净水厂污泥覆盖控制底泥氮磷释放效果

室内静态模拟净水厂污泥与沙、沸石、锁磷剂(镧改性膨润土Phoslock^?)等4种覆盖材料控制底泥氮磷的释放效果.结果表明:在覆盖强度为2 kg·m^-2条件下,与对照组相比,沸石覆盖对氨氮的平均削减率为42.04%,沙覆盖和锁磷剂覆盖对氨氮均没有削减效果,净水厂污泥覆盖不仅对氨氮没有削减效果,而且还会向水体释放氨氮;锁磷剂、净水厂污泥、沸石和沙的覆盖对正磷酸盐的平均削减率分别为75.98%,53.73%,28.09%和10.69%.最后,分析几种覆盖材料

Efficiency of Controlling Nitrogen and Phosphorus Release From Sediment Using Thin-Layer Capping With Water Treatment Plant Sludge

The efficiency of controlling nitrogen and phosphorus release from sediment using four capping materials(including water treatment plant sludge, sand, natural zeolite and lanthanum-modified bentonite)were evaluated through sediment incubation laboratory experiments lasted for 35 days. The results showed that, under the condition of dose rate 2 kg·m^-2, the average reduction efficiency of ammonia nitrogen in overlying water by zeolite capping was 42.04%, and there was no obvious effect on ammonia nitrogen reduction between sand capping and lanthanum-modified bentonite capping. More notably, water treatment plant sludge capping not only failed to control ammonia nitrogen release from sediment but also released ammonia nitrogen into overlying water. The average reduction efficiency of orthophosphate in overlying water using lanthanum-modified bentonite, water treatment plant sludge, zeolite and sand capping was 75.98%, 53.73%, 28.09% and 10.69%, respectively. Finally, the feasibility and difficulties were analyzed when the four capping materials were used, which indicates that the water treatment plant sludge is a feasible way for developing as a sediment capping material to control the nitrogen and phosphorus release from sediment.