Both the nitrification and denitrification performance decreased obviously, although the nitrate removal in the first anoxic zone was increased when the value of R was higher than 1.0.

• 结果表明，当R值高于1.；0时，尽管第一段缺氧区的硝酸盐氮去除量明显增加，而系统硝化、反硝化效果均明显降低。