生态围隔对水源地水质的改善效果

Improvement of Ecological Enclosure on Water Quality in Drinking Water Source

采用渔网及土工布挂片双层材料以及填充的水花生构建了生态围隔,对藻类进行拦截,降低取水口藻类密度,同时通过水花生的吸收和拦截,以及土工布挂片形成的附着生物群落的降解和吸收作用,降低颗粒态以及溶解态营养盐,达到取水口水质的改善效果。生态工程实施后,取水口内悬浮颗粒物显著降低了29.8%,同时透明度提高了27.5%。对藻类的拦截效果研究表明,围隔对叶绿素a的去除率为23.0%,对总藻类数量的去除率为20.7%。通过对围隔内外蓝藻数量在藻类数量的比例分析,生态围隔对蓝藻的去除率高于总藻类的去除率,说明了对于藻类拦截的效果具有一定的选择性。对营养盐的改善效果主要体现在颗粒态物质上,其中颗粒态氮磷的去除率分别为48.4%和31.3%。

Fishing net and geotextile, together with the Ahernanthera philoxeroides, named as the compos- ite ecological enclosure, was constructed in drinking water source to intercept the algea and decrease the algea density within water source. The water quality was also improved by the absorption and interception by Alternan- thera philoxeroides and the degradation by biofilms attached on the encloure media. As the enclosure constructed, the average suspended particulate content was decreased by 29.8 %, and the water transparency （Secchi depth） was improved by 27.5%. The algea interception effect showed the chlorophyll a was removed by 23.0%, as well as 20.7% for total algea density. By analysis of the composition of algea colony, the blue - green algea was more effectively intercepted than total algea, which means the selective removel effect on the algea interception. The improvement effects on nutrients removel were mainly on particulate matter. The removel efficiency of particulate nitrogen and phosphorus was 48.4% and 31.3%, respectively.