摘要
我国水环境污染日趋严重,传统人工湿地复氧量常小于截留污染物降解需氧量,床体氧环境较差直接影响污水处理效率,且易于堵塞。本研究以探索新型潮汐流人工湿地对污水的高效处理为目的,以室内无植物封闭柱式潮汐湿地床为研究对象,探讨5种不同运行条件下污染物去除能力和复氧效果。结果表明:不同运行条件对悬浮物的去除率影响不大,淹水时间3h,总磷(TP)和氨氮(NH3-N)的去除效果最优,且采用一级反应动力学计算得到的有机物降解常数KBOD最大,有机物降解能力较强。通过对各运行条件系统供氧和理论污染物降解需氧的恒量计算发现,在忽略植物根系泌氧和大气自由扩散复氧的前提下,排空时间3h均满足系统污染物理论需氧量的需求。不同运行条件床体基质孔隙率差别不明显,有机负荷是影响孔隙率变化的主导因素,适当轮休可有效缓解堵塞现象发生,恢复床体水流传导力。
The water environment is facing an increasing threat recently and the oxygen supply in traditional constructed wetlands is much more less than oxygen consumption by pollutants degradation,which affects the system performance and causes more clogging happened.The tidal flow constructed wetland has a good performance with its novel operation design.This study is based on the lab-scale tidal flow constructed wetland to discuss the performance under five operation conditions.The results showed that the TSS removal efficiency was not affected under five operation conditions significantly but TP and NH3-N showed good performance under 3 h saturated time operating condition.After calculation by first-order kinetics,the highest KBOD value under this operation also indicated its strong organic matter degradation ability.With the hypothesis of no oxygen released from plant root and no exchanged from air to water,the oxygen drew into the bed during 3 h drain period was enough for pollutants removal.The matrix porosity did not have regular change with different operations,but the organic matter loading rates make a main contribution for the porosity change and a suitable bed rest could improve the water conductivity and relieved the clogging happen.
出处
《中国农业大学学报》
CAS
CSCD
北大核心
2010年第2期106-113,共8页
Journal of China Agricultural University
基金
科技部农业科技成果转化资金项目(2007GB23600460)
关键词
污水处理
潮汐流人工湿地
复氧能力
污染物去除
wastewater treatment
tidal flow constructed wetland
oxygen supply
pollutant removal
