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¿Dónde terminan los microplásticos procedentes de acolchados biodegradables en los suelos agrícolas?
No full textMuchos de los acolchados biodegradables no se eliminan completamente bajo condiciones ambientales, encontrándose partículas en el suelo después de su uso. Este estudio investiga la movilidad de fragmentos de tereftalato de adipato de polibutileno (PBAT) procedentes de acolchados biodegradables en el suelo a través de la escorrentía superficial y la infiltración del agua, considerando dos escenarios: suelo en barbecho y suelo cultivado con cebada. Para ello, se utilizaron seis mesocosmos de escorrentía e infiltración (2x1x0,5 m) con suelo natural, bajo condiciones ambientales reales. Se realizaron muestreos periódicos de agua y también de suelo después de la cosecha. Los fragmentos de PBAT se identificaron y cuantificaron mediante microscopia infrarroja (μFTIR). Los resultados indican que >65% de los microplásticos (MP) permanecen en el suelo. La presencia de cebada disminuye su movilidad por escorrentía. La infiltración de MP es mínima, detectándose menos del 1% del total de MP entre 25-30 cm de profundidad
Chapter 14 - Modular and transportable constructed wetlands
No full textConstructed wetlands (CWs) were widely used to effectively remove contaminants from wastewater, while offering benefits for ecological value and landscape services. However, one limited factor for their practical applications lies in the conventional construction style, which is a laborious and complex civil engineering. As such, an idea of modular CW (MCW) was proposed, and embodiment was made for different scales of CW projects. This chapter introduces the MCW concept and the efforts made to realize it. MCW is a revolutionary approach and represents a paradigm shift from traditional CWs, offering a prefabricated, modular solution that simplifies the complexities of civil engineering in wastewater management. These prefabricated modular structures, assembled off-site and installed on-site, provide a streamlined, flexible, and user-friendly alternative to conventional CWs
Photoelectroheterotrophic production of polyhydroxybutyrate in purple phototrophic bacteria using a microbial electrochemical moving bed reactor
No full textDue to its metabolic versatility, mixed communities of purple phototrophic bacteria could be exploited for production of added value products using an electrode as electron donor. Indeed, microbial electrosynthesis has already been proved as a suitable strategy for polyhydroxybutyrate production under photoautotrophic conditions. In contrast with classical biofilm-based electromicrobiology studies, fluid-like electrodes can tune planktonic microbial metabolism to enhance biodegradation rates in brewery wastewater. In this work we have explored polyhydroxybutyrate production in a mixed community enriched from brewery wastewater using a photo-microbial electrochemical moving bed reactor (photoME-MBR). The bioelectrochemical reactor was operated under cathodic conditions (−0.8 V vs Ag/AgCl) with acetate as carbon source as a mean to evaluate i) PHB production and ii) bioelectrochemical performance. We observed how a cathodic polarization of the moving electrode played a key role on PHB production stimulating both direct microbial electron uptake from the conductive bed and electrochemically produced hydrogen in the vicinity of the current collector. Overall, the polarized reactor outperformed the non-polarized reactor by four-fold regarding PHB production rate. In addition, microbial communities analysis revealed Rhodopseudomonas sp. and Bradyrhizobium sp. as main genera in combination with other electroactive genera like Geosporobacter sp. This work revealed that cathodic moving beds could present a feasible platform for biorefineries and added value products production
A brief history of microplastics effect testing: Guidance and prospect
No full textNumerous reviews have consistently highlighted the shortcomings of studies evaluating the effects of microplastics (MP), with many of the issues identified in 2016 still relevant in 2024. Here, we summarize the current knowledge on MP effect testing, compare guidelines, and provide an overview of risk assessments conducted at both single species and community levels. We discuss standard test materials, MP characteristics, and mechanisms explaining effects. We have observed that the quality of MP effect studies is gradually improving, and knowledge on enhancing these studies is available. Recommendations include data rescaling and alignment for ecological risk assessment, with preference for using environmentally relevant MPs. A step-by-step protocol for creating polydisperse test materials is provided. Most risk assessments indicate that concentrations observed in ecosystems globally exceed the effect thresholds measured in the laboratory. However, using a higher-tier approach, no risks are expected for freshwater benthic communities at current MP exposure concentrations. Evidence on the mechanisms behind adverse effects is growing; however, more well-designed experiments are needed. A potential solution might involve comparing natural particles with MPs that are as similar in dimensions as possible, providing insight into the mechanisms of food dilution where volume is a critical determinant of toxicity
Human health risks associated to trace elements and metals in commercial fish from the Brazilian Amazon
No full textFish constitutes the main protein source for the Amazonian population. However, the impact of different anthropogenic activities on trace element and metal accumulation in fish and their risks for human health at a regional scale remain largely unexplored. Here we assessed exposure levels of 10 trace elements and metals (Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Pb, and Hg) in 56 samples belonging to 11 different species of fish from the Brazilian Amazon. We studied the relationship between exposure levels, fish origin, and fish feeding habits, and assessed toxicological and carcinogenic risks for the Amazonian population. No significant correlation was found between sampling site and exposure levels to the studied elements, but a significant difference was found between the accumulation of some metals and the position of the fish species in the food chain. The concentrations of Cr and Hg in fish flesh were found to exceed the Brazilian limits for human consumption. This study shows that current fish consumption patterns can lead to estimated daily intakes of Hg, As and Cr that exceed the oral reference dose, thus posing a toxicological concern. Furthermore, carcinogenic risks may be expected due to the continued exposure to Cr and As. The results of this study show that the consumption of wild caught fish in the Amazon region should be controlled. Moreover, continued monitoring of trace element and metal contamination in fish and on the health of the Amazonian population is recommended, particularly for riverine and indigenous communities
Water scarcity challenges water security: a case for Spain's freshwater ecosystems
No full textWater scarcity is an escalating environmental challenge, particularly in semi-arid regions like Spain, where balancing human and ecosystem needs is critical for sustainable development. Freshwater ecosystems are vital for biodiversity, water security, and economic systems, but often lose protection during droughts. Spain, largely under a Mediterranean climate, shows strong interdependence between ecological and socioeconomic systems, with agriculture, tourism, and energy sectors heavily reliant on scarce water resources. Spain's economy has thrived on water-dependent activities yet increasing droughts and infrastructure limits are pushing ecosystems toward collapse, with severe biodiversity loss and irreversible damage. Furthermore, investments aimed at increasing water-use efficiency often backfire, leading to expanded irrigation without real water savings. Climate change, urbanization, and pollution exacerbate these tensions, posing risks to public health and economic stability. Transformative strategies are urgently needed: protecting and restoring ecosystems, promoting conservation agriculture, regulating water-intensive industries, and planning collective responses to illegal water use. Simply increasing supply or reacting to crises without systemic change of water demands will not ensure future water security. Spain's experience highlights the urgent need for integrated management of natural and human systems to preserve freshwater resources, biodiversity, and economic resilience
A new application of K-means clustering analysis in hazard assessment of nitrate pollution in detrital aquifers
No full textGroundwater protection against anthropogenic pollution is an unavoidable task to ensure the sustainability of this important water resource. Evaluating pollution hazards through mapping is essential for aquifer protection. This research aims to delineate the hazard map of an anthropogenic contaminant (nitrate) in a detrital aquifer using K-means cluster analysis to eliminate some of the subjectivity of traditional methods have. Nitrate demonstrated to be a suitable indicator of anthropogenic pollution from nitrogen fertilisers used in crops, with a background threshold estimated at 14.9 mg/L using a probabilistic approach. Three levels of hazard were obtained. The highest hazard occurs to the south of study area, coinciding with the area with the highest recharge from irrigation returns. In these zones is not recommended groundwater for human consumption because the health risk. This demonstrates the strong influence of recharge on aquifer pollution risk. The results indicated that the K-means cluster map obtained a significant statistical correlation of 53% with nitrate concentrations in groundwater obtained from 23 sampling wells, which reliably validates the effectiveness of using this technique. This research shows the advantage of applying a novel data mining method to groundwater hazard assessment, providing a valuable tool for the adequate management and planning of groundwater resources
An Assessment of PM 2.5 Concentration from Traditional Heating in the Urban Households of Kashmir
No full textLeveraging insights into advanced oxidation processes for quaternary treatments
No full textThis study assesses the efficiency of ozonation, photocatalysis, and electrooxidation to treat the effluent from an urban WWTP spiked with a mixture of 17 cytostatic compounds at 25 μg/L. This concentration allowed us to
assess the efficiency of the different treatments, reaching good sensitivity for mass spectrometry detection avoiding sample treatments and study the kinetics when necessary. The presence of cytostatic drugs in urban
wastewater poses significant environmental and health concerns due to their toxicity and persistence. Conventional wastewater treatment plants (WWTPs) only remove part of these contaminants, being necessary to add additional processes. Ozonation with 200 mg O₃/L achieved over 90 % removal for ten compounds, while the removal of seven compounds was below 60 %. Photocatalysis with TiO₂ (500 mg/L) degraded four compounds by
over 90 %, but the removal of the other 13 compounds was below 75 %. Electroxidation was effective for
removing 14 out of the 17 compounds with an average global removal of 75 % and 94 % for eight compounds.
Results showed: i) single techniques do not achieve a high removal of all contaminants, ii) all compounds were
removed by at least one of the treatments, and iii) there is a fragmentation of knowledge, and most lab studies do
not predict the kinetic behavior of treatments of complex wastewater. The integration of multiple technologies
(e.g. electrooxidation and ozonation would be needed to enhance the overall removal efficiency of WWTPs and
accomplish stricter legislation. Further studies on potential challenges as by-product toxicity and energy consumption are necessary
