傍河型水源井氨氮阻断与去除工程设计案例分析

Remediation and interception of riverside water wells contaminated by ammonium-nitrogen: An engineering case study

针对沈阳市傍河型水源地的氨氮(NH+4-N)污染问题,通过野外研究区的水文地质调查,在查明研究区NH+4-N污染特征的基础上,结合室内批试验、柱实验和数值模拟,筛选出最佳的NH+4-N去除方案,提出了研究区渗透反应格栅(PRB)构建方案,并成功构建了示范工程尺度的PRB,用以去除地下水中的NH+4-N污染.室内批实验和柱实验表明,利用微生物硝化作用结合沸石的吸附作用去除地下水中NH+4-N是可行的.通过对研究区水质数值模拟,发现构建有一定弧度的PRB能最大限度的保护水源井.在PRB的构建过程中,利用高压旋喷技术和旋挖技术解决了大深度(>30 m)PRB的构建问题,且PRB建成运行监测表明,示范工程尺度的PRB能有效阻断和去除地下水中NH+4-N.

Aiming at the ammonium-nitrogen（ NH＋4-N） contamination problems in the riverside groundwater source field of Shenyang,based on the batch tests,column experiments,Visual Modflow simulation,and field hydrogeological investigation,a permeable reactive barrier（ PRB） was designed to remediate NH＋4-N. The design and construction of the PRB was successfully conducted. The batch and column experiments showed that the combination of zeolite adsorption and biological nitrification to remove NH＋4-N was feasible. The Visual Modflow simulation found that compared with a straight PRB,a PRB with angles was better in protecting the water wells. In the PRB construction process,the high pressure jet grouting technology and rotary drilling technology were applied to solve the problem of PRB construction depth（ 30 m）. According to the data collected from the PRB,the demonstration project successfully achieved the ideal removal and interception of NH＋4-N in the riverside source field.