人工快速渗滤系统堵塞-恢复实验研究

Experimental study on blockage and recovery of constructed rapid infiltration system

采用干湿交替间歇进水的运行方式,以不同粒径的河砂为填料构建3组人工快速渗滤(CRI)系统,研究CRI系统的堵塞-恢复规律,填料粒径与系统出水COD、水力负荷和纳污量之间的关系,以及环境温度对系统处理效率的影响。结果表明,CRI系统堵塞后经过一段时间的恢复期即可以自然恢复活性。细砂CRI系统的稳定性最好,出水COD最稳定,抗冲击能力和纳污量强于混砂和粗砂CRI系统。当温度在适宜微生物生长的范围内波动时,对系统处理效率的影响并不明显。实际工程应建造多级系统或并行系统解决堵塞问题,以保证系统的水力负荷和稳定运行。

A laboratory experiment of constructed rapid infiltration （CRI） system that constructed by 3 types grain size of filler composed by natural sands was performed to investigate the blockage and recovery of the treatment system. The relationship between the grain size of filler and the drainage quality, the hydraulic loading and the pollu- tants capacity of the system was studied, and the influence of environmental temperature on the treatment efficiency was investigated. Results indicated stop running when the CRI system became blockage, it could be recovered natu- rally. The CRI system constructed by fine sands （grain size ranged from 0.9 mm to 2.0 ram） presented best stability with stable effluent COD. The resistant ability and the pollutants capacity of fine sands CRI system were stronger than that of system constructed by mixing sands and coarse sands. When the environmental temperature fluctuated in the range that suitable for microbial growth, it would have little influence on the treatment efficiency of the CRI sys- tem. The actual project of CRI system should be built as multi-level systems or parallel systems to solve the problem of blockage, and further then improve the hydraulic loading and the running stability of CRI system.