垂直流人工湿地堵塞和轮休过程中水流变化规律  

Research on Variation Law of Flow Pattern during Clogging and Alternate Operation Processes in Vertical Flow Constructed Wetlands

作　　者：李曼[1] 华国芬[1] 姬雨雨 

机构地区：[1]河海大学水利水电学院,江苏南京210098

出　　处：《水处理技术》2017年第1期57-61,共5页Technology of Water Treatment

基　　金：江苏省自然科学基金(BK20130834);国家自然科学基金(51509070);博士后科学基金资助项目(2015M571779);中央高校基本科研业务费专项基金(2015B15214)

摘　　要：采用渗透系数的定量化方法分析了垂直流人工湿地堵塞全过程,以NaCl为示踪剂开展示踪试验,研究湿地堵塞和轮休过程中水流变化规律。结果表明:整个运行过程中,渗透系数的变化速率逐渐变缓(k1/k2=2,k是渗透系数的变化速率);轮休措施对表层渗透系数的缓解速率是中下层的10倍;不同堵塞程度对湿地内部水流流场的扰动时间不同。比较而言,堵塞前期水流的不均匀性主要表现在投加示踪剂的前400 min,堵塞后期是在加示踪剂后的400min后;轮休过后示踪剂浓度波动变小,内部水流的"回混"现象得到缓解。水流散度变化规律表现为堵塞前期水流更接近活塞流,反应效率最高;堵塞后期水流混合程度最强;轮休措施在一定程度上能够缓解湿地内部水流的分散程度,提高反应效率。The whole clogging process was quantitatively analyzed with hydraulic conductivity. The NaCl tracer tests were carried out to investigate the variation law of flow during the clogging and resting processes. The results showed that the change rates of hydraulic conductivity became gradually slow with the operation time. Alternate operation release could alleviate surface hydraulic conductivity was about ten times of that in middle and lower layer. The disturbance time of the flow field was different under different clogging degree. The non-uniformity of the water flow was mainly shown in the first 400 minutes after adding the tracer in the early clogging stage, while in the later clogging stage, it was shown in the later 400 minutes. Tracer concentration fluctuations became smaller, internal flow ＂back-mixing＂ was alleviated aftar altemate operation release process. The variation of the water flow divergence was more close to the piston flow and the reaction efficiency was highest in the early stage of the clogging. In the later clogging, the flow mixing was strongest. Alternate operation release could alleviate the dispersion of internal flow in a certain extent and improve the reaction efficiency.

关 键 词：垂直流人工湿地 堵塞 水流流态 示踪试验 轮休 

分 类 号：X791[环境科学与工程—环境工程]