| The removal of nitrogen was studied in four types of pilot-scale rivers. The embankment for rivers No. 1, 2 and 3 consisted of respectively spheriform ecological-concrete prefab-bricks, rectangular ecological-concrete prefab-bricks and square ecological-concrete prefab-bricks with 4 hemispheroids. The embankment for river No. 4 was made of concrete C25. The results show that the removal rates of NH＋4-N, NO-2-N, NO-3-N and TN of river 1 are 83.6%, 75.2%, 37.1% and 47.5% under hydraulic retention time of 2 days, 83.4%, 53.0%, 30.6% and 40.4% for river 2, 88.1%, 72.4%, 33.0% and 40.9% for river 3.Under the same condition, NH＋4-N, TN of river 4 decreases by 61.1%, 9.1%,while NO-2-N, NO-3-N increase by 7.4%,3.4% due to the transformation of NH＋4-N. It indicates that ecological embankment rivers can effectively remove nitrogen. Besides, the addition of pore rate in embankment structure and more rate of plant coverage are good for the removal of nitrogen in ecological embankment rivers. |
