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Ricart M.,Catalan Institute for Water Research | Ricart M.,University of Girona | Guasch H.,University of Girona | Alberch M.,Empresa Mixta dAigues de la Costa Brava S.A. | And 14 more authors.
Aquatic Toxicology | Year: 2010

Triclosan is a commonly used bactericide that survives several degradation steps in WWTP (wastewater treatment plants) and potentially reaches fluvial ecosystems. In Mediterranean areas, where water scarcity results in low dilution capacity, the potential environmental risk of triclosan is high. A set of experimental channels was used to examine the short-term effects of triclosan (from 0.05 to 500 μgL -1) on biofilm algae and bacteria. Environmentally relevant concentrations of triclosan caused an increase of bacterial mortality with a no effect concentration (NEC) of 0.21 μgL -1. Dead bacteria accounted for up to 85% of the total bacterial population at the highest concentration tested. The toxicity of triclosan was higher for bacteria than algae. Photosynthetic efficiency was inhibited with increasing triclosan concentrations (NEC = 0.42 μgL -1), and non-photochemical quenching mechanisms decreased. Diatom cell viability was also affected with increasing concentrations of triclosan. Algal toxicity may be a result of indirect effects on the biofilm toxicity, but the clear and progressive reduction observed in all the algal-related endpoints suggest the existence of direct effects of the bactericide. The toxicity detected on the co-occurring non-target components of the biofilm community, the capacity of triclosan to survive through WWTP processes and the low dilution capacity that characterizes Mediterranean systems extend the relevance of triclosan toxicity beyond bacteria in aquatic habitats. © 2010 Elsevier B.V. Source

Matamoros V.,University of Girona | Sala L.,Consorci de la Costa Brava | Salvado V.,University of Girona
Bioresource Technology | Year: 2012

The effect of hydraulic retention time (HRT), solar radiation and seasonality on the removal efficiency of 18 emerging contaminants has been studied in a biological filtration pilot plant based on Daphnia sp. The pilot plant consisted of a homogenization tank and two lines, A and B, each with four 1m 3 tanks. One of these lines was directly exposed to sunlight whereas the other line was covered. Our results suggest that biodegradation and photodegradation are the most important removal pathways, whereas sorption makes a minor contribution. The removal efficiency ranged from no detectable removal to more than 90%. The kinetics of the degradation process was fit to a first order kinetic, with half-lives from 0.6 to 42days, depending on the particular compound. However, a scaling effect comes into play as the pilot plant was found to be more efficient than a similar full-scale polishing pond. © 2011 Elsevier Ltd. Source

Pau C.,University of Girona | Serra T.,University of Girona | Colomer J.,University of Girona | Casamitjana X.,University of Girona | And 2 more authors.
Water Research | Year: 2013

A great challenge in water reuse is the reduction of suspended particle concentration in wastewater. In particular the reduction of the presence of small particles in suspension which cause a cloudy appearance in the water and, which also make disinfection difficult. The present study evaluates the filtering capacity of a population of Cladodera (Daphnia magna) in secondary effluents from a wastewater plant. The study was performed in both a mesocosm and the laboratory, in an effort to compare the grazing on sludge particles by Daphnia versus the settling rate of those sludge particles. The particle volume concentration of small particles (with a diameter below 30 μm) was used to evaluate the efficiency of the proposed biotreatment system for small particles. Both laboratory and mesocosm results showed that the suspended particle volume concentration decreased with time due to the Daphnia filtration, with the highest reduction in experiments carried out with the highest Daphnia concentration. In the mesocosm experiments, the Daphnia diameter was also found to play an important role, with an allometric relationship between the filtering rate of Daphnia and the Daphnia nondimensional diameter. In laboratory experiments, the effect of D. magna in the suspended concentration of small particles was in the range of 10.1-29.4%, according to the range of Daphnia concentration of 10-50 ind/l. For laboratory experiments, sedimentation was responsible for 62.2% of the suspended particle concentration reduction. For the mesocosm experiments, the reduction in the particle concentration attributed to the Daphnia filtration ranged between 2.5 and 39%, corresponding to Daphnia concentrations of between 5 and 100 ind/l (i.e. biovolumes of 8-60 ind/l). © 2012 Elsevier Ltd. Source

Margui E.,University of Girona | Iglesias M.,University of Girona | Camps F.,Mas Badia IRTA Agricultural Experimental Station | Sala L.,Consorci de la Costa Brava | Hidalgo M.,University of Girona
Environmental Science and Pollution Research | Year: 2016

The presence of potentially toxic elements (PTEs) may hinder a more widespread application of biosolids in agriculture. At present, the European Directive 86/278/CEE limit the total concentrations of seven metals (Cu, Cr, Ni, Pb, Zn, Cd and Hg) in agricultural soils and in sewage sludges used as fertilizers but it has not taken into consideration the potential impacts of other emerging micropollutants that may be present in the biosolids as well as their mobility. The aim of this study was to evaluate the accumulation and mobility of 13 elements (including regulated metals and other inorganic species) in agricultural soils repeatedly amended with biosolids for 15 years. Firstly, three digestions programs using different acid mixtures were tested to evaluate the most accurate and efficient method for analysis of soil and sludge. Results demonstrated that sewage sludge application increased concentrations of Pb and Hg in soil, but values did not exceed the quality standard established by legislation. In addition, other elements (As, Co, Sb, Ag, Se and Mn) that at present are not regulated by the Spanish and European directives were identified in the sewage sludge, and significant differences were found between Ag content in soils amended with biosolids in comparison with control soils. This fact can be related to the increasing use of silver nanoparticles in consumer products due to their antibacterial properties. Results from the leaching tests show up that, in general, the mobility degree for both regulated and non-regulated elements in soils amended with biosolids was quite low (<10 %). © 2015, Springer-Verlag Berlin Heidelberg. Source

Garcia-Lledo A.,University of Girona | Ruiz-Rueda O.,University of Girona | Vilar-Sanz A.,University of Girona | Sala L.,Consorci de la Costa Brava | Baneras L.,University of Girona
Ecological Engineering | Year: 2011

Vegetation coverage is considered to be a key factor controlling nitrogen removal in wetlands. We describe the use of newly designed stainless steel incubation chambers to detect shifts in the in situ nitrate reduction activities associated to areas covered with common reed (Phragmites australis) and cattail (Typha latifolia) in the sediment of a free water surface constructed wetland (FWS-CW). Activities were measured at six different positions and times of the year and were related to physicochemical and hydraulic variables. Mean nitrate+nitrite reduction activities varied from 11.1 to 69.4mgN/m2/h and showed a high variability within sediment types. Ammonification rates accounted for roughly 10% of the total nitrate reduction and were especially relevant in vegetated areas. Measured activities were highly above total nitrogen removal efficiencies estimated in the three parallel treatment cells of the Empuriabrava FWS-CW, indicating the potentiality of the system. In situ nitrate reduction activities correlated well with physichochemical characteristics such as pH and temperature. Additionally, differences in the total nitrogen removal efficiencies were detected between the three treatment cells and were related to changes in the water retention time. The plant species effect was detected in treatment cells of comparable hydraulic loads in which vegetation belts dominated by Typha latifolia were shown to have greater nitrogen removal efficiencies. © 2010 Elsevier B.V. Source

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