Presencia y evolución de microplásticos en estaciones depuradoras de aguas residuales de la Región de Murcia: propuesta de las mejores tecnologías disponibles para una emisión cero

[SPA] Las cifras mundiales de producción anual de plástico han sufrido un incremento del 2,5% durante el periodo 2018/19, siendo el sector del embalaje y empaquetado el mayor usuario de este producto. Estas cifras reflejan que los plásticos forman parte de nuestro día a día, aportando comodidad a nuestra forma de vida. Asimismo, y debido a la inadecuada gestión de residuos plásticos, a la lenta tasa de degradación de los mismos y al uso descontrolado de estos por parte del consumidor, los plásticos se han convertido en uno de los principales problemas medioambientales; problema que se agrava por la degradación de éstos en micropartículas, conocidas como microplásticos (MP). Los MP hacen referencia a plásticos con un tamaño menor de 5 mm; pudiéndose clasificar en MP primarios, fabricados intencionadamente con ese tamaño, y MP secundarios, procedentes de la continua fragmentación de plásticos de tamaño superior. Estos contaminantes emergentes se están encontrando en diversos entornos y su ingestión por los diferentes eslabones de la cadena trófica puede desencadenar problemas físicos y toxicológicos de gran importancia. Las plantas de tratamiento de aguas residuales, definidas como un conjunto de procesos físicos, biológicos y químicos, encargados de lograr un efluente de gran calidad, han sido consideradas fuente y sumidero de MP; siendo investigada, sobre todo en los últimos años, la concentración y la caracterización de estos en las aguas residuales. La presente Tesis Doctoral analiza la presencia y evolución de microplásticos en las EDAR Cabezo Beaza, Águilas, Mar Menor Sur y La Aljorra, sitas en la Región de Murcia. También, pretende añadir conocimiento sobre la eficiencia, en cuanto a la descarga de estos, de las distintas tecnologías presentes en las mismas. Para ello, las muestras de aguas residuales se filtraron al vacío y, cuando lo requerían, previamente separadas por densidad con una disolución de NaCl. La identificación se llevó a cabo con un estereomicroscopio trinocular y espectrometría infrarroja con transformada de Fourier. El porcentaje de retención de cada uno de los tratamientos estudiados fue de: 89,18% para el sistema de fangos activados convencional, 79,01% para el biorreactor de membranas, 75,49% para la filtración rápida de arena, 70,12% para el sistema de fangos activados con aireación prolongada y un 64,25% para el sistema de fangos activados con aireación prolongada, tipo carrusel. Pese a esto, estas EDAR son capaces de emitir entre 0,88·107 y 3,18·107 MP al día. La concentración media de MP fue superior en otoño, época señalada por fuertes lluvias en la Región, que favorecería el arrastre de MP hacia las depuradoras. Todas las tecnologías redujeron en más de un 90% las formas particuladas de los MP, pero no fibras, cuya retención mostró mayor dificultad. En cuanto al tamaño y al color, el 68,24% de los MP no superó el milímetro; y los tonos claros formados por el blanco y el beige (47,64%) y conocidos por favorecer la ingestión de MP, junto con el azul (30,45%) resultaron ser los más abundantes. El LDPE fue el polímero más encontrado en las EDAR (60,17%) debido, probablemente, a la actividad agrícola que las rodea y al uso incontrolado de las bolsas de plástico de un solo uso. A este le siguen el HDPE (11,15%) y el PP (10,62%), formando todos ellos parte de los plásticos más demandados en el mercado europeo. Finalmente, se analizaron las relaciones entre los MP y los parámetros físico-químicos de los procesos de depuración en la EDAR ECB, destacando que altos valores de sólidos en suspensión podrían favorecer la formación de heteroagregados con los MP, que sean menos solubles y de mayor velocidad de sedimentación. Además, se observó que valores de pH ácidos propician un tamaño menor del MP.[ENG] The global figures for annual plastic production have increased by 2.5% during the 2018/19 period, with packaging sector being the largest consumer of this product. These figures reflect that plastics are part of our daily life, providing comfort to our way of life. Likewise, and due to an inadequate management of plastic waste, a slow degradation rate and an uncontrolled use of plastic by general consumers, it has become one of the main environmental problems, aggravated by their degradation into microparticles, known as microplastics (MP). MP refer to plastics with a size smaller than 5 mm; being able to be classified in primary MP, intentionally released with that size, and secondary MP, coming from a continuous fragmentation of bigger plastics. These emerging pollutants have been isolated in different environments, and they accumulate through the food web, posing physical and toxicological problems. Wastewater treatment plants (WWTP), defined as a set of physical, biological and chemical processes, in charge of achieving a high quality effluent, have been considered a source and sink of MP; the concentration and characterization of these in wastewater being investigated, especially in recent years. This PhD analyzes the presence and evolution of microplastics in the WWTP “Cabezo Beaza”, “Águilas”, “Mar Menor Sur” and “La Aljorra” WWTPs, located in the Region of Murcia (Spain). It also aims to add knowledge about the removal efficiency of MP by different sewage treatment technologies. Wastewater samples were vacuum filtered and, when required, previously treated with a salt-saturated NaCl solution. Identification was carried out with a trinocular stereomicroscope and Fourier transform infrared spectrometry. The removal percentages were 89.18% for conventional activated sludge system, 79.01% for membrane bioreactor, 75.49% for rapid sand filtration, 70.12 % for activated sludge system with prolonged aeration, and 64.25% for a Carrousel oxidation ditch system. The daily emission factor ranged from 0.88 x 107 to 3.18 x 107 MP/d. The average MP concentration was higher in Autumn than in any other season, mainly because episodes of heavy rain during that season. All treatment technologies properly removed particulate forms of MP over 90%, although fibers were not that retained. Regarding size and color, 68.24% of MP did not exceed one millimeter, and white and beige MP (47.64%) were mainly isolated, together with blue ones (30.45%). The highest average concentration was by far due to low density polyethylene (60.17%), probably as a result of the proximity of WWTPs to crops within agriculture greenhouses, together with an excess use of single-use plastic bags. High density polyethylene (11.15%) and polypropylene (10.62%) were also isolated, both resin types demanded by plastic converters in Europe. Relationships between MP and the physicochemical parameters in wastewater samples from “Cabezo Beaza” WWTP were analyzed, highlighting that high suspended solids concentrations could enhance the formation of hetero-aggregates with MP, less soluble and of a higher sedimentation rate. In addition, low pH values lead to a statistically significant decrease on MP size.Fundación Séneca, Hidrogea, Centro Tecnológico de la Energía y el Medio Ambiente (CETENMA)Escuela Internacional de Doctorado de la Universidad Politécnica de CartagenaUniversidad Politécnica de CartagenaPrograma de Doctorado en Tecnología y Modelización en Ingeniería Civil, Minera y Ambienta

Weathering indices of microplastics along marine and coastal sediments from the harbor of Cartagena (Spain) and its adjoining urban beach

Marine and coastal sediments from the harbor of Cartagena (Spain) and its adjoining beach were investigated regarding their microplastic burden. Fibers accounted for 47.62% and 61.66% in marine and coastal sediments, respectively, followed by films (31.43% and 18.76%) and fragments (20.95% and 18.65%). Polyvinyl (36.07%), polypropylene (21.31%), and polyethylene (18.03%) were isolated for marine sediments, and low-density polyethylene (40.71%), polypropylene (20.16%), and acrylate (11.37%) for coastal sediments. Highest concentrations were found in the deepest marine sediments (24.0 m) and in the furthest zone from the seashore for coastal sediments (18 m). Carbonyl index increased in the intermediate area (12.5 m) for marine sediments (0.51), whilst vinyl index was maximum for the deepest samples (1.94), reporting Norrish type I and II reactions, respectively. Coastal sediments collected close to the high tide line displayed the highest average values for both indices, 1.57 and 1.29, respectively, indicating a higher exposition to weathering variables.We thank Pedro Martínez for technical assistance. This work was financially supported by grant 20268/FPI/17 from Fundación Séneca assigned to Dr. Sonia Olmos and by Project Number 5813/19IQA from Cartagena Port Authority

Commercial gilthead seabream (Sparus aurata L.) from the Mar Menor coastal lagoon as hotspots of microplastic accumulation in the digestive system

This paper presents the results on the presence and characterization of microplastics (MP) in the gastrointestinal tract of gilthead seabream (Sparus aurata L.), a species of commercial interest from the Mar Menor coastal lagoon in Southeast Spain. This is the first time that microplastic ingestion is recorded in any species from this semi-enclosed bay. Stomach and intestine from a total of 17 specimens captured by local fishermen were processed, and microplastic particles and fibers found in all of them were displayed. Overall, 40.32% (279/692) of total isolated microparticles proved to be microplastics; i.e., <5 mm, as identified by FTIR spectroscopy. The average value by fish was 20.11 _ 2.94 MP kg1, corresponding to average concentrations of 3912.06 _ 791.24 and 1562.17 _ 402.04 MP by kg stomach and intestine, respectively. Four MP forms were isolated: fiber (71.68%), fragment (21.15%), film (6.81%), and microbead (0.36%), with sizes ranging from 91 _m to 5 mm, an average of 0.83 _ 0.04 mm, and no statistically significant differences between mean sizes in stomach and intestine samples (F-test = 0.004; p = 0.936). Nine polymer types were detected, although most of fibers remained unidentified because of their small size, the presence of polymer additives, or closely adhered pollutants despite the oxidizing digestion carried out to eliminate organic matter. No significant correlation was found between main biological parameters and ingested microplastics, and high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene polypropylene (PEP), and polyvinyl (PV) were identified as the most abundant polymers. The average microplastic ingestion in this study area was higher than those reported in most studies within the Mediterranean Sea, and closely related to microplastic pollution in the surrounding area, although with a predominance of fiber form mainly due to fishery activities.This work was financed by Project 5345/18IQA (Technical University of Cartagena). Analyses carried out by Sonia Olmos were supported by a grant from Fundación Séneca (20268/FPI/17)

First evidence of microplastics isolated in European citizens’ lower airway

Microplastics (MPs) have been detected in all environmental locations, including the atmosphere. However, few studies have investigated the presence of airborne MPs in the human respiratory system. Our research purpose was to investigate these pollutants in the lower human airways of 44 adult European citizens, using bronchoalveolar lavage fluid (BALF) collection as a minimally invasive method, that enables the detection of these pollutants in living patients. We studied the relationship between the patients’ life habits and physiological parameters, based on background information and medical and occupational history, and the concentration of MPs isolated from their respiratory systems. Our results indicate that most MPs were in the form of microfibers (MFs) (97.06%), with an average concentration of 9.18 ± 2.45 items/100 mL BALF, and only 5.88% (0.57 ± 0.27 items/100 mL BALF) were particulate MPs, without a significant relationship with environmental, physiological, or clinical factors. The average size was 1.73 ± 0.15 mm, with the longest dimension (9.96 mm) corresponding to a polyacrylic fiber. Taken together, the results demonstrated the occurrence of MPs in the lower human airway, although more studies are necessary to elucidate the negative effects these pollutants could induce in the human respiratory system and its associated diseases.We wish to express our sincere appreciation to José V. Navarro for safe BALF samples transportation form HGUE to UPCT and back, as well as to the HGUE Pneumology Service, particularly to Sandra Ruiz, Lucía Zamora, Maria José Soler, Asunción Guillén, and Carmen María Vidal for their help in BALF samples collection and investigation support. This work was finacially supported by grant 20268/FPI/17 from Fundación Séneca assigned to Dra. Sonia Olmos, as well as by Project Number 6627/21IQA signed between FISABIO and Technical University of Cartagena, with financial help from Sociedad Valenciana de Neumología

Influence of wastewater treatment plants in microplastic discharges to surface water

Estudiar la abundancia de microplásticos y microfibras en las distintas etapas de funcionamiento de las depuradoras, identificando su naturaleza, composición y posibles efectos nocivos sobre las aguas receptoras.Escuela de Ingeniería de Caminos y MinasUniversidad Politécnica de Cartagen

Vídeo Egresados Graduación Caminos 2018

Vídeo en el que varios alumnos de la V Promoción de Máster en Ingeniería de Caminos, Canales y Puertos y VII Promoción del Grado en Ingeniería Civil relatan su paso por la UPCT y la importancia de ésta en su panorama laboral