中文摘要：

滤料级配是保证过滤效果的关键因素,讨论了在相同的L/d的情况下,滤料粒径及滤层高度对滤池出水效果的影响.实验结果表明,在L/d=1 300时,粒径及高度较小的滤柱处理效果好于粒径及高度较大的滤柱,但是粒径及高度较小的滤柱水头损失增加较快;预氧化可以明显改善过滤效果.在设计双层滤料滤池时,应从工程和经济角度同时出发,并结合滤前水质特点,优化出一个最佳L/d值.

英文摘要：

The grading of filter material is the key factor to guarantee the filtration effect.The influences of granule diameter of the filtrating media and the height of filter under the same ratio of the depth of filtration layer L to granule sized（L/d） is discussed in this paper.The results indicate that the treatment effect of filter with smaller granule size and layer height is better than the bigger one,when L/d ratio is 1 300.However,the head loss of the smaller filter increased faster.The pro-oxidation could improve filtration effect obviously.Both engineering and economy should be considered to optimize a L/d value,combining with the water quality before filtration,when a dual media filter is designed.