The potential of microplastics as carriers of metals Godoy, V.; Blázquez, G.; Calero, M. ...
Environmental pollution (1987),
December 2019, 2019-Dec, 2019-12-00, 20191201, Volume:
255, Issue:
Pt 3
Journal Article
Peer reviewed
Microplastics can adsorb chemical pollutants such as metals or pharmaceuticals, and transferred them along the food chain. In this work, an investigation of the adsorption of Cd, Co, Cr, Cu, Ni, Pb ...and Zn by five different types of microplastics was performed in Milli-Q water and natural waters (seawater, urban wastewater and irrigation water) via a series of batch adsorption experiments. The effects of concentration of metals and physicochemical characteristics of polymers were particularly studied. Results revealed a significant adsorption of lead, chromium and zinc on microplastics, especially on polyethylene and polyvinyl chloride. In the case of polyethylene terephthalate, it showed little adsorption capacity. Specific surface, porosity and morphology are characteristics that affect the molecular interactions. The adsorption isotherms were better described by Langmuir model, which indicates that the main adsorption mechanism might be chemical adsorption. Finally, results obtained in natural waters indicated that dissolved organic matter may play a major role on metal adsorption on microplastics. Results showed an enhancement of metal adsorption in waters with high chemical and biological oxygen demands as urban wastewater and irrigation water.
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•PE, PP, PS and PVC showed fast adsorption to metals after 120 h of contact.•Sorption equilibrium fit better with Langmuir model than Freundlich model.•Cr and Pb were the metals adsorbed in most quantity in Milli-Q and natural waters.•Dissolved organic matter and pH influence the adsorption in natural waters.•Specific surface, porosity and morphology play important roles in the adsorption.
Main finding of the work: PE, PP, PS and PVC showed high potential as metal carriers. Combination of all properties of polymers influences the adsorption behavior. Higher adsorption was found in natural water with high organic matter content.
Plastic pollution in oceans is a global problem, with growing research efforts focusing on the threat of microplastics (<5 mm fractions). A source of microplastics pollution is derived from personal ...care products that contain polyethylene micro-spheres which are not captured by wastewater plants. In this work, ten personal care products (mainly scrubs) containing microplastics and marketed in Spain, were physico-chemically characterized. The obtained results proved that those microplastics had different particle size and are presented in high percentages in some cases, between 6 and 7% of the total product. Products with smaller particles usually showed higher concentrations than products with larger particles. Although all the microplastics were shown to be polyethylene, some impurities were observed that demonstrated the presence of silicates and oxides in the microplastics. Regards to morphology, the shape of the particles was irregular in general, although some completely spherical particles can be observed.
•More than 50% of scrubs marketed in Granada (Spain) contain microplastics.•Some personal care products contain up to 10% by weight of microplastics.•Microplastics were polyethylene with particle diameters between 8.7 and 2188 μm.•Between 123 and 3730 microplastics per gram were found in cosmetics products.•Chemical additives like silicon or aluminium oxides were present in the products.
The goal of this research was to develop new processes for the remediation of electroplating wastewater using olive stone as adsorbent material packed in fixed-bed columns. The study was performed ...with effluents containing chromium (VI), copper (II) and nickel (II) of an electroplating plant. First, we started our research from studying olive stone as an efficient biomaterial capable of removing chromium (VI) of both synthetic and real wastewater. The removal of chromium (VI) took place following two parallel mechanisms: the adsorption of chromium (VI) and the reduction of chromium (VI) to chromium (III) by contact with the biomass, appearing chromium (III) in the aqueous solution. Then, two fixed-bed columns were utilized for removal both chromium (VI) and chromium (III), in the first fixed-bed column, chromium (VI) was successfully removed and in the second column, the chromium (III). Finally, two types of adsorption experiments were selected for simultaneous adsorption of three metals: (1) with a first stage reduction of chromium and only one adsorption fixed-bed column; and (2) without the stage of reduction and two adsorption fixed-bed columns. The results showed that the second method was more suitable for the purposes of wastewater treatment. In the first column, chromium (VI) was completely removed. In the second column, the outlet concentration of heavy metals was 2.04, 1.48 and 0.93 mg/L for total chromium, copper (II), and nickel (II), respectively. This research provides a high efficient new alternative to clean industrial wastewater.
•Olive stone was studied as an efficient biomaterial capable of removing Cr (VI) of wastewater.•Reliable evidences about the removal mechanism of Cr (VI) by olive stone were presented.•A combined effect of sorption and reduction is involved in the Cr (VI) removal.•A new process for treatment of electroplating industry wastewater is proposed.
Fusaric acid (FA) is an important virulence factor produced by several
species. These fungi are responsible for wilt and rot diseases in a diverse range of crops. FA is toxic for animals, humans and ...soil-borne microorganisms. This mycotoxin reduces the survival and competition abilities of bacterial species able to antagonize
spp., due to its negative effects on viability and the production of antibiotics effective against these fungi. FA biodegradation is not a common characteristic among bacteria, and the determinants of FA catabolism have not been identified so far in any microorganism. In this study, we identified genes, enzymes, and metabolic pathways involved in the degradation of FA in the soil bacterium
T16. Our results provide insights into the catabolism of a pyridine-derivative involved in plant pathogenesis by a rhizosphere bacterium.
Camptothecins are broad-spectrum anticancer drugs that specifically target DNA topoisomerase I (Topo I). The formation of a cleavable drug–Topo I–DNA complex results in lethal double-strand DNA ...breakage and cell death. However, de novo or acquired clinical resistance to camptothecins is common. Studies of the camptothecin analog irinotecan suggest the following general mechanisms of resistance: (i) variable levels of the enzymes involved in the conversion of irinotecan; (ii) reduced cellular accumulation from active drug efflux; (iii) reduced levels of Topo I expression; (iv) alterations in the structure of Topo I from different mutations; (v) alterations in the cellular response to camptothecin–Topo I–DNA complex formation, which involves proteasome degradation of Topo I and/or enhanced DNA repair; and (vi) activation of the transcription factor nuclear factor kappa B by DNA damage and subsequent suppression of apoptosis. Multiple approaches using pharmacological and biological modulation to circumvent the above mechanisms of resistance have been incorporated into ongoing clinical trials and are expected to enhance the antitumor activity of irinotecan and reduce its systemic toxicity.
In the era of Industry 4.0 and 5.0, a transformative wave of softwarisation has surged. This shift towards software-centric frameworks has been a cornerstone and has highlighted the need to ...comprehend software applications. This research introduces a novel agent-based architecture designed to sense and predict software application metrics in industrial scenarios using AI techniques. It comprises interconnected agents that aim to enhance operational insights and decision-making processes. The forecaster component uses a random forest regressor to predict known and aggregated metrics. Further analysis demonstrates overall robust predictive capabilities. Visual representations and an error analysis underscore the forecasting accuracy and limitations. This work establishes a foundational understanding and predictive architecture for software behaviours, charting a course for future advancements in decision-making components within evolving industrial landscapes.
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•Fuel properties of the olive tree pruning were improved by torrefaction.•Changes in properties of solid are mainly sensitive to torrefaction temperature.•Higher heating value ...increased from 17.32MJ/kg to 20.50MJ/kg.•The hemicellulose is the component more affected during the torrefaction.•Effect of torrefaction on pyrolytic behavior of material was investigated.
In this work, the effect of experimental conditions of torrefaction on properties of olive tree pruning was investigated. This study has demonstrated that fuel properties of olive tree pruning were improved by torrefaction. For example, torrefaction at 300°C during 60min provided to raw biomass an increase on the ratio of fixed carbon to volatiles (from 0.23 to 0.39) and it improved its fuel quality. Elemental analysis revealed that the composition of olive tree pruning moved from lignocellulosic biomass to coal (for example, from O/C and H/C ratios of 1.02 and 0.17 for raw biomass to 0.90 and 0.15 for torrefied sample at 300°C during 10min). Also, as a result of torrefaction, a more homogeneous solid with higher heating value was obtained. However, bulk density of solid did not change significantly after torrefaction process. In addition, SEM analysis indicated that the olive tree pruning surface structure was broken and destroyed by torrefaction process. Also, the thermogravimetric analysis of native and torrefied samples in nitrogen atmosphere showed a strong degradation of hemicellulose and, also, in severe torrefaction conditions, a modification on the thermal stability of cellulose. Finally, an investigation on the pyrolysis kinetics of native and torrefied samples was presented. Lower energy activation values of main lignocellulosic pseudo-components were obtained for torrefied samples.
•PE and PS showed higher adsorption capacity for amoxicillin than PET, PP and PVC.•PET and PS showed higher adsorption capacity for phenol than PP and PVC.•Experimental data of sorption kinetics fit ...good to pseudo-second order model.•Sorption equilibrium fit better with Langmuir model than Freundlich model.•Desorption was more favourable at high temperature and pH around 6.
Microplastics have been converted a very important issue during current time. In addition, their capacity to adsorb other pollutants implies an additional problem. In this work, the potential of five types of microplastics derived from plastic waste, that include polyethylene, polyethylene terephthalate, polypropylene, polystyrene and polyvinyl chloride, to act as transporters of amoxicillin, atrazine, diuron, paracetamol, phenol and vancomycin was studied. Results suggested that microplastics, especially polyethylene, polyethylene terephthalate, polystyrene and polyvinyl chloride, revealed an essential protagonist as carriers of amoxicillin and phenol. The kinetic study showed that the sorption processes (from water to plastic) was slow and needs more than 28 days (amoxicillin) or about 21 days (phenol) to reach equilibrium. The modelling of equilibrium showed a better fit of the Langmuir model. The maximum Langmuir sorption capacities reached values between 4.03 and 8.80mg/g for amoxicillin and between 1.25 and 2.80mg/g for phenol. With respect to release tests, the liberation of the loaded pollutants was minor at the lower tested temperature (T =25°C) and lower tested pH (pH=2). Percentage of chemicals released increased between 1.3 and 7.9 times as the temperature increased until 40°C. Similarly, the results revealed that release was greatly pH dependent. In these experiments, a singular behaviour was observed for amoxicillin at 25°C, a combined effect of adsorption-release seems happen.
This research analyzes the potential use of the olive stone as a low-cost biosorbent for Cr (III) from aqueous solutions in a continuous system. First, experiments were carried out in fixed-bed ...column to test the influence of various parameters on breakthrough and saturation time. The breakthrough and saturation time increase with the decrease of the flow rate. The same effect is shown when the bed depth is increased. The olive stone sorption capacity,
q
e, increases as the inlet Cr (III) concentration increases until a value close to 0.800
mg/g is reached, then
q
e remains constant. Column data obtained at different conditions were described using the Adams–Bohart, Thomas, Yoon and Nelson, and Dose–Response models. The breakthrough curve prediction by the Adams–Bohart and Dose–Response models were found to be very satisfactory. In particular, the Adams–Bohart model can be used to represent the initial region of breakthrough curve, whereas the Dose–Response model is the one which best reproduces the whole curve for all the inlet Cr (III) concentrations used. Finally, a study of pH evolution was carried out. The pH increases at the beginning, subsequently decreasing as time passes until practically reaching the initial value.
In the era of Autonomous Networks (ANs), artificial intelligence (AI) plays a crucial role for their development in cellular networks, especially in 5G-and-beyond networks. The availability of ...high-quality networking datasets is one of the essential aspects for creating data-driven algorithms in network management and optimisation tasks. These datasets serve as the foundation for empowering AI algorithms to make informed decisions and optimise network resources efficiently. In this research work, we propose the IW-IB-5GNET networking dataset: an infrastructure-wide and intent-based dataset that is intended to be of use in research and development of network management and optimisation solutions in 5G-and-beyond networks. It is infrastructure wide due to the fact that the dataset includes information from all layers of the 5G network. It is also intent based as it is initiated based on predefined user intents. The proposed dataset has been generated in an emulated 5G network, with a wide deployment of network sensors for its creation. The IW-IB-5GNET dataset is promising to facilitate the development of autonomous and intelligent network management solutions that enhance network performance and optimisation.
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