Fifteen-year study of environmental dredging effect on variation of nitrogen and phosphorus exchange across the sediment-water interface of an urban lake
Fifteen-year study of environmental dredging effect on variation of nitrogen and phosphorus exchange across the sediment-water interface of an urban lake
复制标题
DOI：
10.1016/j.envpol.2016.06.040
复制
发表时间：
2016-12-01
影响因子：
8.9
通讯作者：
Fan, Chengxin
中科院分区：
文献类型：
--
作者：
Liu, Cheng;Zhong, Jicheng;Fan, Chengxin
环境疏浚已广泛应用于中国湖泊，以减少其内部营养负荷。然而，疏浚对减少氮（N）和磷（P）的内部负荷和改善水质的效果受到一些研究人员的质疑。在这项研究中，长期（类似15年）疏浚，以减少内部N和P负荷在一个封闭的，污染的城市湖泊的影响进行了调查。结果表明，疏浚后水体中可溶性活性磷（SRP）的释放迅速受到抑制，疏浚效果可持续18个月左右。疏浚后2-8个月内NH_4 ~+-N释放量显著增加，此后21-32个月内NH_4 ~+-N释放量维持在较低水平。外源污染负荷的持续输入导致了SRP和NH 4 +-N释放速率的增加。因此，疏浚后三年的外部污染负荷减少，以加强修复效果。此后约六年的夏季，沉积物中NH 4 +-N和SRP的扩散通量均较高，随后呈下降趋势。外负荷降低后，上覆水中NH 4 +-N浓度降低，但夏季上覆水中SRP浓度仍较高。第二，中期（
Environmental dredging has been applied widely in Chinese lakes to reduce their internal nutrient loads. However, the efficacy of dredging to reduce internal loading of nitrogen (N) and phosphorus (P) and to improve water quality has been questioned by some researchers. In this study, the long-term (similar to 15 years) effects of dredging to reduce internal N and P loading in a closed, polluted urban lake were investigated. The results showed that the release of soluble reactive phosphorus (SRP) could be suppressed quickly after dredging, and that the dredging effect was sustained for about 18 months. A significant release of NH4+-N was discovered during the first 2-8 months after dredging, followed by maintenance of low-level release rates for about 21-32 months. The continuous inflowing of external pollution loading led to the increase in the release rates of SRP and NH4+-N. The external pollution loading was therefore reduced three years after dredging to strengthen the remediation effect. After that, high diffusive flux from the sediment was observed for both NH4+-N and SRP during summer seasons for about six years, followed by a decreasing trend. The NH4+-N concentration in the overlying water was reduced after the reduction of external loading, while a high concentration of SRP in the overlying water was still observed during summer seasons. In conclusion, the mid-term (