Pollutant Discharge Research Articles

COAGULATION AND FLOCCULATION PROCESSES IN WATER TREATMENT: CHOOSING THE CATALYST WITH THE BEST COST-BENEFIT RATIO

One of the current problems in water bodies is the loss of transparency and water quality, which, in general, is caused by anthropogenic actions such as agriculture and industries, when there is a release of pollutants generated by them, resulting in the loss of its quality. The gap that determined this research was the low number of studies to disseminate chemical tests and methods that contribute to the mitigation of costs and increase the effectiveness of WTPs. For this reason, this study aims to identify a catalyst with the best cost-benefit ratio in the removal of particles that promote water turbidity and, in this way, obtain a higher transparency index, which increases the photosynthetic rate and the physiology of this natural resource. The research methodology applied was observational, systematic, direct, experimental, associated with a survey of secondary data with a period in the period from 2007 to 2024. Statistical analysis of the data occurred with the application of descriptive statistics (maximum, minimum, median, mean, and standard deviation) and Principal Component Analysis (PCA). The coagulant used in this research was Polychloride for the measurement, Hydrated Lime Ca(OH)2 [14%] and Sodium Hydroxide (NaOH) [10%] were applied. The data obtained and analyzed indicated that NaOH [14%] presented a higher performance in terms of coagulation reaction speed (one minute), while Ca(OH)2 [14%] proved to be more efficient in terms of flake morphology (note 3) and decantation speed (nine minutes).

Environmental technology’s diminishing marginal returns: a study of green patents and emission reductions in China

IntroductionDo environmental technologies always yield desirable returns? This study addresses this question through the lens of command-and-control environmental regulation. It explores the theoretical and empirical mechanisms influencing the efficacy of technology in reducing emissions, focusing on the non-linear characteristics of technological returns under equilibrium conditions.MethodsA socio-economic model integrating pollution discharge issues was developed to examine the marginal effects of emission reduction technology. Empirical validation was conducted using green patent data from Chinese listed companies (2005–2020) and pollution emissions data from various cities. Fixed effects models and generalized random forest models were employed to analyze the relationships.ResultsThe analysis revealed that technological innovation exhibits diminishing marginal returns in reducing emissions due to existing technological constraints. The results were further dissected by categorizing patents and city characteristics, shedding light on the factors influencing emission reduction effectiveness.DiscussionThe findings emphasize the importance of addressing the non-linear nature of technological innovation in environmental regulation. Policy recommendations include fostering tailored innovation strategies and supporting cities with unique characteristics to maximize technological impact on emission reduction.

Dataset of microscale atmospheric flow and pollutant concentration large-eddy simulations for varying mesoscale meteorological forcing in an idealized urban environment.

By 2050, two-thirds of the world's population will live in urban areas under climate change, exacerbating the environmental and public health risks associated with poor air quality and urban heat island effects. Assessing these risks requires the development of microscale meteorological models that quickly and accurately predict wind velocity and pollutant concentration with high resolution, as the heterogeneity of urban environments leads to complex wind patterns and strong pollutant concentration gradients. Computational Fluid Dynamics (CFD) has emerged as a powerful tool to address this challenge by providing obstacle-resolved flow and dispersion predictions. However, CFD models are very expensive and require intensive computing resources, which can hinder their systematic use in practical engineering applications. They are also subject to significant uncertainties, particularly those arising from the mesoscale meteorological forcing and the internal variability of the atmospheric boundary layer, some of which are aleatory and thereby irreducible. Given these issues, the construction of CFD datasets that account for uncertainty would be an interesting avenue of research for microscale atmospheric science. In this context, we present the PPMLES (Perturbed-Parameter ensemble of MUST Large-Eddy Simulations) dataset, which consists of 200 large-eddy simulations (LES) characterizing the complex interactions between the turbulent airflow, the tracer dispersion, and an idealized urban environment. These simulations reproduce the canonical MUST dispersion field campaign while perturbing the model's mesoscale meteorological forcing parameters. PPMLES includes time series at human height within the built environment to track wind velocity and pollutant release and dispersion over time. PPMLES also includes complete 3-D fields of first- and second-order temporal statistics of the wind velocity and pollutant concentration, with a sub-metric resolution. The uncertainty of the fields induced by the internal variability of the atmospheric boundary layer is also provided. The computation of PPMLES required significant resources, consuming 6 million CPU core hours, equivalent to the emission of approximately 10 tCO2eq of greenhouse gases. This significant computational effort and associated carbon footprint motivates the sharing of the data generated. The added value of the PPMLES dataset is twofold. First, the perturbed-parameter ensemble of LES enables to quantify and understand the effects of the mesoscale meteorological forcing and the internal variability of the atmospheric boundary layer, which has been identified as a major challenge in predicting atmospheric flow and pollutant dispersion in urban environments. Secondly, PPMLES reference data can be used to benchmark models of different levels of complexity, and to extract key information about the physical processes involved to inform more operational modeling approaches, for example through learning surrogate models.

Disinfection inducing release of contaminants from baby play mats: Microplastics and volatile organic compounds.

Baby play mats serve as essential protective equipment widely utilized in residences, daycares, and kindergartens. Given their direct contact with infants and young children, the pollutants released from play mats may pose potential health risks. This study investigated the impact of disinfection on the release of microplastics (MPs) from play mats and offers an in-depth analysis of the derived volatile organic compounds (VOCs) release. The results revealed that various disinfection treatments promoted the release of MPs from play mats. Among them, chlorination bleaching induced play mats to produce 2-3 times less MPs than ultraviolet sterilization (UVS) and UV-bleaching disinfection. The generation potential of MPs derived from play mats of different materials was ranked as polyethylene terephthalate (PET)>polypropylene (PP)≈polyethylene (PE)>polyvinyl chloride (PVC). Furthermore, PE play mat released highest concentration of total VOC after disinfection, increasing from 1.82mg/m2 (control) to 15.82mg/m2 (UV-bleaching). However, PVC released the most species of VOCs, with 76 species identified through non-target screening, such as several alkanes, alkenes, alcohols, ketones, etc. Through toxicological prediction, VOCs with high toxic potential were identified. Individual VOCs from PP, such as Pentadecane (CAS: 629-62-9), exhibited high yields at 3.16ng/g after UV-bleaching treatment. In conclusion, chlorination bleaching is safer than UVS and UV-bleaching disinfection in mitigating the release of pollutants from play mats.

Occurrence of priority and emerging organic contaminants in cold-water corals and their habitat: a case study in La Herradura Bay (Spain).

Coastal ecosystems are heavily anthropized areas impacted by discharge of chemical pollutants. We present for the first time the occurrence of a wide number of such chemicals in surface water, sediment, suspended particulate matter, and corals from a protected Mediterranean setting, La Herradura Bay (Spain). A seasonal monitoring sampling campaign was conducted in 2021 (winter and summer). This bay is a marine biodiversity hot spot and home for endangered cold-water corals species (Astroides calycularis and Dendrophyllia ramea). Up to 94 target analytes were present in marine samples, with pharmaceuticals being the predominant compound class (up to 37 ng L-1 in seawater and 775 ng g-1 in sediments), especially during the winter season. Uncontrolled untreated wastewater discharges in combination with hydrodynamics dominating in the area seemed to be the major source of contaminants towards the coral colonies inhabiting the bay, which accumulate pharmaceuticals (up to 154 ng g-1), personal care products (UV filters and synthetic fragrances), polycyclic aromatic hydrocarbons, and organophosphate flame retardants, showing log BAFs up to 6.6. Such values were slightly higher in D. ramea than A. calycularis, but not statistically significant differences were observed (p-value > 0.05). Further research is encouraged to assess possible damage to cold-water coral species exposed to multiple contaminants.

Enhanced pollution control using sediment microbial fuel cells for ecological remediation.

Sediment Microbial Fuel Cell (SMFC) technology is an innovative approach to facilitate the degradation of sedimentary organic matter by electroactive microorganisms, transforming chemical energy into electrical energy and modulating the redox potential at the sediment-water interface, consequently controlling the release of endogenous pollutants. The synergistic effects of various environmental factors and intrinsic conditions can significantly impact SMFC performance. This review provides a comprehensive overview of SMFC development in research and application for water environment treatment and ecological remediation, a perspective rarely explored in previous reviews. It discusses optimization strategies for SMFC implementation, emphasizing advancements in novel or cost-effective electrode materials, the dynamics of microbial communities, and the control of typical pollutants. The review suggests a virtuous cycle path for SMFC development, highlighting future research needs, including integrating cross-disciplinary approaches like artificial intelligence, genomics, and mathematical modeling, to enhance the deployment of SMFC in real-world environmental remediation.

Exploring the combined toxicity of boron nitride nanosheets, cadmium and natural organic matter on Daphnia magna

The increase in anthropogenic activities has led to the release of numerous chemicals and pollutants into aquatic ecosystems, raising significant concerns for water quality and health. Among the emerging issues is the interaction between pollutants and nanomaterials (mixture effects). In this work, it was studied the combined toxicity of boron nitride nanosheets (BNNS) and cadmium (Cd2+) incorporating the influence of natural organic matter (NOM) to enhance ecological relevance for the first time. Colloidal stability studies showed that BNNS is highly unstable, aggregating and precipitating over time in mineral reconstituted water. However, the addition of natural organic matter stabilizes BNNS. Acute toxicity results showed that this material has a good biocompatibility with D. magna, not causing acute toxic effect (immobility) even at high concentration (100 mg L−1). Moreover, when combined with cadmium, BNNS exhibited a "Trojan horse" effect, enhancing Cd2+ toxicity by facilitating its uptake at 1 mg L−1. 48h-EC50 values of Cd2+ and BNNS+Cd2+ were 0.21 and 0.14 mg L−1, respectively. Nevertheless, NOM (10 mg L−1) mitigated this combined toxicity effect after 48h of exposure. These findings provide novel insights into nanomaterial-pollutant interactions linked to toxicological effects in aquatic environments, contributing to the risk assessment for the safe and sustainable development of the emerging boron nitride nanomaterials and novel products.

Chemical mixtures of mercury, PCBs, PFAS/PFOS, and pesticides in freshwater fish in the US and the risks they pose for fish consumption

Freshwater fish are important food sources that also pose risks to human and wildlife health because of the bioaccumulation of environmental chemicals in their tissues. Although most studies, fish consumption advisories, and regulations focus on individual contaminants, fish consumers are exposed to mixtures of chemicals, including legacy contaminants and contaminants of emerging concern, that can have combined effects. Chemicals of emerging concern represent one source of hazard, but legacy contaminants can still pose threats to fish consumers due to their persistence in the environment. We investigate the following questions: 1) Do different chemicals correlate with one another in fish tissue, and if so, how? 2) How do levels of different chemicals in fish tissue vary by time and location? and 3) How do observed chemical levels compare with risk-based screening levels? Using several national data sources established and maintained by the US Environmental Protection Agency (NRSA, NCCA-GL, GLENDA, and NLFTS), this study examines the co-occurrence of chemicals in freshwater fish in lakes, ponds, streams, and rivers in the US. We determine that organic contaminants correlate with one another, but generally not with mercury; organic chemicals have declined over time, but mercury has not; and fish concentrations of legacy contaminants-even those banned for decades-continue to exceed risk-based screening levels. Despite some successes in curtailing release of pollutants, some contaminants in fish tissue have not declined and legacy and emerging pollutants continue to pose risks to fish consumers in the US. Correlations between chemicals in fish tissue suggest that exposures to mixtures is prevalent in the US but that organic contaminants do not generally correlate with mercury-noteworthy particularly since fish consumption advisories in the US are frequently driven by the level of mercury, and do not account for exposure to multiple contaminants. While programs such as the National Aquatic Resource Surveys (NARS) Program seek to systematically monitor contaminants in fish tissue and other environmental indicators, continuous support from the US federal government is required to sustain this monitoring. Moreover, greater legislative and regulatory efforts are required at both the state and federal levels to reduce continuing sources and ongoing contamination.

Gasification-MILD combustion technology with ash-sludge recirculation for reducing multi-phase net dioxin discharges from a waste incineration.

This study addresses the challenge of reducing "net" toxic pollutant discharge, specifically dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), while minimizing the energy consumption and costs associated with detoxification. Our research focuses on reintroducing fly ash and scrubber sludge (ASR) into a hazardous waste thermal treatment system equipped with gasification-intense low oxygen dilution (GASMILD) and an advanced air pollution control system (APCS). This approach yielded a remarkable PCDD/F removal efficiency exceeding 99.9% for both mass and toxic equivalent (TEQ), achieving a net destruction of PCDD/Fs within the system. The success can be attributed to the ASR material's richness in ultrafine particles, which act as nucleation cores during combustion, promoting particle growth and enhancing the capture of PCDD/Fs in the APCS. This leads to a significant reduction (over 93%) in both PCDD/F mass and World Health Organization-toxic equivalent (WHO-TEQ) concentration in the flue gas. While a phase transition of gaseous PCDD/Fs within the APCS caused a shift in the particle size distribution towards larger particles, the overall PCDD/F mass concentration in the stack emissions remained lower with ASR. Notably, the reintroduced PCDD/Fs tend to deposit in the nasal region of the respiratory tract, potentially reducing the health risks associated with deeper lung deposition. This research demonstrates the effectiveness of ASR in achieving net PCDD/F destruction within a GASMILD combustion system, offering a promising strategy for cleaner and more sustainable waste management practices. From a managerial perspective, this approach provides a cost-effective solution for PCDD/F mitigation, contributing to reduced emissions and improved public health.

Comprehensive evaluation of groundwater quality in population-dense and extensive agricultural regions and study on its relationship with agricultural production and human activities.

Extensive agricultural regions commonly face issues of poor groundwater management, non-standard agricultural production practices, and unordered discharge of domestic pollution, leading to a continuous decline in groundwater quality and a sharp increase in risks. A comprehensive understanding of groundwater conditions and pollution is a crucial step in effectively addressing the water quality crisis. This study employs the Comprehensive Water Quality Index, Irrigation parameter, and Pollution Index to comprehensively investigate the groundwater quality in a typical agricultural area in Shandong, China, and assesses the suitability of groundwater for irrigation and the risks to human health. Furthermore, multivariate statistical analysis methods are utilized to analyze the relationship between groundwater quality and agricultural production and human activities. The results of the comprehensive quality evaluation indicate that the groundwater in the study area is primarily characterized as weakly alkaline hard freshwater and slightly brackish water, with a hydrochemical type of HCO3-Ca. 42% of the groundwater is unsuitable for drinking, with the main pollutants being TDS, TH, F-, and NO3-. The shallow groundwater level and high soil permeability provide favorable conditions for pollutant migration. Residual Sodium Carbonate (RSC) and Potential Salinity (PS) indicate that 37% of the water samples have excessive bicarbonate levels and 5% have excessive salinity, making them unsuitable for irrigation. Nitrate poses non-carcinogenic risks to all three age groups. Multivariate analysis results show that agricultural pollution dominates in the groundwater, with major pollutants including SO42-, NO3-, COD, NH4-N, F-, etc. Domestic pollution mainly increases the concentrations of ions such as Ca2+, Na+, Mg2+, and also contributes to Cl- and NO3-. The findings of this study contribute to enhancing the rational utilization of groundwater quality in agricultural areas, standardizing agricultural production activities, and promoting the sustainable development of green agriculture.

Research of Water Pollution Based on Vine Copula Function in the Min River Basin, China

At present, the protection of the ecological water environment in Min River Basin has achieved certain results, but certain problems remain that require strengthened ecological protection and environmental management. Understanding the connection between water quality factors and exploring the factors affecting water quality are of great significance in determining the pollution status of watershed water and promoting the comprehensive management of watershed water quality. In this study, water quality data collected from 20 monitoring stations were used to qualitatively and quantitatively evaluate the quality of waters in the watershed. Then, the joint distribution of water quality factors was constructed using the C-vine copula method, and the main influencing factors of water quality were explored using the D-vine copula structure. This approach facilitated the current study of the integrated status of water quality pollution. The results and conclusions of the current study are as follows: (1) A total of four tree structure levels were constructed using the model. The indicators with the strongest correlation with water quality were total phosphorus during the flood season and total nitrogen during the dry season. (2) After the introduction of condition variables, dissolved oxygen exhibited the strongest correlation with the rest of the variables during the flood season. Moreover, the permanganate index was most strongly correlated with the rest of the variables during the dry season. (3) Pollution discharges and industrial structure had a large impact on water quality. In particular, urban wastewater discharge, the share of primary industry, and per capita GDP were key drivers of water quality. Reducing urban wastewater discharge and optimizing industrial structure are beneficial for improving water quality. The research results have certain guiding significance for allowing Fujian to achieve water environment protection and sustainable development.

Comparing space-based to reported carbon monoxide emission estimates for Europe's iron and steel plants

Abstract. We use satellite observations of carbon monoxide (CO) to estimate CO emissions from European integrated iron and steel plants, the continent's highest-emitting CO point sources. We perform analytical inversions to estimate emissions from 21 individual plants using observations from the TROPOspheric Monitoring Instrument (TROPOMI) for 2019. As prior emissions, we use values reported by the facilities to the European Pollutant Release and Transfer Register (E-PRTR). These reported emissions vary in estimation methodology, including both measurements and calculations. With the Weather Research and Forecasting (WRF) model, we perform an ensemble of simulations with different transport settings to best replicate the observed emission plumes for each day and site. Comparing the inversion-based emission estimates to the E-PRTR reports, nine of the plants agree within uncertainties. For the remaining plants, we generally find lower emission rates than reported. Our posterior emission estimates are well constrained by the satellite observations (90 % of the plants have averaging kernel sensitivities above 0.7) except for a few low-emitting or coastal sites. We find agreement between our inversion results and emissions we estimate using the cross-sectional flux (CSF) method for the seven most strongly emitting plants, building further confidence in the inversion estimates. Finally, for four plants with large year-to-year variability in reported emission rates or large differences between the reported emission rate and our posterior estimate, we extend our analysis to 2020. We find no evidence in either the observed carbon monoxide concentrations or our inversion results for strong changes in emission rates. This demonstrates how satellites can be used to identify potential uncertainties in reported emissions.

Influence of goethite on the fate of antibiotic (tetracycline) in the aqueous environment: Effect of cationic and anionic surfactants.

Over the last decades, the release and occurrence of organic pollutants in aquatic systems have become a major global concern due to their bioaccumulation, toxicity, and adverse effects on the ecosystem. Tetracycline (TC), a widely used antibiotic, is often found at high concentrations in the aqueous environment and tends to bind with the natural colloids. Post-COVID-19 pandemic, the release of surfactants in the environment has increased due to the excessive use of washing and cleaning products. This study systematically investigated the interaction of goethite with TC in the absence and presence of anionic (sodium dodecyl sulfate, SDS) and cationic (cetyltrimethylammonium bromide, CTAB) surfactants. The impact of various environmental parameters like pH, ionic strength, temperature, and organic matter was also studied. It was observed that SDS has drastically increased TC sorption onto goethite from 11mg/g to 19mg/g, while CTAB had the opposite effect. To delineate the goethite-TC interaction mechanisms, FTIR with two-dimensional correlation analysis (2D-COS) was performed. The pH of the solution was crucial in the presence of SDS, while ionic strength did not affect the interaction process. The sorption process was endothermic, as evidenced by the increase in sorption capacity with the rise in the temperature. The presence of organic matter hinders the sorption of TC onto goethite, which is also observed in river water where the organic content is very high. Overall, our study helps to predict the fate of organic pollutants like antibiotics in aqueous environments in the coexistence of surfactants and iron oxyhydroxides.

Spatial and temporal distribution characteristics and source apportionment of biogenic elements using APCS-MLR model in the main inlet tributary of Danjiangkou Reservoir.

Danjiangkou Reservoir has been widely concerned as the water source of the world's longest cross basin water transfer project. Biogenic elements are the foundation of material circulation and key factors affecting water quality. However, there is no comprehensive study on the biogenic elements in tributaries of Danjiangkou Reservoir, hindering a detailed understanding of geochemical cycling characteristics of biogenic elements in this region. Guanshan River, one of the main tributaries that directly enter the Danjiangkou Reservoir, was token as the research object. Spatiotemporal distribution characteristics of basic water quality parameters and biogenic elements were studied. Water quality was comprehensively evaluated through water quality index (WQI). Absolute principal component score-multiple linear regression (APCS-MLR) model was adopted to explore the main sources of biogenic elements. Results showed that, in terms of season, the concentrations of total nitrogen (TN), total phosphorus (TP), and dissolved organic carbon (DOC) were significantly higher in wet season than in dry season, while no significant differences were found for dissolved inorganic carbon (DIC) and dissolved silica (DSi). Spatially, the concentrations of dissolved carbon, DIC, TN, and TP in the middle and lower reaches were higher than that in the upstream. DOC concentration peaked in the middle reaches, while DSi showed higher concentrations in the upstream. WQI values indicated that the river water quality was between good and excellent, although the water quality in wet season was slightly worse than that in the dry season. PCA extracted five potential sources, which accounting for 84.12% of the total variance, including rock weathering, mixed source of sewage discharge and agricultural non-point source pollution, dissolved soil CO2, seasonal factor, and agricultural non-point source pollution. These sources contributed 38.96%, 12.33%, 13.54%, 23.95%, and 11.21% to river water quality parameters, respectively. Strengthening the monitoring of biogenic elements, controlling pollutant discharge, and exploring the relationship between biogenic elements and other pollutants are important for the water environment management in this basin.

The Evolution of Policies for the Resource Utilization of Livestock Manure in China

With the continuous development of animal husbandry, the harmless handling and resource utilization of livestock manure has gradually become a bottleneck problem in sustainable agriculture and livestock production in China. This study evaluates the policies related to manure handling and utilization in different economic development periods in China. The decreased pollutant discharge from livestock manure indicates the effectiveness of the strategy aiming to encourage the construction of manure treatment facilities and resource utilization in cropland and to establish a sound legal system for pollutant discharge. New policies and measures should be introduced to promote the coupling of intensive livestock breeding and crop planting, with the direction of nutrient management planning and the incorporation of a service platform for the resource utilization of manure. Technological innovation in green livestock breeding should be supported by policies to achieve source reduction in pollutants in breeding waste.

Amalur EIS: a system for calculating the environmental impacts of industrial sites from E-PRTR records

This article presents Amalur EIS (https://www.amalur-eis.eus/), an Environmental Information System that estimates environmental impacts using data sourced from the European Pollutant Release and Transfer Register database (E-PRTR). The system uses data on the releases into land, air and water of 31,556 European industrial facilities for the period 2007–2021. Amalur EIS calculates environmental impacts of industrial releases using 31 life cycle impact assessment methods (LCIA) and covering 78 of the 91 pollutants regulated by the PRTR Protocol. The system has been constructed using a two-layer software infrastructure: (i) a data layer supported by a relational database built in Postgres and (ii) a presentation layer built in Tableau, so it provides user-friendly access to the information. For an illustrative analysis of the tool, the EF 3.0 LCIA method recommended by the European Commission was used, including normalisation and weighting steps for a better comparison. The analysis concludes that the climate change impact category contributes the most (68.6%) to the total impacts, while the largest contributor from an economic activity perspective is the energy sector (59.5%). Geographically, both elements coincide in the German regions of Düsseldorf, Köln and Brandenburg, resulting in the concentration of the largest impacts at the European regional level. In fact, Germany is the country with the highest impact (20.3% of total). Beyond this analysis, Amalur EIS is poised to be a valuable tool for tracking the transition towards sustainability, particularly in Europe.

Distribution, sources and risk assessment of heavy metals in Yangshan port and its adjacent sea areas

Heavy metals play an important role in marine ecosystems, but excessive heavy metals can harm aquatic life and human health. The Yangshan Port is located near an important agricultural and fishing area in China, with rich fishery resources. However, there is a lack of research on the impact of heavy metal pollution on local fishery and environment. This study assessed the concentrations of seven metals (Cu, Zn, Pb, Cr, Cd, As, Hg) in the water, sediments and two organisms (fish and benthic organisms) of Yangshan Port, aiming to get a comprehensive information about the heavy metal pollution in Yangshan Port and its adjacent sea areas. The results showed that the concentration of heavy metals in the sediments was higher than that observed in the water. The concentrations of heavy metals in water and sediments were influenced by human activities. The main reason for this regional distribution difference was human factors such as industrial wastewater discharges, household pollution, and agricultural and fishery discharges, followed by various natural factors, such as organic content and sulfate, as well as hydrodynamic self-disturbance. It is worth noting that As is affected not only by emissions from land-based sources, but also by riverine inputs and human marine engineering activities. The ecological risk indicated that two of seven metals (As and Hg) posed a risk to the marine environment in this region. In addition, the content and accumulation level of heavy metals in benthic organisms was significantly higher than that in fish. Human health risk assessments showed that the heavy metal posed a potential carcinogenic risk to human health, particularly to children. Overall, the health risks from seafood intake by humans were low, with As having the greatest impact on human health, and metal concentrations being the most sensitive factor affecting metal health risk assessment, with As being the most sensitive element. This study provided new insight into the heterogeneity of heavy metal pollution accumulation in the Yangshan Port and its adjacent sea areas and offered a scientific basis and favorable support for port ecological environment protection and prevention of heavy metal pollution-related ecological risks.

Occurrence, toxicity, ecological risk, and remediation of diclofenac in surface water environments: A review with a focus on China

Abstract Diclofenac (DCF) is a non-steroidal anti-inflammatory drug commonly used in healthcare, livestock, and pharmaceuticals and widely detected in surface water environments globally. Here, we reviewed the occurrence characteristics, migration pathways and aquatic toxicity of DCF in surface water environments. Asian and African populations are exposed to high concentrations of DCF (> 8000 ng L−1). Wastewater discharge, livestock, and industrial pollution are the primary factors influencing the concentration and distribution of DCF. Diclofenac can cause acute toxicity, oxidative stress, and other toxic effects on aquatic organisms. We focused on China and analyzed the ecological risks of DCF in surface water environments, presenting low risk in the south and high risk in the north, as well as low risk during the rainy season and high risk during the dry season. Finally, we discussed the removal methods for DCF and proposed the potential of metal-organic frameworks as a new material to replace conventional methods for DCF removal. This study comprehensively revealed the pollution status of DCF and the ecological risk it poses to surface water environments, providing a reference for the environmental management of DCF.

Analysis of the Biodegradability Index of Organic Matter in the Water of the Machangara River in Quito City

The evaluation of the water quality in rivers is essential to identify the impact of human activities and establish mitigation strategies. The aim of this project is to analyze the biodegradability index of organic matter in the water of the Machangara river in Quito city of Ecuador. It flows through some places of Quito such as “Las Cuadras”, “El Recreo”, “La Recoleta”, and “Nayon”. Through sampling in the aforementioned sectors, the parameters necessary for the calculation of biochemical (BOD), and chemical (COD) oxygen demand were analyzed, along with other physicochemical parameters such as turbidity and watercolor. In addition, a survey was conducted in the study areas in March 2023. The results showed a significant variability in the level of contamination among the sectors analyzed. A higher level of contamination was found in the areas of La Recoleta and El Recreo compared to Las Cuadras, and Nayon, which is attributed to direct discharges of pollutants from illegal pipes connected to both industries and households. The biodegradability index obtained suggests the need to implement chemical, and biological treatments for the efficient removal of organic and inorganic pollutants present in the river. The physicochemical analysis showed that the turbidity, and color of the water also correlated with the high levels of pollution observed, especially in the most affected sectors. The information gathered through interviews showed that the local population suffers directly from the negative effects of this contamination, manifesting symptoms such as headaches, nausea, vomiting, fatigue, lack of concentration, and depression, especially in children, and older adults. In conclusion, the results of this study highlight the need for immediate corrective measures, such as chemical, and biological treatments, to mitigate the environmental, and health impacts of the Machangara River and improve the quality of life of the affected population.

Complicated pollution characteristics (particulate matter, heavy metals, microplastics, VOCs) of spent lithium-ion battery recycling at an industrial level.

The recycling of spent lithium-ion batteries has become a common concern of the whole society, with a large number of studies on recycling management and recycling technology, but there is relatively little study on the pollution release during the recycling process. Pollution will restrict the healthy development of the recycling industry, which makes relevant research very significant. This paper monitored and analyzed the battery recycling pretreatment process in a formal factory, and studied the pollution characteristics of particulate matter, heavy metals, and microplastics under different treatment stages. In addition, the release characteristics of VOCs during pyrolysis were also studied. When the green pretreatment process was used, PM10 concentration in most processing units was below 100μg/m3, indicating that the overall pollution prevention and control effect in the workshop is well-done. Particulate matter in workshop contained a large amount of metal components, mainly Fe, Cu, Co, Mn, Ni, etc. Microplastics were widely distributed in ground dust, and small-size microplastics are suspended in the air for a long time because of Brownian motion. Collecting ground dust and particulate matters is beneficial for controlling the emission of microplastics. During thermal treatment, Ethylene carbonate and dimethyl carbonate in the electrolyte would enter the atmosphere, and a large amount of short chain hydrocarbons released together, forming VOCs pollution. This study summarized distribution characteristics of different pollutants in a battery recycling factory. The basic pollution data provided are beneficial for improving the recycling technology of spent lithium-ion battery.