以河道水为原水的高速过滤过程及其性能分析

针对平原城市缓流河道普遍存在的季节性水质恶化问题，采用预氧化、微絮凝+高速过滤对天津市某缓流河道水体进行中试规模实验。结果表明，该处理技术具有处理周期长(>24 h)、过滤滤速高(平均为43.26 m·h-1)和出水效果好(出水水质优于地表水Ⅳ类水质标准)的特点。同时发现：单位面积滤柱的产水率呈“阶梯”下降趋势；高速过滤的堵塞特征曲线服从三次多项式分布；系统过滤历经增长期、稳定期和衰减期，其中增长期为3~4 h，稳定期约14 h，过滤系数λ为(0.020 1±0.001 3) cm-1(置信度P=95%)，其可作为系统基本属性的定量参数。

High-speed filtration process of urban river raw water and its performance analysis

This study focused on the seasonal water quality deterioration problem of urban slow-flow rivers in the plain cities. A pilot scale process of pre-oxidation and micro-flocculation-high-speed filtration was applied to purify the slow flow river water in Tianjin. The results showed that this process was characterized as long treatment cycles (>24 h),high filtration speeds (43.26 m·h-1 on average) and good effluent quality, being superior to the class IV standard according to environmental quality standard for surface water. Furthermore, the water production rate per unit area in the filter column showed a “stepwise” downward trend and the plugging characteristic curve of the high-speed filtration followed a third order polynomial distribution. The system included the growth period of 3 to 4 hours, the stable period of 14 hours and the decay period during filtration. The filtration coefficient λ was (0.020 1±0.001 3 ) cm?1 (confidence P=95%) in the stable period and it can be used as an essential quantitative parameter of the system.