低温条件下不同面积浮岛对N、P的净化效果

人工浮岛作为有效净化富营养化水体的生态技术之一,现已得到广泛应用.然而浮岛面积的优化配置及其引发的二次污染问题仍需进一步深入探讨.研究以重庆彩云湖水库为例,探究在低温条件下不同面积旱伞草浮岛对于水库中NH3-N、P的吸收、净化效用及二次污染效果,同时,针对彩云湖水库实际情况对人工浮岛的最适面积进行了初步探讨.结果表明,随着浮岛面积的增大,对于总体而言,旱伞草浮岛对N、P的吸收量分别由531和92 g增加至3 965 g和727 g; 旱伞草腐解所造成的N、P释放量由不足100 mg/d增加至600 mg/d以上,而浮岛对于水体NH3-N、P的总体净化效率分别由50.52%和15.88%明显下降直至负值;对于单位面积浮岛而言,其对于水体中N、P的吸收量及其对于NH3-N、P的净化效率与总体净化效率变化趋势一致;对于彩云湖水库而言,其最适浮岛面积为50~70 m2.

Effects of floating islands areas on nitrogen and phosphorous purification at low temperature

The artificial floating island, as one of the ecological technologies to purify the eutrophicated water bulk, has been widely used; yet the optimal configuration of a floating island and its secondary pollution to water remains far from fully discussed. In the current study, we took Chongqing Caiyun Lake Reservoir as a case to examine the diverse Cyperus alternifolius float island area effects on NH3-N and P absorption, purification, and the secondary pollution of floating island to the reservoir under low temperature condition. Meanwhile, the optimum area of the artificial floating island was also presented according to the actual condition of the reservoir. The results show that with the increase of float island area, the absorption amount of N and P per floating island increased from 531 to 3 965 g, 92 to 727 g, respectively. The emission of N and P came from less than 100 to 600 mg/d and the N, P purification efficiency both obviously decreased from 50.52% and 15.88% to negative value. The varying trends of absorption amount of N, P and the purification efficiency of NH3-N, P per unit of area were consistent with the total purification efficiency per floating island. The optimum area of Caiyun Lake Reservoir is 50—70 m2.