BUSCADOR RECOLECTA

As normal municipal wastewater treatment plants (MWTP) are not able to entirely degrade xenobiotic substances, this study focuses on modified solar photo-Fenton treatment (5 mg L−1 Fe, initial pH ≈ 7) of a municipal wastewater treatment plant (MWTP) effluent. However, effluents do not contain compounds which could form photoactive Fe3+ complexes. The use of ferrioxalate, humic substances (HA) and mixing the MWTP effluent with small amounts of influent could be justified to form photoactive Fe3+ complexes. All experiments were done in MWTP effluent spiked (5 or 100 μg/L) with 15 emerging contaminants (ECs) using a pilot compound parabolic collector (CPC) solar plant designed for solar photocatalytic applications. Dissolved organic carbon and UPLC–UV (with prior solid phase extraction) were applied for evaluating the results. The oxalate-enhanced process provided satisfactory EC degradation results but low residual pH of the treated water. HA (10 mg L−1) enhanced the process, balancing degradation time and residual pH. Mixing of MWTP influent and effluent delivered rather disappointing results, as EC degradation was unsuccessful in all cases tested.

Modern water policy requires new kinds of economic information in order to improve the ability of stakeholders and water authorities to analyze the whole set of alternatives available, to provide transparency and to assess and adapt water decisions to the emerging water management challenges. Considering this, we present an overview of the main drivers of economic information in the European water policy agenda as defined by the Water Framework Directive. After a brief introduction, the paper explains how basic economic statistics have been used to carry out the economic analysis of water use for the preparation of river basin management plans. We present the strategies used to enhance the usefulness of the economic information already available. The paper ends with a reflection on what parts of the economic information gaps have been satisfactorily dealt with and what the remaining gaps are.

In semiarid regions, reclaimed water can be an important source of emerging pollutants in groundwater. In Gran Canaria Island, reclaimed water irrigation has been practiced for over thirty years and currently represents 8% of water resources. The aim of this study was to monitor contaminants of emerging concern and priority substances (2008/105/EC) in a volcanic aquifer in the NE of Gran Canaria where the Bandama Golf Course has been sprinkled with reclaimed water since 1976. Reclaimed water and groundwater were monitoring quarterly from July 2009 to May 2010. Only 43% of the 183 pollutants analysed were detected: 42 pharmaceuticals, 20 pesticides, 12 polyaromatic hydrocarbons, 2 volatile organic compounds and 2 flame retardants. The most frequent compounds were caffeine, nicotine, chlorpyrifos ethyl, fluorene, phenanthrene and pyrene. Concentrations were always below 50 ng L− 1, although some pharmaceuticals and one pesticide, cholrpyrifos ethyl, were occasionally detected at higher concentrations. This priority substance for surface water exceeded the maximum threshold (0.1 μg L− 1) for pesticide concentration in groundwater (2006/118/EC). Sorption and degradation processes in soil account for more compounds being detected in reclaimed water than in groundwater, and that some contaminants were always detected in reclaimed water, but never in groundwater (flufenamic acid, propyphenazone, terbutryn and diazinon). Furthermore, erythromycin was always detected in reclaimed water (exceeding occasionally 0.1 μg L− 1), and was detected only once in groundwater. In contrast, some compounds (phenylephrine, nifuroxazide and miconazole) never detected in reclaimed water, were always detected in groundwater. This fact and the same concentration range detected for the groups, regardless of the water origin, indicated alternative contaminant sources (septic tanks, agricultural practices and sewerage breaks). The widespread detection of high adsorption potential compounds, and the independence of concentration with origin and depths, indicates the existence of preferential flows phenomena as potential contamination route in volcanic fractured materials.

The Azuaje travertines in the north of Gran Canary Island crop out in the Azuaje Gorge, which is incised into Miocene volcanic breccias of the Roque Nublo Formation. This travertine is interesting because of the scarcity of travertines in the Canary Islands and its close relationship with recent volcanic events. Part of the travertine overlies a lava flow, dated at 2420 ± 40 years BP. The travertine is composed mainly of aragonite in both perched systems on the gorge walls and in gorge bottom deposits parallel to the present stream. Perched systems include deposits from the feeder conduits within the Roque Nublo Formation that spilled out through waterfalls and over barriers. The gorge (valley) bottom system includes barrier and pool deposits. The main laminated facies are composed mostly of large fibrous aragonite crystals, while there are also common micritic and porous microfabrics. Shrubs, coated grains, coated bubbles and rafts are present in many of the deposits. Detailed study of the microfacies shows the presence of sparsely distributed biogenic features. The δ13C values are between + 4.0 and + 11.0‰, and the δ18O values range between − 11.0 and − 2.0‰ VPDB. These δ13C values lie within the range of those of thermogene travertines fed by thermal waters that cooled downstream, as indicated by the increase of the carbon and oxygen isotope values in that direction. The common occurrence of fibrous radial fabrics is interpreted to be due to disequilibrium conditions during aragonite precipitation. Disequilibrium was likely caused by rapid CO2 degassing of the thermal waters that led to a rapid increase in the degree of aragonite saturation. Thus, the morphology of the aragonite crystals and the isotopic composition indicate that the formation of the Azuaje travertine was mostly due to abiogenic processes induced by rapid degassing of thermal waters, linked to the presence of a recent lava flow within the Gorge. In short, the Azuaje travertine shows the important role of volcanic activity in travertine deposition, in the facies distribution as well as in the geochemical signatures of the deposits, and so can be used as a recent analogue for ancient travertine deposits in volcanic settings.

A simple method using direct sample injection combined with liquid chromatography tandem mass spectrometry has been developed for the simultaneous analysis of six alkaloid compounds in environmental samples. The target list includes two psychostimulants (nicotine and caffeine), three metabolites (cotinine, nicotinic acid and paraxanthine) and a coffee chemical (trigonelline). The analytical method was evaluated in three different matrices (surface water, influent and effluent wastewater). The method developed showed an adequate sensitivity, below 0.6 μg L(-1) for wastewater and 0.1 μg L(-1) for river matrices, without any prior treatment of the samples. Finally, the methodology was applied to real samples for evaluation of their removal from a sewage treatment plant and their persistence/fate in the aquatic environment. All compounds studied in this work were detected at all sampling points collected along the Henares River. However, nicotinic acid was only detected three times in treated sewage samples at levels above its detection limit.