低温地下水净化工艺中氨氮去除性能及机制  

Removal Efficiency and Mechanism of Ammonia Nitrogen in a Low Temperature Groundwater Purification Process

作　　者：李冬[1] 刘孟浩 张瑞苗 曾辉平[1] 张杰[1,2] LI Dong;LIU Meng-hao;ZHANG Rui-miao;ZENG Hui-ping;ZHANG Jie(Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering,Faculty of Architecture,Civil and Transportation Engineering,Beijing University of Technology,Beijing 100124,China;State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150090,China)

机构地区：[1]北京工业大学城市建设学部,水质科学与水环境恢复工程北京市重点实验室,北京100124 [2]哈尔滨工业大学环境学院,城市水资源与水环境国家重点实验室,哈尔滨150090

出　　处：《环境科学》2021年第10期4826-4833,共8页Environmental Science

基　　金：国家自然学科基金项目(51678006)。

摘　　要：在东北某自来水厂,以中试滤柱开展了低温(5~6℃)高铁锰氨[Fe(Ⅱ)11.9~14.8 mg·L^(-1)、Mn(Ⅱ)1.1~1.5 mg·L^(-1)和NH4+-N 1.1~3.2 mg·L^(-1)]净化工艺实验,以探究氨氮去除途径与生物滤柱的除氨性能.结果表明,滤柱在启动初期就对氨氮具有良好的去除效果,通过理论分析与实验验证可知,TNloss是由铁氧化物对氨氮吸附造成,氨氮转化为硝氮的过程是生物硝化作用.氨氮质量浓度提高过程中,由于吸附位点有限,铁氧化物对氨氮的吸附量稳定在1 mg·L^(-1)左右,氨氮氧化去除量不断增加,其中在滤柱上部滤层的去除量远大于下部滤层,DO是限制氨氮氧化去除量进一步增加的限制因素.滤速提升过程中,铁氧化物对氨氮吸附时间缩短,吸附量有所减少,空床接触时间(empty bed contact time,EBCT)缩短,使得单位体积滤料中硝化菌硝化去除的氨氮减少,需要增加滤层厚度以提升氨氮去除效果.To explore the mechanism and efficiency of ammonia nitrogen removal,a pilot-scale biofilter for the simultaneous removal of high concentrations of iron,manganese,and ammonia nitrogen[Fe(Ⅱ)11.9-14.8 mg·L^(-1),Mn(Ⅱ)1.1-1.5 mg·L^(-1),and NH4+-N 1.1-3.2 mg·L^(-1)]from low temperature(5-6℃)groundwater was operated in a water supply plant in Northeast China.Results indicated excellent performance for ammonia nitrogen removal during the initial start-up stage.According to theoretical analysis and experimental verification,TNloss was driven by the adsorption of ammonia nitrogen by iron oxides,and the conversion of ammonia nitrogen into nitrate nitrogen occurred via biological nitrification.When the concentration of ammonia nitrogen increased,due to limited adsorption sites,the adsorption capacity of iron oxides remained stable at approximately 1 mg·L^(-1).For the same period,the amount of ammonia nitrogen removal via oxidation continued to increase,with higher quantities removed in the upper filter layer than in the lower filter layer.Dissolved oxygen(DO)is the limiting factor in the further increase in the removal of ammonia nitrogen by oxidation.With an increase in the filtration rate,the adsorption time of ammonia nitrogen by iron oxides was shortened,and the adsorption amount was reduced.Meanwhile,the shortening of EBCT reduced the ammonia nitrogen removed by nitrification under the action of nitrifying bacteria in the unit volume of the filter material.Based on these findings,it is recommended that the thickness of the filter layer should be increased to improve ammonia nitrogen removal performance.

关 键 词：地下水处理 高铁锰 氨氮 生物硝化 吸附 

分 类 号：X523[环境科学与工程—环境工程]