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

Disinfection efficiency of secondary effluents with ultraviolet light in a Mediterranean area

This paper deals with the study of physicochemical and microbiological parameters affecting disinfection efficiency of secondary effluents in a municipal wastewater treatment plant, for irrigation purposes. There appears to be an important increase on turbidity values as chlorine values increases, due to the conversion of particulate organic carbon into dissolved organic carbon. The nitrification-denitrificacion processes appeared to be sensitive to changes in pH, with a minimum nitrate value in the wastewater when pH ranged between 7.01-8.00. With a similar behaviour, the phosphate removal was conditioned by pH, showing the highest efficiency in the same pH range. Both anions probed to be strongly correlated. Total coliforms were more UV light resistant than faecal coliforms, after an exposure of 10 min, corresponding to an UV dose of 73 mJ/cm2. The experimental results for both groups of microorganisms followed first order reaction kinetics, with a gradual flattening at higher UV doses. A total elimination of both indicators would be achieved with doses over 95 mJ/cm2. A previous step on the treated wastewater would improve its quality before the disinfection process

Microplastics in an urban wastewater treatment plant: The influence of physicochemical parameters and environmental factors

This paper presents the abundance, concentration and variability of microplastics (MP) in an urban wastewater treatment plant (WWTP), according to different water parameters and environmental factors, their possible sources and removal efficiency. A total of 352.6 L of wastewater from four stages of the treatment process were processed following a standardized extraction protocol by density separation, trinocular microscopic identification and polymeric analysis by Fourier transform infrared spectroscopy. MP comprised a 46.6% of total microlitter, with a statistically significant removal of 90.3% in the final effluent of the WWTP. Five different shapes were isolated; i.e. fragment, film, bead, fiber, and foam. The most prominent MP forms in the final effluent were fragments and fibers, with the most common size class being 400e600 mm. Seventeen different polymer families were identified, with low-density polyethylene being the most prevalent one (52.4%) in a film form (27.7%), mostly from agriculture greenhouses near the sewage plant and single plastic bags (it is noted that only a year ago consumers are charged for them in Spain). Influent wastewater with high concentrations of suspended solids proved to have a low MP burden with a larger MP size, possibly due to a hetero-aggregation with particulate matter. Agglomeration of polystyrene and polyethylene terephthalate with organic material is also suggested, both with surface energies higher than 25mNm 1 enough for a high biofouling rate. The sewage plant cushions sharp-point microplastic concentrations during the warm season, allowing a stable performance of the WWTP.This work was financed by Project 5245/18IQA (Cetenma and Hidrogea). Analyses carried out by S. Olmos were supported by a grant from Fundación Séneca (20268/FPI/17). Authors gratefully acknowledge the work and cooperation of personnel of the WWTP of Cartagena with wastewater samples collection

Characterization and removal efficiencies of microplastics discharged from sewage treatment plants in Southeast Spain

Microplastics (MPs) are ubiquitous pollutants that can effectively harm different ecosystems. The information on the relative contribution of wastewater treatment plants (WWTPs) to the surrounding environment is important, in order to understand ecological health risks and implement measures to reduce their presence. This focus article presents a quantitative assessment on the relative concentration and types of MPs delivered from four WWTPs located at the Southeast of Spain. Samples from WWTPs were collected throughout a four-year period, comprising more than 1,200 L of analyzed wastewater and 3,215 microparticles isolated. Density extraction with 1.08 g/mL NaCl salt solution was systematically used as the main separation method, in a simple and reliable manner, and repeat extraction cycles did not play any significant impact on the study outcomes. The four WWTPs had removal efficiencies between 64.3% and 89.2% after primary, secondary, and tertiary treatment phases, without diurnal or daily variations. Advanced treatment methods displayed a lower removal rate for fibers than for particulate MPs. The abundance of MPs was always higher and with a lower mean size in wastewater samples collected in Autumn than for the rest of seasons. MPs dumped from WWTPs in large quantities into the environment are meant to be regarded as an important point source for aquatic and terrestrial environments.This work was financed by Project 5245/18IQA (Cetenma and Hidrogea). Analyses carried out by S. Olmos were supported by a grant from Fundacion ´ S´eneca (20268/FPI/17). Authors gratefully acknowledge the work and cooperation of personnel of the WWTP of Cartagena with wastewater samples collection

Importancia de las plantas de tratamiento de aguas residuales (EDAR) como receptoras y fuente (efluentes tratados y fangos) de micropartículas plásticas

Es una evidencia y preocupación constatada la ubicua presencia de microplásticos (MP) en el medio ambiente y en el ciclo del agua, en particular en las aguas residuales. La presencia y existencia de MP, como nuevo contaminante emergente, se debe principalmente a actividades antropogénicas terrestres siendo las aguas residuales una de las vías de flujo hacia otros medios y en dónde las plantas de tratamiento de aguas residuales (EDAR) juegan un importante papel por su contribución. Los MP provienen tanto de fuentes primarias como secundarias, siempre con un tamaño entre 1 µm y 5 mm. Las EDAR son reconocidas tanto como receptoras (sumideros) como fuentes potenciales (efluentes tratados y fangos) de MPs, siendo el tratamiento de aguas residuales un paso crítico que debe ser considerado para una adecuada gestión del ciclo urbano del agua, especialmente en zonas áridas, donde se reutilizan las aguas tratadas y los fangos se destinan a uso agrícola. Aunque las EDAR no están expresamente diseñadas para eliminar MP, los actuales procesos de tratamiento parecen aportar altas eficiencias de eliminación (aunque variable, en general >90%), siendo las etapas de pretratamiento y primario donde se eliminan la mayoría de micropartículas entrantes; la comprensión de la eficiencia del tratamiento secundario mediante lodos activados convencionales y tecnologías de tratamiento avanzadas para eliminar micropartículas sigue siendo incompleta y requiere mayor comprensión. Entre otros estudios de los autores sobre MPs, éste muestra la importancia de lasetapas de tratamiento en su remoción, debido a la variedad de procesos de tratamiento que utilizan las diferentes EDAR. Para ello, se muestrearon cuatro depuradoras ubicadas en la Región de Murcia durante dos años. El proceso convencional de lodos activados (ASP) mostró las mejores eficiencias, con un 90.3% de las partículas de plástico, seguida de la tecnología MBR y filtración rápida de arena (RSF) como tratamiento terciario. Un proceso de doble tratamiento terciario, filtro de arena rápido seguido de desinfección ultravioleta, no mejoró la tasa de remoción. Las EDAR que utilizan solo tratamiento primario y secundario tuvieron una descarga promedio más alta de MP en el efluente final. La forma de MP más común en 4 EDAR fueron fibras, seguidas de películas, fragmentos y esferas. Los polímeros más comunes aislados fueron el polietileno de baja densidad, polipropileno, polietileno de alta densidad y acrilato, en clara coincidencia con la gran mayoría de plásticos producidos en el mundo. La extracción de microplásticos fue por densidad (NaCl 120 g/l) antes de filtración (0.45 µm); después de una selección inicial realizada con microscopio trinocular con cámara digital y registro de tamaño, forma y color para cada micropartícula en su dimensión más larga, se analizan grupos funcionales y composición molecular con espectroscopia infrarroja transformada Fourier (FITR). La importancia de su estudio, presencia, seguimiento, transporte y destino de los MP en aguas residuales es primordial para la puesta en marcha de acciones preventivas y correctivas por parte de toda la sociedad.Esta obra fue financiada por el Proyecto 5245/18IQA (Cetenma e Hidrogea). Los análisis realizados por S. Olmos fueron apoyados por una beca de la Fundación Séneca (20268/FPI/17). Los autores y Grupo de Trabajo de Microplásticos de la UPCT agradecen el trabajo y la colaboración de personal de las distintas EDAR objeto de estudio en la recogida de las muestras de fangos, a los técnicos del SAIT de la UPCT y de Cetenma en las determinaciones analíticas, así como a HIDROGEA, S.A. por el apoyo y colaboración al proyecto. El Instituto Nacional de Investigación del Ministerio de Ciencia, Educación y Universidades, reconoce e incluye en las Redes Temáticas de Investigación a la “Red Temática de Microplásticos y Nanoplásticos en el Medio Ambiente” (RED2018-102345-T), en la que se integra el Grupo de Trabajo de la UPCT, vinculado al desarrollo y ejecución del presente proyecto

Fuzzy topsis as a decision-support technique for the disinfection system selection in irrigation wastewater

The reuse of treated wastewater from wastewater treatment plants is an internationally-used practice with a large variety of applications, i.e. irrigation, urban and recreational uses, groundwater recharge, aquaculture, and industrial uses, among others. For all of these, the quality of the water should be taken into account. But it is also important to remark that the environmental and social impact derived from treated wastewater reuse is an intrinsically complex multidimensional process. Therefore, the final decision involves multiple criteria and multiple actors. On many occasions uncertain information is available on social and environmental factors so it is necessary to apply fuzzy tools to assess it. This work presents the use of multicriteria decision through the fuzzy TOPSIS method, applied to six different methodologies concerning the disinfection of treated wastewater prior to its reuse. For this purpose, a set of criteria and subcriteria through a series of pair-wise comparisons have been used with linguistic and non-linguistic information processed by the experts.This paper has been prepared under the projects, TIN2008 - 06872 - C04-04, which are financed by the DGICYT and Seneca 08824/PPC/08, funded by the Autonomous Community of Murcia, Spain

Toxicity assessment of chlorinated secondary effluents by the Vibrio fischeri bioluminescence assay

The objective of this manuscript was to assess the toxicity formation on biological treated wastewater from a municipal wastewater treatment plant, after a chlorination-dechlorination disinfection process. Water was monitored by means of physicochemical and ecotoxicological parameters, with the use of Vibrio fischeri bioassay. Since a dechlorination process removed residual chlorine, the positive correlation between toxicity values and chlorine concentrations suggested the formation of toxic disinfection by-products (DBPs). Statistically significant differences could be observed for toxicity values according to total carbon, total inorganic carbon, total nitrogen, chlorine, and pH. However, total organic carbon, chemical oxygen demand, electrical conductivity and turbidity had no statistical significance on toxicity formation. Three second-order polynomial equations were fitted between with total carbon and total nitrogen concentrations as independent variables, and EC50 as a dependent one

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)

Incidencia de la inclusión de los factores sociales y ambientales en la toma de decisión mediante métodos multicriterio

Technical and economic factors have to date been the principal points to take into account in decision making in engineering projects. It has become increasingly patent that social and environmental criteria need to be tackled within these problems. Thus we can see how the social acceptance regarding a company policy or the environmental benefits of one or other production alternative, are factors that have an increasingly greater weight in these decisions. It is for that reason that we present the case of the election of a disinfection system for treated waste water for agricultural use. In this case, water quality, costs, social and environmental criteria have been considered. We have been able to observe, by means of a sensitivity analysis, how the final decision changes depending on the weight given to these factors. For each of the experts consulted the inclusion of these factors leads to certain alternatives being prioritized over others, a situation which did not occur when only quality and cost factors were considered

Evaluation of physichochemical parameters influencing bulking episodes in a municipal wastewater treatment plant

A study of physicochemical parameters in a municipal wastewater treatment plant was undertaken to consider the presence of bulking phenomena by means of statistical and logistic regression analyses. There appears to be an important effect on activated sludge settleability that can be related to the temperature of wastewater. Besides, there were significant differences between the percentage of nitrogen removal from the secondary treatment with the season. The SVI increased with conductivity, meanwhile BOD5 removal decreased with this parameter. The development of logistic regression models identified two statistically significant variables that appeared to be important to the contribution of a higher SVI: season and pH