Optimal flow for brown trout: Habitat - prey optimization.

The correct definition of ecosystem needs is essential in order to guide policy and management strategies to optimize the increasing use of freshwater by human activities. Commonly, the assessment of the optimal or minimum flow rates needed to preserve ecosystem functionality has been done by habitat-based models that define a relationship between in-stream flow and habitat availability for various species of fish. We propose a new approach for the identification of optimal flows using the limiting factor approach and the evaluation of basic ecological relationships, considering the appropriate spatial scale for different organisms.

COD, nutrient removal and disinfection efficiency of a combined subsurface and surface flow constructed wetland: A case study.

A constructed wetland system composed of a subsurface flow wetland, a surface flow wetland and a facultative pond was studied from July 2008 until May 2012. It was created to treat the domestic sewage produced by a hamlet of 150 inhabitants. Monthly physicochemical and microbiological analyses were carried out in order to evaluate the removal efficiency of each stage of the process and of the total treatment system.

Simultaneous determination of triazines and their main transformation products in surface and urban wastewater by ultra-high-pressure liquid chromatography-tandem mass spectrometry.

This work describes the optimization, validation and application of an ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the quantification and confirmation of 11 compounds (atrazine, simazine, terbuthylazine, terbumeton, terbutryn and their main transformation products) in surface and wastewater samples. Several of these analytes are included in the list of priority substances in the framework on European Water Policy. The application of this method to water samples reveals that the most relevant transformation products (TPs) should be incorporated into current analytical methods to obtain a more realistic knowledge of water quality regarding pesticide contamination.