摘要
干湿交替的回灌方法常被用于解决地面回灌补给地下水的堵塞问题。研究干湿交替条件下地面回灌对地下水的影响对于指导再生水回灌地下水具有重要实际意义。通过室内土柱模拟实验,在入渗强度为10.5 mm/h的条件下,日均进水量3 888 mL;用干湿交替的地面回灌模式持续运行136 d,累计灌入氨氮含量为5 mg/L的模拟再生水23 894 L,研究包气带土柱对氨氮的去除效果及氮素在包气带中的迁移转化规律。研究表明,充分利用包气带的好氧、兼氧和厌氧环境,生物脱氮是地下水回灌过程中脱氮的主要途径。包气带对氨氮的去除机理主要为土壤对氨氮的吸附作用和微生物的降解作用。回灌过程中累积在土颗粒表面的氨氮在干期发生硝化作用,干湿交替会加强氮素在包气带的迁移转化,导致干期后的回灌初期大量硝态氮迁移到饱和带地下水中。
The way of alternative leaching and drying has been widely used to solve the clogging problem of surface groundwater recharge.A column experiment was conducted under a constant recharge rate of 10.5 mm/h to understand the treatment of ammonia nitrogen and the processes of nitrogen transformation and transport in vadose zone.The flow rate of inflow during the infiltration experiment was 3888 mL/d.Under alternative leaching and drying conditions,the column was totally recharged 23894 L of simulated reused water with 5 mg/L of ammonia nitrogen in 136 days.The research shows that biological nitrogen removal is the main way to remove nitrogen of reused water for groundwater recharge,which makes full use of the aerobic,anaerobic and anoxic environment of unsaturated zone.The mechanism of removing ammonia nitrogen in vadose zone is the absorption of soil particle and biodegradation.The concentration of nitrate-N（including nitrite-N） in the water recharged to saturated zone is obviously increased in an early period of recharging with reused water after a drying period.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2010年第6期52-58,共7页
Earth Science Frontiers
基金
国家高技术研究发展计划(2007AA06Z337)
国家自然科学基金项目(40772155)
关键词
氨氮
包气带
干湿交替
再生水
ammonia nitrogen
vadose zone
alternative leaching and drying
reused water
