Candela Angela, Freni Gabriele, Mannina Giorgio, Viviani Gaspare
Dipartimento di Ingegneria Idraulica e Applicazioni Ambientali, University of Palermo, 90128 Palermo, Italy.
Water Sci Technol. 2009;59(11):2125-35. doi: 10.2166/wst.2009.882.
In this study, diffuse and point source pollutant loads were evaluated using an Italian case study: the Nocella catchment, which has been subject to extensive monitoring. The Nocella catchment is located in Sicily (Italy) and has an area of about 60 km(2). The river receives wastewater and stormwater from two urban areas drained by combined sewers. The two sewer systems, two wastewater treatment plants and a river reach were monitored during both dry and wet weather periods. Thereafter, an integrated catchment-scale model was applied to simulate point pollutant sources, i.e., pollution coming from the urban drainage system, and nonpoint pollutant sources, i.e., pollution coming from agricultural and wildlife activities. Different models were combined and long-term simulations were carried out in order to reconstruct the total pollutant loads discharged into the receiving water body and identify the roles of the different pollutant sources. This study demonstrates the complexity of water quality assessment in partially urbanised natural basins where neither point nor nonpoint sources can be neglected. Point sources are mainly responsible for acute oxygen demanding polluting impact during wet weather periods, and both point and nonpoint sources are responsible for the impact of nutrients on the receiving water body.
在本研究中，利用意大利的一个案例研究——诺切拉流域对扩散源和点源污染物负荷进行了评估，该流域已进行了广泛监测。诺切拉流域位于意大利西西里岛，面积约60平方公里。该河流接收来自两个由合流制下水道排水的城市区域的废水和雨水。在旱季和雨季期间，对两个下水道系统、两个污水处理厂和一段河流进行了监测。此后，应用一个综合的流域尺度模型来模拟点源污染物，即来自城市排水系统的污染，以及非点源污染物，即来自农业和野生动物活动的污染。将不同模型进行组合并进行长期模拟，以重建排入受纳水体的总污染物负荷，并确定不同污染物源的作用。本研究表明，在部分城市化的自然流域中，水质评估具有复杂性，其中点源和非点源均不可忽视。点源主要导致雨季期间对需氧量的急性污染影响，而点源和非点源均对受纳水体中的营养物质影响负责。
