En este manual se detalla el protocolo de muestreo de microplásticos en agua superficial que utiliza el IEO-Vigo en las campañas de ESMARES6-C8. | Peer reviewed

En este manual se detalla el protocolo de muestreo de microplásticos en agua superficial que utiliza el IEO-Vigo en las campañas de ESMARES6-C8.

River sediments have the capability to accumulate and absorb traces of anthropic environmental degradation. In this work, we investigated the effects of urban land use on the composition of physical sediment. For this purpose, sediment profiles were collected in the wet and dry seasons and in locations with mixed land-use. For the sediment analysis, particle size separation, organic matter degradation, visual analysis of the thickest fraction using a magnifying glass and stereomicroscope analysis of the particle size material corresponding to the sands were performed. It was observed that the sedimentation of synthetic materials and plastics (fragments and fibres) were the most frequently found materials. More intense urban occupation areas and with less riparian vegetation suffer more from this degradation than rural areas or areas with preserved riparian vegetation. The dam in the basin accumulates more materials (macro and microplastics) and has the role of containing and preventing these residues from being transported downstream. The importance of investing in environmental management measures is emphasized, and based on the sampled sites assessed, the restoration of riparian vegetation, greater inspection of inadequate waste disposal and public cleaning actions are suggested, including actions in the Tibiriçá dam.

El río Frío se ha visto afectado por la contaminación con bolsas plásticas provenientes de la actividad bananera en el municipio, las cuales terminan en el cuerpo de agua por acción del viento, donde se fragmentan debido a factores ambientales que causan su degradación, generando microplásticos. Entender cómo sucede este proceso es esencial para la toma de decisiones, por lo que esta investigación tiene como objetivo evaluar química y físicamente el proceso de degradación del polietileno bajo condiciones de calidad del agua de la cuenca baja del río Frío. Para esto, se identificaron los factores ambientales más influyentes sobre la degradación del PEBD en el río, donde los principales fueron la exposición a radiación UV, la temperatura y calidad del agua en términos de nitratos, pH y fosfatos. Luego, se simularon las condiciones naturales del río mediante un montaje experimental y se analizaron los cambios morfológicos y las variaciones de masa de tres fragmentos de plástico durante 28 días a 10ºC, 25ºC y 40ºC, para un total de 72 fragmentos analizados. Con esta información, se estableció la cinética de degradación del PEBD, obteniendo las constantes de velocidad (k) y las energías de activación (Ea), así como la Ley de velocidad para cada caso. Lo anterior se correlacionó con los factores ambientales antes mencionados y se encontró que la radiación UV fue lo que más influyó sobre la constante de velocidad de la reacción, seguido del aumento de la temperatura y la calidad del agua. Esta información servirá como punto de partida para la construcción de un modelo matemático de la degradación del PEBD en condiciones naturales, facilitando la toma de decisiones acerca de la contaminación de microplásticos en el río Frío, para tomar acción desde la ingeniería ambiental con el uso de estrategias que permitan reducir esta contaminación. | Ingeniero Ambiental | Pregrado | The Frío river has been affected by plastic bags coming from banana industry, which reaches the environment by wind-driven transport and subsequently are fragmented by the effects of environmental factors that cause its degradation, generating microplastics. It is essential to understand how this process works in order to make decisions about it, consequently the main purpose of this research is to evaluate chemically and physically how is the degradation process of LDPE at the river, under water quality conditions of the lower basin of Frío river. To achieve this, the most important environmental factors were identified as UV exposure, water temperature and water quality in terms of nitrates, pH and phosphates. Then, natural river conditions were simulated with an experimental set-up and morphology changes in the material were analyzed along with mass changes of the plastic fragments for 28 days at 10ºC, 25ºC and 40ºC, for a total of 72 fragments analyzed. From this information, it was possible to determine the degradation kinetics of LDPE, obtaining the reaction rate coefficients (k) and the activation energies (Ea), as well as the rate law. Previous results were correlated with the environmental factors mentioned and it was found that UV exposure was the factor that influenced the most on the reaction rate coefficient, followed by the increase on temperature and water quality. This information will also serve as a starting point for the construction of a mathematic model of LDPE degradation under natural conditions, facilitating decision making with regard to the microplastics contamination at Frío river, in order to take action from environmental engineering by using strategies that will allow to reduce this contamination.

En la actualidad, una de las grandes amenazas que se presenta en la vida marina es la contaminación por plásticos provenientes en mayor parte por fuentes terrestres, llegando a niveles alarmantes, como lo mencionan las Naciones Unidas en el ODS 14: por cada kilómetro cuadrado de océano hay un promedio de 13.000 trozos de desechos plásticos, que cuando se degradan generan los denominados “microplásticos”. De igual forma, el uso masivo de desechos plásticos y la baja degradación de estos residuos ha conducido a que no solo se afecte a los ecosistemas, sino también a que se presenten problemas de contaminación persistentes en los cuerpos de agua. En Colombia existen muchos afluentes hídricos que han sido contaminados por el mal uso de deshechos plásticos arrojados a sus aguas, una de las fuentes hídricas con mayor presencia de contaminación es el rio Magdalena, específicamente la cuenca media ubicada en el Municipio de Honda, por las diversas actividades socioeconómicas que se llevan a cabo a lo largo de este sistema hídrico. Por lo anterior, la presente investigación presenta como objetivo: Evaluar in vitro e in silico la actividad enzimática del hongo Pleurotus ostreatus sobre microplásticos de polietileno de baja densidad presente en una muestra de agua de la cuenca media del rio Magdalena a escala de laboratorio. El desarrollo del proyecto se ejecutó en dos fases; la primera fase es el desarrollo in vitro, en esta se evaluó la capacidad de crecimiento del hongo Pleurotus ostreatus sobre los microplásticos sometido a diferentes inductores, la interacción entre estos, un análisis fisicoquímico de las muestras obtenidas de la cuenca, la determinación de la presencia de microplásticos en la cuenca y la adhesión del microplásticos con el Pleurotus ostreatus a través de un análisis de microscopia de barrido. La segunda fase es el desarrollo in silico, la cual determino las interacciones moleculares entre las enzimas del Pleurotus ostreatus involucradas en el mecanismo de degradación del polietileno de baja densidad a través de modelamiento y dinámica molecular. | Bioingeniero | Pregrado | Currently, one of the greatest threats to marine life is plastic pollution, mostly from land-based sources, reaching alarming levels, as mentioned by the United Nations in SDG 14: for every square kilometre of ocean there is an average of 13,000 pieces of plastic waste, which, when degraded, generate the so-called "microplastics". Similarly, the massive use of plastic waste and the low degradation of this waste has led not only to ecosystems being affected, but also to persistent pollution problems in water bodies. In Colombia there are many tributaries that have been polluted by the misuse of plastic waste thrown into their waters, one of the water sources with the greatest presence of contamination is the Magdalena River, specifically the middle basin located in the municipality of Honda, due to the various socio-economic activities that are carried out in the area. The objective of this research is to evaluate in vitro and in silico the enzymatic activity of the fungus Pleurotus ostreatus on microplastics of low density polyethylene present in a sample of water from the middle basin of the Magdalena River on a laboratory scale. The development of the project was carried out in two phases; the first phase is the in vitro development, in which the growth capacity of the fungus Pleurotus ostreatus on the microplastics was evaluated under different inducers, the interaction between these, a physicochemical analysis of the samples obtained from the basin, the determination of the presence of microplastics in the basin and the adhesion of the microplastics with the Pleurotus ostreatus through a scanning microscopy analysis. The second phase is the in silico development, which determined the molecular interactions between Pleurotus ostreatus enzymes involved in the degradation mechanism of low density polyethylene through modelling and molecular dynamics.

The processes of microplastic fiber pollution in groundwater are unknown. The recent research on this contaminant threat is generally focused on surface waters (mainly oceans and rivers), while aquifer contamination is only marginally mentioned as an issue needing further investigation. Synthetic microfibers can be introduced into soils in different ways (e.g. wastewater treatment plants or greywater discharge, septic tank outflows, direct injection of contaminated water in cases of managed aquifer recharge, losing streams, etc.), and can thus reach aquifer systems due to leaching or infiltration in soil pores. Microfibers can then adsorb persistent bioaccumulative and toxic chemicals, which include persistent organic pollutants and metals, and become a carrier of harmful substances in the aquifer system, hence contributing to the overall contamination in both urban and rural areas. For this reason, it is of paramount importance, not only to assess the occurrence and fate of microplastic fibers in groundwater, but also to study the role of microplastics as carriers of contaminants within the aquifer and to advance standardization and organization of monitoring campaigns. Only by addressing these key challenges can hydrogeologists contribute to the state of the art on microplastic pollution and ensure that groundwater is not neglected in the environmental assessments tackling this contaminant of emerging concern.