When pH was 6.65, filtration rate was 8m/h and Do was 6.5mg/L, there existed the function relation between ferrous ions concentration and filter bed depth.是什么意思_When pH was 6.65, filtration rate was 8m/h and Do was 6.5mg/L, there existed the function relation between ferrous ions concentration and filter bed depth.在线翻译_英语_读音_用法_例句