Integrated study of chemical, hydrological and biological aspects of impaired rivers to support restoration strategies

The human presence and activities affect the environmental quality of water bodies in different ways. Pressures concern various aspects of the overall environmental quality and their effects are cumulative and synergic. That’s why an integrated approach is needed to understand and assess the importance of each kind of stressors and to define restoration strategies. The research work carried out in the last three years and shown in this thesis concerns impaired river ecosystems and includes, in particular: 1) Integrated study of chemical, hydrological and biological aspects of impaired rivers, especially those affected by multiple alterations in urban environments and, thus, wastewater treatment plant effluent dominated. A case study (Lura stream) is presented. 2) Development of analytical methods for determining organic micropollutants (PAHs, triazines and their main transformation products) in a wide range of surface and wastewater samples (coming from different environments in Italy and Spain) and, consequently, for evaluating the contamination from wastewater treatment plant discharges. 3) Evaluation of the organic micropollutant removal efficiencies of wastewater treatment plants and comparison of the concentrations measured in effluent samples to the environmental quality objectives fixed for surface waters, as most of the receptor flow is made by the discharged effluent itself. 4) Study of the performance of a demonstration scale constructed wetland in removing inorganic and organic contamination from wastewater treatment plant effluents, as a possible strategy for impaired river restoration.