Abstract The Tara Microplastics mission was conducted for 7 months to investigate plastic pollution along nine major rivers in Europe—Thames, Elbe, Rhine, Seine, Loire, Garonne, Ebro, Rhone, and Tiber. An extensive suite of sampling protocols was applied at four to five sites on each river along a salinity gradient from the sea and the outer estuary to downstream and upstream of the first heavily populated city. Biophysicochemical parameters including salinity, temperature, irradiance, particulate matter, large and small microplastics (MPs) concentration and composition, prokaryote and microeukaryote richness, and diversity on MPs and in the surrounding waters were routinely measured onboard the French research vessel Tara or from a semi-rigid boat in shallow waters. In addition, macroplastic and microplastic concentrations and composition were determined on river banks and beaches. Finally, cages containing either pristine pieces of plastics in the form of films or granules, and others containing mussels were immersed at each sampling site, 1 month prior to sampling in order to study the metabolic activity of the plastisphere by meta-OMICS and to run toxicity tests and pollutants analyses. Here, we fully described the holistic set of protocols designed for the Mission Tara Microplastics and promoted standard procedures to achieve its ambitious goals: (1) compare traits of plastic pollution among European rivers, (2) provide a baseline of the state of plastic pollution in the Anthropocene, (3) predict their evolution in the frame of the current European initiatives, (4) shed light on the toxicological effects of plastic on aquatic life, (5) model the transport of microplastics from land towards the sea, and (6) investigate the potential impact of pathogen or invasive species rafting on drifting plastics from the land to the sea through riverine systems.

Microplastics provide a persistent substrate that can facilitate microbial transport across ecosystems. Since most marine plastic debris originates from land and reaches the ocean through rivers, the potential dispersal of freshwater bacteria into the sea represents a significant concern. To address this question, we explored the plastisphere on microplastic debris (MPs) and on pristine microplastics (pMPs) as well as the bacteria living in surrounding waters, along the river-sea continuum in nine major European rivers sampled during the 7 months of the Tara Microplastics mission. In both marine and riverine waters, we found a clear niche partitioning among MPs and pMPs plastispheres when compared to the bacteria living in the surrounding waters. Across this large dataset, we found that bacterial community structure varied along the river salinity gradient, with plastisphere communities exhibiting almost complete segregation between freshwater and marine ecosystems. We also described for the first time a virulent human pathogenic bacterium (Shewanella putrefaciens), capable of infecting human intestinal epithelial cells, detected exclusively on MPs in riverine environments. Our findings indicate that salinity is the main driver of plastisphere communities along the river-to-sea continuum, helping to mitigate the risk of pathogens transfer between freshwater and marine systems.

Mangrove ecosystems are known to play a key role in the global carbon cycle, due to their productivity and their ability for carbon sequestration both in the biomass and in the soil. In the latter, various geochemical processes lead to the production of dissolved organic matter (DOM) that can be exported through tidal pumping and then constitute an important source of organic carbon for adjacent ecosystems. DOM characteristics, and their variabilities, within mangrove soils depend on several factors, including the mangrove species, yet these variations and their origin still need to be precisely constrained. This study examined DOM sources in soils of a carbonate atoll mangrove (Ouvéa, New Caledonia), focusing on two tree species, Rhizophora apiculata and Bruguiera gymnorhiza, at different growth stages. We analysed porewater properties and DOM optical characteristics through spectroscopic and EEM-PARAFAC methods. Our results indicate distinct TOC and DOC concentrations across species, with mature B. gymnorhiza soils showing the highest TOC content (~ 30%) but the lowest DOC content (32 mg L−1). These differences seem not to be directly related to site physicochemical conditions (redox, pH, salinity) but may rather reflect differences in DOM sources and production, notably due to different symbiotic relationships with mycorrhizal fungi, which influence microbial activity and organic matter diagenesis. DOM absorbance patterns also varied significantly between species: Beneath R. apiculata, DOM had higher protein-like and fulvic-like fluorescence, indicating fresher organic matter, while beneath B. gymnorhiza, especially in mature stands, DOM was more humified, suggesting older OM because of a possible long-term accumulation due to the basin-like morphology of this site.

Noble metal decorated metal oxide composites have proved to have Surface plasmon resonance (SPR) as a notable approach for efficient light absorption. Herein present work, a new sonochemical method is proposed for in-situ synthesis of noble metal-based CeO2 composites for the sonophotocatalytic degradation of commercial Acephate solution. Pristine CeO2 and Ag@CeO2 with different Ag contents viz. 4, 6 and 8 wt. % were successfully synthesized by a facile in-situ sonochemical approach. The as-synthesized CeO2 and Ag@CeO2 nanocomposites were characterized by various physicochemical characterization techniques, including XRD, FTIR, UV-Vis spectroscopy, BET, and FESEM-EDS. Further, these CeO2 and Ag@CeO2 nanocomposites were employed for photocatalytic, sonocatalytic, and sonophotocatalytic degradation of commercial Acephate solution. Experimental results revealed that the photocatalytic and sonocatalytic processes follow a pseudo-first-order model, whereas the sonophotocatalytic process had a more substantial rate constant compared to the photocatalytic and sonocatalytic one. Further, the kinetics of the study were examined by the Langmuir-Hinshelwood model. Overall, the sonophotocatalytic degradation involving as-synthesized Ag@CeO2 with 6 wt. % Ag content has shown to be the most effective method for the effective degradation of a commercial acephate solution.

Recently, Extended Producer Responsibility (EPR) schemes have been considered as potential policies for solid waste management and many countries have applied them. Researchers, authorities, and producers need a comprehensive and up-to-date understanding of EPR. Therefore, this literature review aims to review the current research status of EPR implementation on packaging, to highlight actual experiences conducting EPR, and to find research gaps. Results indicate that during the last 5 years, there has been an increase in the amount of research on EPR in packaging and that packaging waste recycling under this scheme is the most considered activity. Additionally, the primary metrics used to assess the efficacy of EPRs are recycling and reducing packaging waste. According to the lessons learned, applying EPR to packaging should take stakeholder engagement, policy design, transparency, and incentive strategy into account. Additionally, knowing the economic effectiveness problems small- and medium-sized packaging companies face, the effectiveness of EPR methods on various materials and geographical areas, and the efficacy of monitoring methods are the main areas that need to be researched.

A major global concern is the widespread environmental destruction caused by hydrocarbons, especially from the dumping of spent engine oil. Hydrocarbons are a major source of pollution in the environment and have an impact on agriculture, aquatic life, and soil fertility. The necessity of resolving this issue is highlighted by the detrimental impact on soil biocenosis and the potential conversion of soils into technogenic deserts. Due to high costs and polluting byproducts, the conventional approach of treating contaminated soil, sediment, and water is unsustainable. However, bioremediation, which makes use of biological agents like fungi and bacteria, appears to be a more practical and affordable solution. Microbial biosurfactants present a possible solution for environmental restoration due to their less harmful nature compared to chemical surfactants. This review highlights the green and sustainable nature of microbial biosurfactants while examining their advancements, biotechnological potentials, and future possibilities for bioremediation. The review also looks at the genetic basis and economic viability of biosurfactants for bioremediation applications. Furthermore, the review emphasizes the need for more studies in overcoming the challenges of large-scale application of biological surfactants for bioremediation of pollution and environmental restoration. As partners in nature, these bacteria aid in the breakdown of hydrocarbons, highlighting the need for industry and the environment to coexist sustainably. As biosurfactants are less harmful to the environment than chemical surfactants, they are more in line with the global trend toward sustainable methods and the use of natural processes for ecological restoration.

Improper disposal of landfill leachate, a highly polluted wastewater, can harm living beings and the ecosystem. Of all the treatment technologies available, electrochemical techniques have the most advantages in terms of ease of use, affordability, and the ability to degrade various contaminants found in landfill leachate effectively. Though there are a sufficient number of research articles regarding the electrochemical treatment of leachate, it has many research gaps, such as a study on the mechanism of radicle generation, pollutant degradation, study on different electrodes with various pollutants concentrations, application of green catalysts, byproduct formation assessment, energy recovery, etc. This review article explores the applications of electrooxidation techniques for the treatment of landfill leachate. Key aspects discussed include the (i) fundamental concepts in electrochemical treatment and its mechanism, (ii) factors affecting the electrochemical treatment efficiency, (iii) the applicability of leachate treatment with different electrochemical methods, (iv) recent advances, (v) merits, and demerits and (vi) proposal of future scope and the studies needed. The integration of electrooxidation with other treatment processes and the challenges hindering widespread adoption are also addressed. Overall, electrooxidation demonstrates promise as an effective and sustainable method for managing landfill leachate. Consequently, this article directs chacurrent and future research efforts toward optimizing the leachate treatment through electrooxidation techniques.

Heavy metal (HM) pollution has been a significant issue for the environment and public health. Unmonitored industrial effluents are a major source of HM pollution. However, metallotolerant bacteria thriving in such environments could be potentially useful for bioremediation purposes. In this study, Bacillus cereus IEI-01 was isolated from water samples of Badshahpur Lake, Gurugram, showcasing resilience to HM exposure and thriving under optimal conditions at 37°C and pH 7.0. Morphological and biochemical characterization showed its Gram-positive rod shape and metabolic versatility, including glucose fermentation and nitrate reduction capabilities. Molecular analysis further affirmed its close relation to the Bacillus cereus strain. Dynamic bacterial growth patterns were observed, with typical sigmoidal curves indicating significant growth over 72 h. When exposed to various HMs, the strain IEI-01 exhibited differential tolerance and promoting patterns, with cadmium (Cd) and lead (Pb) compared to other metals. Over 72 h, the strain exhibited substantial removal rates ranging from 60.64% to 87.43% for Cd and 41.87% to 52.62% for Pb. The concentration-dependent bio-removal efficiency of IEI-01 in Cd-spiked cultures displayed a declining trend with increasing concentrations, with removal rates ranging from 80.23% to 60.72% over the same period. These findings highlight the potential of Bacillus cereus IEI-01 for HM bioremediation, particularly at lower concentrations. Its efficacy in removing Cd and Pb from contaminated environments suggests promising applications in environmental cleanup efforts.

Microplastic pollution has become a global concern with potentially severe environmental and health implications. This research explores the level of knowledge and awareness about microplastics among the urban population of Pune, a busy city in India. A mixed-methods approach was employed using a sequential explanatory design. In the first phase, qualitative data were gathered through semi-structured interviews with 18 participants selected via purposive sampling. In the second phase, quantitative data were collected from 100 participants using a survey and convenience sampling. By combining insights from surveys, interviews, and existing literature, the study analyzed the extent to which residents of Pune are informed about microplastic pollution and their willingness to take action. The findings highlight the need for increased awareness campaigns and educational initiatives to address the growing microplastic problem in urban areas. The study concludes that plastics have become an integral part of our lives, necessitating robust mechanisms to eliminate them from daily use.

The objective of the current research is to measure the specific activity of 40K and heavy metals in the water samples collected from the Al-Diwaniyah River in Al-Qadisiyah Governorate, Iraq. The activity of 40K in water samples was ascertained using High Purity Germanium Spectrometer (HPGe) detector technology, which is based on a high-resolution gamma spectrometry system, and by using an atomic absorption spectrometer (A.A.S.) to determine the heavy metals of Ni, Cd and Pb, as well as measure some of the physical properties of water samples. The results indicated the concentration of 40K in the water was presented in different concentrations. The lowest value was 2.6±0.5 Bq/L Al-Muhanawiyah, while the highest value was in Al-Diwaniyah center 24.6± 4.0Bq/L. On the other hand, the highest results of Pb, Cd and Ni have been 0.1247, 0.0652 and 0.157 ppm, respectively. While, the results of physics properties were from 7.05 to 8.3 for total dissolved solids (T.D.S.) values were from 2100 to 756.6 mg/L, electrical conductivity values were between 1140 and 3500 μs/cm, and turbidity values were between 7.0 and 54.5. Based on the results, the concentrations of the 40K and heavy metals indicated that the results are almost slight compared to internationally accepted values.