide, the removel efficiencies could reach 72.62% and 90.68% at 10 ℃ and 25 ℃, respectively. The stripping efficiency could be improved by increasing the gas-liquid ratio, but when it was above 129, the insignificant increase of gas-liquid specific stripping effect occurred. The concentration of influent ammonia nitrogen concentration within the examined range had slight effect on ammonia stripping. The results of orthogonal test demonstrated that the temperature variance was the largest, the variances of pH and gas-liquid ratio were the second, and the variance of influent ammonia nitrogen concentration was the smallest. Therefore, the most influence factor on stripping was temperature, then the second ones were pH and gas-liquid ratio, and the final one was initial ammonia nitrogen concentration. Compared with traditional stripping process, the optimum conditions of stripping process were 25 ℃, pH 10.5, gas-liquid ratio of 129 and stripping time of 5 h, and the corresponding total removal rate of ammonia nitrogen could reach 91.25%~94.15% with enhanced separation efficiency of ammonia nitrogen. Key words:aged-landfill leachate/ ammonia nitrogen/ denitrification/ dynamic wave/ stripping.
图1动力波吹脱中试研究装置 Figure1.Pilot equipment for dynamic wave stripping
RENOU S, GIVAUDAN J G, POULAIN S, et al. Landfill leachate treatment: Review and opportunity[J]. Journal of Hazardous Materials, 2008, 150(3): 468-493. doi: 10.1016/j.jhazmat.2007.09.077
[2]
JUNG C, DENG Y, ZHAO R, et al. Chemical oxidation for mitigation of UV-quenching substances (UVQS) from municipal landfill leachate: Fenton process versus ozonation[J]. Water Research, 2017, 108: 260-270. doi: 10.1016/j.watres.2016.11.005
[3]
DENG Y, ENGLEHARDT J D. Treatment of landfill leachate by the Fenton process[J]. Water Research, 2006, 40(20): 3683-3694. doi: 10.1016/j.watres.2006.08.009
[4]
OULEGO P, COLLADO S, LACA A, et al. Impact of leachate composition on the advanced oxidation treatment[J]. Water Research, 2016, 88: 389-402. doi: 10.1016/j.watres.2015.09.048
[5]
LOGANATHAN P, VIGNESWARAN S, KANDASAMY J. Enhanced removal of nitrate from water using surface modification of adsorbents: A review[J]. Journal of Environmental Management, 2013, 131: 363-374.
[6]
REIS P M, MARTINS P J M, MARTINS R C, et al. Integrating Fenton’s process and ion exchange for olive mill wastewater treatment and iron recovery[J]. Environmental Technology, 2018, 39(3): 308-316. doi: 10.1080/09593330.2017.1299797
XIU-FEN L, BARNES D, JIAN C. Performance of struvite precipitation during pretreatment of raw landfill leachate and its biological validation[J]. Environmental Chemistry Letters, 2011, 9(1): 71-75. doi: 10.1007/s10311-009-0248-4
OZTURK I, ALTINBAS M, KOYUNCU I, et al. Advanced physico-chemical treatment experiences on young municipal landfill leachates[J]. Waste Management, 2003, 23(5): 441-446. doi: 10.1016/S0956-053X(03)00061-8
[11]
AHMED F N, LAN C Q. Treatment of landfill leachate using membrane bioreactors: A review[J]. Desalination, 2012, 287: 41-54. doi: 10.1016/j.desal.2011.12.012
FERRAZ F M, POVINELLI J, VIEIRA E M. Ammonia removal from landfill leachate by air stripping and absorption[J]. Environmental Technology, 2013, 34(13/14): 2317-2326.
[18]
LI A F, NING Y Y, XU W J, et al. Air stripping of ammoniacal nitrogen from fecal sewage using a fluidized bed[J]. Advanced Materials Research, 2014, 926-930: 4209-4213. doi: 10.4028/www.scientific.net/AMR.926-930.4209
MARTTINEN S K, KETTUNEN R H, SORMUNEN K M, et al. Screening of physical-chemical methods for removal of organic material, nitrogen and toxicity from low strength landfill leachates[J]. Chemosphere, 2002, 46(6): 851-858. doi: 10.1016/S0045-6535(01)00150-3
WANG T F, WANG J F, YANG W G, et al. Bubble behavior in gas-liquid-solid three-phase circulating fluidized beds[J]. Chemical Engineering Journal, 2001, 84(3): 397-404.
1.College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350118, China 2.Fuzhou City Construction Design and Research Institute Co. Ltd., Fuzhou 350118, China Received Date: 2019-12-17 Accepted Date: 2020-05-09 Available Online: 2020-11-11 Keywords:aged-landfill leachate/ ammonia nitrogen/ denitrification/ dynamic wave/ stripping Abstract:In order to solve the difficult problems of denitrification from aged-landfill leachate, a pilot experiment on stripping of ammonia from aged-landfill leachate was carried out by dynamic wave stripping technology. In this study, the effects of stripping time, pH, gas-liquid ratio, temperature and concentration of influent ammonia nitrogen concentration on stripping efficiency were investigated. The results of the single factor experiment showed that the stripping removal rate increased rapidly in the first 3 hours, and changed little after 5 hours. The proportion of free ammonia increased at high pH, which was more beneficial for stripping, and the most economical stripping result occurred a pH of around 10.5. The applicable temperature range of dynamic wave stripping was wide, the removel efficiencies could reach 72.62% and 90.68% at 10 ℃ and 25 ℃, respectively. The stripping efficiency could be improved by increasing the gas-liquid ratio, but when it was above 129, the insignificant increase of gas-liquid specific stripping effect occurred. The concentration of influent ammonia nitrogen concentration within the examined range had slight effect on ammonia stripping. The results of orthogonal test demonstrated that the temperature variance was the largest, the variances of pH and gas-liquid ratio were the second, and the variance of influent ammonia nitrogen concentration was the smallest. Therefore, the most influence factor on stripping was temperature, then the second ones were pH and gas-liquid ratio, and the final one was initial ammonia nitrogen concentration. Compared with traditional stripping process, the optimum conditions of stripping process were 25 ℃, pH 10.5, gas-liquid ratio of 129 and stripping time of 5 h, and the corresponding total removal rate of ammonia nitrogen could reach 91.25%~94.15% with enhanced separation efficiency of ammonia nitrogen.
下载: 
点击查看大图
