Search Results (31)

Background/Objectives: Wastewater treatment plants (WWTPs) are recognized point sources of pharmaceutical residues and antimicrobial-resistant bacteria. This challenge is explicitly addressed in the 2024 recast of the Urban Wastewater Treatment Directive (UWWTD), which introduces risk-based obligations for micropollutant removal. Methods: Here, five antibiotics (azithromycin, clarithromycin, erythromycin, ciprofloxacin and sulfamethoxazole) were retrospectively (2017–2018) assessed in influent and effluent of four WWTPs and in their receiving waters (riverine and marine outfalls), including the Vistula Estuary. Measured incoming load (MIL) was compared with predicted incoming load (PIL), a cost-efficient proxy derived from outpatient consumption data. Results: The screening-level PIL–MIL consistency check showed closer agreement in catchments without major hospital inputs. In WWTPs, ciprofloxacin showed consistently high apparent aqueous-phase removal in both campaigns (>95%), sulfamethoxazole showed moderate removal (64–85%), while macrolides exhibited highly variable and sometimes apparent negative removal, yielding effluent concentrations up to 3989 ng L⁻¹ (azithromycin) and 2866 ng L⁻¹ (clarithromycin). Receiving waters generally contained < 10 ng L⁻¹ of the investigated antibiotics, but a low-dilution-capacity river showed a clear WWTP influence. Presumptive cefotaxime-resistant Escherichia coli, used as proxies for emerging ESBL/AmpC-associated resistance, reached ~5% and 20% of CFU downstream of WWTP discharges. Environmental (ERA) and AMR-related (AMR-RA) risk quotients (RQs) were mostly <0.1. However, RQs for azithromycin approached or exceeded unity in Gdańsk and Puck Bay. Coastal recipients are more vulnerable despite high dilution, since marine predicted no-effect concentrations (PNECs) for antimicrobials are lower than those for freshwater. Conclusions: The study supports the value of retrospective baseline data and site-specific screening frameworks for risk-based prioritization under the recast UWWTD. Full article

The vertical jacking method is a trenchless construction technique in which standpipes are jacked upward from a horizontal main pipeline through overlying soil, and it is widely applied in marine outfall projects. Taking a deep-sea tailwater outfall in Ningbo as the case study, this research develops a three-dimensional finite element model using ANSYS 2021 R1 based on actual geological and construction conditions. The settlement and stress responses of the horizontal main pipeline during jacking are analyzed and validated against field monitoring data. The numerical results agree well with the field measurements, with an average error of 7.29% for settlement and less than 9.83% for circumferential stress. The main pipeline exhibits a settlement pattern characterized by larger deformation in the middle and smaller at both ends, with a maximum value of 0.90 mm, decreasing with distance from the opening ring. Circumferential stress initially increases and then stabilizes, with maximum tensile and compressive stresses of 0.082 MPa and 0.056 MPa, respectively. Overall stress levels remain well below structural strength, indicating that structural damage is unlikely under the investigated conditions. These findings provide a case-based reference for structural design, construction control, and monitoring layout in marine outfall projects with similar geological and construction conditions. Full article

Monitoring marine outfalls is crucial for mitigating coastal pollution and protecting marine environments. Current methods rely mainly on manual inspection and satellite remote sensing interpretation, which are inefficient, inaccurate, and inadequate for large-scale real-time monitoring. Although UAV visible-light imagery has been introduced for marine outfall detection, challenges remain, including insufficient and diverse target features, small multi-scale target detection difficulties, and complex background interference. To address these limitations, this study systematically benchmarks mainstream object detection models (YOLOv8n, YOLOv9t, YOLOv10n, YOLOv11n, and RTDETR-light) on a dedicated multi-source remote sensing fusion dataset that we constructed for marine outfalls along Zhanjiang’s southern coast, incorporating NDWIs. Our comparative experiments evaluate the models’ effectiveness in this challenging scenario. Experimental results indicate that YOLOv8n is the most balanced model for marine outfall detection, achieving 84.1% precision, 68.6% recall, 77% mAP50, and an F1 score of 0.75. This benchmark provides empirical evidence and practical model selection criteria for intelligent marine outfall monitoring, thereby offering a reference framework for researchers and engineers in related fields. Full article

Environmental surveillance is important to monitor and mitigate antimicrobial resistance (AMR). In this context, sewage and its marine outfalls remain a hot spot for spreading AMR among pathogens. This study investigated the presence of drug-resistant Staphylococcus aureus in sewage effluent and marine sewage outfalls in Saudi Arabia. Water samples were collected from Jeddah’s southern and central marine outfalls and non-impacted sites. The isolates (n = 120) were identified through biochemical tests and MALDI-TOF. Resistance to antibiotics in the isolates was initially screened through phenotypic methods. Species-specific markers and antibiotic resistance genes (ARGs) were amplified through PCR. The presence of ARGs was also quantified in the isolates and in the environment through qPCR. The data indicated a higher prevalence of methicillin-resistant S. aureus (MRSA) in sewage effluent (63.3%) compared to marine water (50%). Sewage-borne MRSA exhibited higher resistance to various antibiotics. PCR detection confirmed the presence of mecA in MRSA isolates. Virulence genes encoding microbial surface components and recognizing adhesive matrix molecules (MSCRAMMs) were more prevalent in sewage isolates. Particularly, genes responsible for biofilm formation were more prevalent in the isolates from sewage samples. qPCR revealed a higher abundance of mecA, fnbB and bbp in sewage-derived isolates. Statistical analysis confirmed the strong influence of the sewage environment on the prevalence of drug-resistant isolates. Screening of environmental DNA further validated sewage as a reservoir of resistance and virulence determinants. These findings highlight the role of sewage outfalls in disseminating ARGs and virulent S. aureus strains, emphasizing the need to improve wastewater treatment and environmental surveillance strategies. Full article

Tidal dynamics substantially govern nearshore circulation patterns. The discharge of sewage at different tidal stages may have a significant impact on the dilution of pollutants. However, discussions on tidal phase sewage discharge strategy are still rare. This study focuses on the narrow tidal passage in the Ningbo-Zhoushan sea area, which receives a large amount of coastal wastewater, but the role of the unique hydrodynamic processes in the dilution of pollutants in this region remains unclear. By using a combination of on-site measurements and the FVCOM-dye simulation method, the scenario of high-concentration sewage retention in the tidal passage was demonstrated. The coastal residual circulation formed by strong tidal currents confined over 78% of the tracers within a 3 km range near the shore, and a subsurface dye accumulation zone emerged along the 25–50 m isobaths. Monsoon transitions regulated pollution plumes, inducing 5–8% seasonal variability in pollution footprints controlled by wind-tide-stratification interplay. The tidal phase discharge strategy was revealed to be highly effective in this study; both submerged discharge in deep-water zones and intermittent discharge strategies implemented in shallow-water zones significantly reduce the spatial coverage of high-concentration sewage plumes. Our findings highlight the importance of formulating discharge strategies based on tidal phases in typical narrow and deep tidal passages. Full article

This study investigates the implications of sewage contamination in the coastal and riverine environments of Hout Bay, Cape Town, South Africa. Chemical analyses were applied to quantify the presence of pollutants such as pharmaceutical and personal care products (PPCPs) in sentinel marine organisms such as mussels, as well as microbial indicators of faecal contamination in river water and seawater, for estimating the extent of impact zones in the coastal environment of Hout Bay. This research investigated the persistent pharmaceuticals found in marine outfall wastewater effluent samples in Hout Bay, examining whether these substances were also detectable in marine biota, specifically focusing on Mytilus galloprovincialis mussels. The findings reveal significant levels of sewage-related pollutants in the sampled environments, with concentrations ranging from 32.74 to 43.02 ng/g dry weight (dw) for acetaminophen, up to 384.96 ng/g for bezafibrate, and as high as 338.56 ng/g for triclosan. These results highlight persistent PPCP contamination in marine organisms, with increasing concentrations observed over time, suggesting a rise in population and pharmaceutical use. Additionally, microbial analysis revealed high levels of E. coli in the Hout Bay River, particularly near stormwater from the Imizamo Yethu settlement, with counts exceeding 8.3 million cfu/100 mL. These findings underscore the significant impact of untreated sewage on the environment. This study concludes that current sewage treatment is insufficient to mitigate pollution, urging the implementation of more effective wastewater management practices and long-term monitoring of pharmaceutical levels in marine biota to protect both the environment and public health. Full article

Land-based sources of marine outfalls are a major source of marine pollution. The monitoring of land-based sources of marine outfalls is an important means for marine environmental protection and governance. Traditional on-site manual monitoring methods are inefficient, expensive, and constrained by geographic conditions. Satellite remote sensing spectral analysis methods can only identify pollutant plumes and are affected by discharge timing and cloud/fog interference. Therefore, we propose a smart monitoring method for land-based sources of marine outfalls based on an improved YOLOv8 model, using unmanned aerial vehicles (UAVs). This method can accurately identify and classify marine outfalls, offering high practical application value. Inspired by the sparse sampling method in compressed sensing, we incorporated a multi-scale dilated attention mechanism into the model and integrated dynamic snake convolutions into the C2f module. This approach enhanced the model’s detection capability for occluded and complex-feature targets while constraining the increase in computational load. Additionally, we proposed a new loss calculation method by combining Inner-IoU (Intersection over Union) and MPDIoU (IoU with Minimum Points Distance), which further improved the model’s regression speed and its ability to predict multi-scale targets. The final experimental results show that the improved model achieved an mAP50 (mean Average Precision at 50) of 87.0%, representing a 3.4% increase from the original model, effectively enabling the smart monitoring of land-based marine discharge outlets. Full article

Stormwater management in coastal urban cities, where drainage networks are influenced by marine dynamics and specific soil and altimetry conditions, has specific challenges that need to be addressed to ensure adequate management in such areas, which are also heavily affected by floods. Their location downstream of drainage basins and the interaction of network outfalls with current and tidal variability increases the vulnerability of populations and should therefore be the target of specific studies. This article presents a literature review, where publications that focus on stormwater management in coastal urban areas were identified and analyzed. The main objective was to present the key issues related to drainage in coastal areas, the most relevant challenges, the solutions and strategies that reveal the greater potential for application and the challenges for modeling this type of case. It is intended to provide a grounded basis for new ways of optimizing stormwater drainage in coastal areas and promote a sustainable urban water cycle. This review reveals the necessity to implement a multidisciplinary approach to minimize three main issues: urban flooding, stormwater pollution and groundwater salinization, including the adaptation of existing infrastructures, complementing them with control solutions at source, correct urban planning and the involvement of populations. For an effective management of urban stormwater drainage in coastal areas, this approach must be carried out on a watershed scale, duly supported by reliable decision support tools and monitoring systems. Full article

Seagrass and seaweed meadows hold a very important role in coastal and marine ecosystems. However, anthropogenic impacts pose risks to these delicate habitats. This paper analyses the multitemporal impact of the construction of the largest industrial port in the Canary Islands, near the Special Area of Conservation Natura 2000, on Cymodocea nodosa seagrass meadows (sebadales) of the South of Tenerife, in the locality of Granadilla (Canary Islands, Spain). Very-high-resolution WorldView-2 multispectral satellite data were used for the analysis. Specifically, three images were selected before, during, and after the construction of the port (2011, 2014, and 2022, correspondingly). Initially, advanced pre-processing of the images was performed, and then seabed maps were obtained using the machine learning K-Nearest Neighbors (KNN) supervised classification model, discriminating 12 different bottom types in Case-2 complex waters. The maps achieved high-quality metrics with Precision values of 85%, 81%, and 80%, recall of 76%, 77%, and 77%, and F₁ scores of 80%, 79%, and 77% for 2011, 2014, and 2022, respectively. The results mainly show that the construction directly affected the seagrass and seaweed habitats. In particular, the impact of the port on the meadows of Cymodocea nodosa, Caulerpa prolifera, and maërl was assessed. The total maërl population was reduced by 1.9 km² throughout the study area. However, the Cymodocea nodosa population was maintained at the cost of colonizing maërl areas. Furthermore, the port sedimented a total of 0.98 km² of seabed, especially Cymodocea nodosa and maërl. In addition, it was observed that Caulerpa prolifera was established as a meadow at the entrance of the port, replacing part of the Cymodocea nodosa and maërl areas. As additional results, bathymetric maps were generated from satellite imagery with the Sigmoid model, and the presence of a submarine outfall was, as well, presented. Full article

Based on the study of the marine environmental capacity, a water quality model and a response field-based linear programming method are adopted here. Water quality control objectives are taken as the constraint conditions, according to the requirements of Jinpu Bay’s functional zoning. The pollutant response coefficient and water quality background value are combined with the values of the water concentration quality control points set in each functional area and the target value of the functional area wherein they are located. The maximum allowable emission intensity of inorganic nitrogen, phosphate and chemical oxygen demand (COD) can be calculated using the linear programming method of the maximum allowable emission of pollutants at estuaries or sewage outfall points on Jinpu Bay. The research results reveal the diffusion of marine pollutants and the marine environmental capacity of Jinpu Bay. Some rivers need to reduce the discharge intensity and some other outlets still have a certain residual capacity. Based on this, the environmental capacity of Jinpu Bay was evaluated, and a technical reference is provided for the economic development of the region and the formulation of pollutant emission control policies. Full article

Coastal municipalities and industries often discharge poorly treated wastewater into proximate marine and estuarine environments. The urban and/or effluent input can lead to eutrophication and lower water quality, as it holds high concentrations of nutrients and pollutants. One widely applied tool to increase effluent dispersion and direct it away from coastal areas, thus causing fewer impacts on human activities, is sea outfall. In Aveiro, Portugal, the São Jacinto sea outfall construction was completed in 1998; however, limited literature regarding the sea outfall’s monitoring using satellite data is available. The methodology in this study involved collecting four years’ worth (2016–2019) of satellite data to investigate visible traces of the interaction between the S. Jacinto sewage water mass and the Ria de Aveiro lagoon ecosystem using ocean color and spectral analysis, and producing new qualitative data regarding sea outfall plume dispersion monitoring through high-resolution Sentinel-2 imagery. The results showed a clear spectral signature of the sewage water mass, and a seasonal pattern was observed in which the plume was more evident in winter and autumn. Additionally, the coastal longshore current and the Aveiro lagoon’s runoff were able to restrict the marine outfall’s dispersion superficially. Ocean color data were revealed to be a factual and cost-effective tool to monitor the plume water. Finally, an exchange between the marine outfall water mass and Ria de Aveiro lagoon could happen in high tide under northern wind conditions. Therefore, it is important to monitor the water quality to ensure the coastal ecosystem’s good environmental state. Full article

The coupling of scientific evidence from sediment cores with historical information represents an effective way to reconstruct and quantify recent anthropogenic impacts in transitional and marine-coastal areas. These are both key points pertaining to studies that aim at establishing the responsibility for envi ronmental pollution. Good practices for the selection of sampling sites and specific survey techniques are fundamental to understand pollution histories and dynamics, together with reliable dating methods and analytical procedures. In addition, a certain degree of flexibility and willingness to explore different research pathways is necessary, particularly when unexpected questions arise from scientific data or from requests posed by authorities in charge of preliminary investigations or court debates. In this paper, two different study cases are reviewed, and the approaches developed to tackle with specific issues are presented. Its main purpose is both to explain study paths undertaken to answer challenging scientific-legal questions and to provide examples for developing countries that present similar risks of uncontrolled industrialization. Results were used in preliminary investigations or court debates for the attribution of responsibility for environmental pollution to past or present industrial managements. In addition, they were fundamental for other studies aiming at implementing models that simulate the fate and distribution of contaminants and human exposure. In the Augusta Harbor, an integrated approach merged archive information, bathymetry, and high-resolution seismic profiles with the results of an independent tracer (hexachlorobenzene, HCB). This approach helped attribute the presence of high surficial Hg concentrations to resuspension and redistribution of deep sediments caused by dredging and maritime traffic and not to active outfalls. In the Venice Lagoon, an extensive literature search supported analytical results for the correct identification of industrial processes responsible for the contamination by polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in the canals of the Porto Marghera Industrial Area. In addition, sedimentary profiles of PCDD/Fs in local salt marshes (“barene”) recorded well the events relative to the industrial development and management of the area reported by historical documents, confirming their potential for this kind of investigation. Full article

Marine pollution through anthropic outfalls like sewage pipes is a growing concern since point-source pollution can affect many organisms. Investigating pollutant concentrations in organisms usually requires sacrificing the organisms, but here we propose a new method to infer anthropic pollution in the intertidal by measuring colour levels in Palaemon elegans rockpool shrimp. We took pictures of live shrimp from pools near sewage pipes and control zones in three of the Canary Islands (Gran Canaria, Lanzarote and Tenerife), and measured their RGB (red, green and blue) abdominal colour composition. We then statistically compared colours from the control zone and sewage pipe and between islands. We found a clear differentiation in colour composition between the control zone and areas with a sewage pipe. Our results supported the hypothesis that pollution affects colouration in these invertebrates. We, therefore, suggest the use of darker colourations in P. elegans as a bioindicator of anthropic pollution, a first sign that should spur more in-depth studies in the affected area. This methodology is pollutant unspecific but non-extractive, so we propose its use as a citizen science tool to inform scientists and technicians of possible illegal and/or untreated wastewater that could affect intertidal biota. Full article

Coastal sediments in the proximity of wastewater and emergency outfalls are often sinks of pharmaceutical compounds and other organic and inorganic contaminants that are likely to affect the microbial community. The metabolites of these contaminants affect microbial diversity and their metabolic processes, resulting in undesirable effects on ecosystem functioning, thus necessitating the need to understand their composition and functions. In the present investigation, we studied the metagenomes of 12 coastal surface sediments through whole genome shot-gun sequencing. Taxonomic binning of the genes predicted about 86% as bacteria, 1% as archaea, >0.001% as viruses and Eukaryota, and 12% as other communities. The dominant bacterial, archaeal, and fungal genera were Woeseia, Nitrosopumilus, and Rhizophagus, respectively. The most prevalent viral families were Myoviridae and Siphoviridae, and the T4 virus was the most dominant bacteriophage. The unigenes further aligned to 26 clusters of orthologous genes (COGs) and five carbohydrate-active enzymes (CAZy) classes. Glycoside hydrolases (GH) and glycoside transferase (GT) were the highest-recorded CAzymes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) level 3 functions were subjugated by purine metabolism > ABC transporters > oxidative phosphorylation > two-component system > pyrimidine metabolism > pyruvate metabolism > quorum sensing > carbon fixation pathways > ribosomes > and glyoxalate and dicarboxylate metabolism. Sequences allying with plasmids, integrons, insertion sequences and antibiotic-resistance genes were also observed. Both the taxonomies and functional abundances exhibited variation in relative abundances, with limited spatial variability (ANOVA p > 0.05; ANOSIM-0.05, p > 0.05). This study underlines the dominant microbial communities and functional genes in the marine sediments of Kuwait as a baseline for future biomonitoring programs. Full article

The San Pedro del Pinatar I and II desalination plants in Spain were constructed near Posidonia oceanica meadows protected at the national and European level. The environmental impact statement for these plants stipulate that the brine discharge from the plant must not impact the meadows. To this end, a 4790 m submerged outfall was constructed to bypass the lower limit of the seagrass meadows, and a diffuser piece, along with an outfall pumping system, was installed at the end of the outfall. The objective of this paper is to evaluate the economic cost of the energy consumed for the brine discharge evacuation process necessary to comply with environmental requirements. The operating time and power consumption data were obtained from the plant’s monitoring system, while the energy cost was obtained from energy invoices. The computed results show that it is possible to minimize the environmental impacts of brine discharge on the marine environment of an SWRO plant with a low economic cost. The average energy consumption of the reject effluent pumping system ranged from 19.4 to 1239.3 thousand kWh per year, while the average annual energy cost was 49,329 €, which amounts to only 0.56% of the total energy cost for plant operation. The adoption of these measures provide a cost-effective means to meet environmental protection requirements and minimize the environmental impact associated with the discharged brine. As the demand for desalination operations increase, economically and scientifically viable technologies for mitigating environmental impacts are necessary for sustainability in this domain. Full article