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Microplastic (MP) environmental contamination has been widely studied in Mexico. However, the evaluation of the associated risk to MPs in environmental compartments is scarce. Therefore, this study addresses this issue using diverse indicators such as the Pollution Load Index (PLI), the Polymer Risk Index (PRI), and the Potential Ecological Risk Index (PERI). The results of a meta-analysis revealed high MP contamination levels in most of the studied compartments, which included marine and estuarine waters, beach sand, freshwater, sediments, and biota. Regarding the risk assessment indicators, PLIs indicated low (56%), dangerous (22%), moderate (12%), and high (10%) levels across compartments. Meanwhile, PRIs displayed concerning values, with 36%, 35%, 20%, and 9% exhibiting dangerous, high, moderate, and low levels, respectively. Thus, high PRI values emphasized the significant rise in MP pollution, largely attributed to high-hazard polymer compositions. Otherwise, PERIs showed low (56%), very dangerous (29%), moderate (6%), high (5%), and dangerous (4%) levels. Thus, the ecological risk in Mexico is widespread and mainly linked to MP abundance, polymer type, environmental matrix, and characteristics of organisms. This study represents the first attempt at MP ecological risk assessment in Mexico, providing crucial insights for developing mitigation strategies to address concerns about MP contamination. [Display omitted] • First study on MPs' ecological risk in Mexico's environmental compartments. • Spatial distribution of MPs in environmental matrices is widespread. • MP contamination levels were predominantly high in most environmental compartments. • MP risk in Mexico assessed with PLI, PRI, and PERI shows widespread results. • Ecological risk is tied to MP abundance, polymer type, matrix, and organism traits. [ABSTRACT FROM AUTHOR]

Wastewater treatment is an important topic for improving water quality and environmental protection, and artificial intelligence has become a powerful tool for wastewater treatment. This work provides research progress and a literature review of artificial intelligence applied to wastewater treatment based on the visualization of bibliometric tools. A total of 3460 publications from 2000 to 2023 were obtained from the Web of Science Core Collection database. The literature was analyzed from various aspects such as publications, journals, and authors. There are collaboration relationships among various countries, institutes, and authors. Keywords were analyzed in three directions "artificial intelligence", "wastewater treatment technology", and "pollutant types". Hot keywords were identified, including "support vector machine", "random forests", "membrane bioreactor", "photocatalytic degradation", and "antibiotics". Significant advancements were obtained in intelligent water quality monitoring, innovative material development, and energy cost optimization. Machine learning algorithms, such as Convolutional Neural Networks and Long Short-Term Memory, demonstrated remarkable capabilities in predicting process parameters, enhancing material performance, and optimizing energy utilization in wastewater treatment plants. Artificial intelligence applied to wastewater treatment is still in its primary stage, and with the rapid development of artificial intelligence, significant technical innovation in wastewater treatment can be anticipated in the near future. [Display omitted] • Bibliometric analysis of artificial intelligence in wastewater treatment (2000–2023) was conducted. • The most influential journals, countries, institutions, and authors were identified. • Research advances of artificial intelligence applied to wastewater treatment were discussed. • Activated sludge, nitrogen removal, and optimization are popular topics. • Big advance in intelligent monitoring, material development, and energy cost optimization. [ABSTRACT FROM AUTHOR]

In this work, we present an eight-month longitudinal study of wastewater-based epidemiology (WBE) in Ahmedabad, India, where wastewater surveillance was introduced in September 2020 after the successful containment of the first wave of COVID-19 to predict the resurge of the infection during the second wave of the pandemic. The study aims to elucidate the weekly resolution of the SARS-CoV-2 RNA data for eight months in wastewater samples to predict the COVID-19 situation and identify hotspots in Ahmedabad. A total of 287 samples were analyzed for SARS-CoV-2 RNA using RT-PCR, and Spearman's rank correlation was applied to depict the early warning potential of WBE. During September 2020 to April 2021, the increasing number of positive wastewater influent samples correlated with the growing number of confirmed clinical cases. It also showed clear evidence of early detection of the second wave of COVID-19 in Ahmedabad (March 2021). 258 out of a total 287 samples were detected positive with at least two out of three SARS-CoV-2 genes (N, ORF- 1 ab, and S). Monthly variation represented a significant decline in all three gene copies in October compared to September 2020, followed by an abrupt increase in November 2020. A similar increment in the gene copies was observed in March and April 2021, which would be an indicator of the second wave of COVID-19. A lead time of 1–2 weeks was observed in the change of gene concentrations compared with clinically confirmed cases. Measured wastewater ORF- 1 ab gene copies ranged from 6.1 x 102 (October 2020) to 1.4 x 104 (November 2020) copies/mL, and wastewater gene levels typically lead to confirmed cases by one to two weeks. The study highlights the value of WBE as a monitoring tool to predict waves within a pandemic, identify local disease hotspots within a city, and guide rapid management interventions. [Display omitted] • Eight-months of SARS-CoV-2 gene variations explicitly predicts 2nd COVID-19 wave. • 258 out of 287 wastewater samples were detected positive for SARS-CoV-2 genes. • WBE offers a lead time of 1–2 weeks for the preparedness of pandemic situation. • Model suggests that ORF 1 ab gene is the most effective marker gene in WBE study. • Gathered WBE data worldwide may now be subjected to several AI/ML based simulations. [ABSTRACT FROM AUTHOR]

Abstract Todos Santos is a coastal town located in Baja California Sur (Mexico), which has experienced an increase in tourist and agricultural activities during the last years. However, the Todos Santos aquifer is the sole source of freshwater supplied to populations. Therefore, the goal of this work is to investigate the processes that can cause groundwater salinity in this aquifer. The results of the chemical analysis performed in groundwater indicate 3 water groups: i) less mineralized waters of the recharge zones showing a strong interaction with silicate rocks; ii) transition-zone waters from alluvial sediments also reflecting silicate rock-water interaction; iii) the most mineralized waters located along the coastline reflecting seawater intrusion. Overall, the ionic composition and the salinity gradient of groundwater are in agreement with the topographic flow paths. Nevertheless, in wells located in the coastline, groundwater interacts with seawater and undergoes evaporation simultaneously, exponentially increasing the salinity beyond seawater composition. [ABSTRACT FROM AUTHOR]

Abstract The Water-Energy-Food Nexus (or WEF Nexus) is a conceptual framework for analysing and managing natural resources for life and sustainable development. It is well known that to produce food, water and energy are needed; to pump, treat or purify water, energy is needed; and energy production requires water. Under this statement, this paper presents an actual overview of the current state of the water-energy-food nexus in Latin American and The Caribbean countries. The analysis is divided in terms of water, energy and food production for each country. The proposed WEF Nexus index comprises three key indicators per sector, considering availability, access, and stability of sector's resources. The obtained results show that three sectors need more attention for future development, especially in the Caribbean countries. [ABSTRACT FROM AUTHOR]

Abstract The link between water, energy, and food has gotten more attention over the last years. The increased needs for water, energy and land resources, as well as the environmental degradation and, in some cases, scarce resources, have driven the search for strategies for sustainable development within the Water-Energy-Food (WEF) nexus concept. This paper presents an approach to assess water and power distribution grids for food production, based on WEF nexus approach, in order to support decision-making and guide the sustainable development, sensitive to the nexus policies. The proposed optimization model seeks to identify the optimal solution including economic, environmental and social aspects that satisfy the stakeholders. The model is applied to a case study in the Sonora desert, Mexico. The results show that the proposed methodology is a suitable tool to evaluate multiple scenarios for the decision-making process. [ABSTRACT FROM AUTHOR]

Abstract The evolution of several trace elements was evaluated in shallow groundwater of an agricultural area located in a semi-arid region of northeastern Mexico. A Principal Component Analysis (PCA) was performed to assess the geochemical processes controlling the distribution and mobility of these elements. Five principal components (PC) were significant. PC1 indicates that Ti and Si come from soil/silicate weathering. Sulfate, Mo and U were grouped in PC2, indicating the same redox behavior. PC3 shows similar sources for Rb and Cs (halite weathering), whereas the PC4 grouped the immobile elements Cd and Pb. The correlation found between Zn and Cu in PC5 indicates a similar behavior of both elements during the weathering and transport. Although the measured trace elements were detected in groundwater, their concentrations were lower than the guidelines values for safe drinking water proposed by international organizations, suggesting that these elements do not pose any significant threat to consumers. [ABSTRACT FROM AUTHOR]

Abstract The increasing presence of chemicals and pharmaceuticals in rivers, lakes, and groundwater among others, represents a latent threat both to ecosystems and to human health. Conventional treatment methods for water hardly eliminate these pollutants, which are usually dissolved in low concentrations (μgL−1 or ngL−1). Therefore, the use of nanomaterials represents a viable alternative to eliminate them. Titanate nanotubes have been successfully used in adsorption of organic dyes as well as heavy metals, however, their use as an adsorbent of pharmaceuticals and other organic pollutants has been scarcely studied. In this work, unmodified titanate nanotubes as well as modified titanate nanotubes by using a surfactant, were synthesized and characterized to study the adsorption of six organic pollutants of interest through first and second order kinetic models, as well as, adsorption isotherms of Freundlich and Langmuir. The synthesized nanotubes showed good efficiency for the adsorption of persistent organic compounds, reaching a maximum adsorption percentage of 83%, 78%, 54%, 43%, 30% and 47% for 2,4,6-trichlorophenol, oxytetracycline, 2,4-dichlorophenol, tolazamide, captopril, and metformin respectively. Moreover, removal of pollutants was also successfully carried out in groundwater samples. [ABSTRACT FROM AUTHOR]

Most of the studies regarding aromatic hydrocarbon degradation by ozone focus on individual treatment. Hence, two aromatic hydrocarbons, ethylbenzene (ETB) presented in water and fluorene (FL) distributed in soil, were selected to be eliminated simultaneously in water, soil, and air using ozone. In this study, the effect of the physicochemical properties of ETB and FL, the distribution of FL on sandy and agricultural soils, and the influence of the presence of moisture in both soils were analyzed. The chemical composition of the agricultural soil (mainly metal oxides) enhanced the FL degradation by the possible catalytic ozone decomposition into reactive species, such as •OH, O 2 •−, H 2 O 2 , O 3 •−, and O • , which reduced its treatment time 4.5-fold in this solid matrix compared to the sandy soil. Moreover, the moisture liberated from water by the gas flow and adsorbed on the soil bed (up to 0.33% at 180 min) reduced the ozonation time 2-fold in the agricultural and sandy soils, due to the •OH formation. Contrary to FL, the rapid elimination of ETB (< 20 min) in both soils did not allow to observe the possible effect of reactive species generation on ETB decomposition due to the low amount of moisture accumulated during this time (<0.06%). The proposed simultaneous ozonation scheme permitted to achieve up to 96% and 100% of the ETB and FL decomposition. Some identified by-products, such as maleic, malonic, oxalic, and formic acids, suggest that ozone and possible reactive species formed on the soil surfaces reacted with both compounds, leading to non-toxic simple by-products with their partial mineralization (≈80%), which was proven by a toxicity evaluation (phytotoxicity and eco-toxicity). The rapid and efficient simultaneous ozonation of aromatic hydrocarbons in water, soil, and air (only ETB) proves the feasibility of ozone to treat different organic pollutants in more than one phase. [Display omitted] [ABSTRACT FROM AUTHOR]

Contaminant vulnerability in the critical zones like groundwater (GW)-seawater (SW) continuum along the entire Gujarat coast was investigated for the first time through an extensive water monitoring survey. The prime focus of the study was to evaluate whether or not: i) seawater intrusion induced metal load translates to toxicity; ii) in the coastal groundwater, metal distribution follows the pattern of other geogenic and anthropogenic contaminants like NO 3 - and F-; and iii) what future lies ahead pertaining to metal fate in association with saturation conditions of the coastal aquifers. The spatial distribution of contaminants depicts that the Gulf of Khambhat area is highly contaminated. Ecological risk assessment (ERA) indicates that the Gujarat coast is experiencing a high ecological risk compared to the southeast coast of India. Investigation results revealed that metals, pH, NO 3 , and CO 3 are more vulnerable at the SW-GW mixing interface. An increase in pH is reflected in fewer ionic species of metals in the GW. Salinity ingress due to seawater intrusion (SWI) reduces the toxicities of all trace metals except Cu, attributed to the increase of Ca in GW, leading to dissociation of CuCO 3. Reactive species are dominant for Zn and Cd; and M-CO 3 ligands are dominant for Cu and Pb owing to the undersaturation of dolomite and calcite in the aquifer system. SWI tends to increase the metal load but the toxicity of metals varies with the density of industries, anthropogenic activities, changes in the mixing-induced saturation conditions, and intensive salt production across the coast. Multivariate analysis confirmed that the hydrogeochemical processes change due to GW-SW mixing and dictates over natural weathering. The ecological risk index (ERI) for the Arabian sea is experiencing moderate (300 ≥ ERI>150) to high ecological risk (ERI >600). Children population is likely to encounter a high health risk through ingestion and dermal exposure than adults. Overall, the study emphasizes the complexity of toxicity-related health impacts on coastal communities and suggests the dire need for frequent water monitoring along the coastal areas for quick realization of sustainable development goals. [Display omitted] • Seawater intrusion increases metal load but does not necessarily translate to toxicity. • In the coastal groundwater, metal distribution differs the pattern of NO 3 − and F−. • M2+ and CO 3 2− forms were dominant for Zn & Cd; and Cu & Pb, respectively. • Higher intrusion seems to decrease free ionic metals but has no profound effect on pH. • Undersaturation of Dolomite & Calcite reasons the dominance of MCO 3 forms. Capsule: Seawater intrusion increases metal load but does not necessarily translate to toxicity. [ABSTRACT FROM AUTHOR]

During the last decades, metropolitan areas with a large population and economic size have mushroomed, modifying the urban geography and natural environment. Along with the rising of megacities, highly engineered basins have been created, providing resource security regarding water and energy. The coastal Guandu River basin in Brazil represents an artificial basin that has been heavily intervened for decades. The basin receives almost ∼80% of the water by transfers from the Paraiba do Sul River Basin System and has an associated hydroelectric complex that generates power for the national network. It is the primary source of water and energy for the Rio de Janeiro Metropolitan Area, home to ∼13 million people. Recently, water availability for this region has been jeopardized by drought conditions due to changing rainfall patterns and competition for water resources with other users such as Sao Paolo Metropolitan Area. This study focuses on the development of an optimization framework (WANAB model) for water resources management at the macroscopic level in the Guandu Basin to guarantee economic viability and water resources sustainability. The model incorporates parameters and equations for hydrological, and engineered water and hydropower processes to determine the optimal water allocation network. Also, a multi-criteria analysis is proposed to evaluate the water availability considering different scenarios. The results show that through optimization, it is possible to have a water availability of up to ∼24 m3/s in the Guandu River basin by integrating elements such as water storage systems, grey and blackwater treatment plants with capacities up to ∼39 m3/s and ∼9 m3/s, respectively. The results show that it is possible to reach a water availability of 21 m3/s in the scenario, considering the reduction of water transfers from outside the basin due to climate change. However, the major impact is observed in the hydropower generation, decreasing from ∼2270 GWh/y to ∼1950 GWh/y. The WANAB model represents a decision-making and policy tool for optimizing water allocation networks and may be adapted for other highly engineered basins. [Display omitted] • Optimal planning mitigates the impact of the water crisis in Rio de Janeiro. • Strategic scheduling is mandatory for water conservation in highly altered basins. • Optimization demonstrates feasible solutions in reduced water transfer scenarios. • Integrating optimal water infrastructure and storage can recover up to ∼24 m3/s. [ABSTRACT FROM AUTHOR]

The photocatalytic efficiency of BiVO 4 was enhanced through rare-earth doping (Gd3+). The effect of different concentrations of Gd3+ was evaluated through the decomposition of bisphenol A in water. To better understand the photocatalytic properties of the synthesized photocatalysts, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller (BET) method were applied. It was found that 4% of Gd3+ in molar mass showed the best photocatalytic efficiency. Decomposition of bisphenol A, bisphenol S, and bisphenol AF was studied using the photocatalyst with the optimal concentration of Gd3+, reaching decomposition percentages up to 77.02% ± 2.16, 44.36% ± 2.74%, and 74.11% ± 5.09, respectively after three hours reaction. Reactive species were identified by scavenging tests and additionally, kinetic studies were performed. A decomposition pathway was proposed for the three studied pollutants. The synthesized Gd3+ doped BiVO 4 photocatalysts demonstrated to be a promising alternative for the efficient degradation of disrupting endocrine compounds such as bisphenol A analogs present in water using LED visible light as an eco-friendly irradiation source. [Display omitted] • Visible-light driven Gd3+ doped BiVO 4 was prepared by thermal synthesis. • Optimal dopant concentration was found to be 4% of Gd3+ in molar mass. • A visible-LED lamp was used during photocatalysis as an eco-friendly light source. • •O 2 - were the main reactive species in photocatalytic removal of BPA, BPS, and BPAF. [ABSTRACT FROM AUTHOR]

The identification of nitrate (NO 3 −) sources and biogeochemical transformations is critical for understanding the different nitrogen (N) pathways, and thus, for controlling diffuse pollution in groundwater affected by livestock and agricultural activities. This study combines chemical data, including environmental isotopes (δ2H H2O , δ18O H2O , δ15N NO3, and δ18O NO3), with land use/land cover data and a Bayesian isotope mixing model, with the aim of reducing the uncertainty when estimating the contributions of different pollution sources. Sampling was taken from 53 groundwater sites in Comarca Lagunera, northern Mexico, during 2018. The results revealed that the NO 3 − (as N) concentration ranged from 0.01 to 109 mg/L, with more than 32% of the sites exceeding the safe limit for drinking water quality established by the World Health Organization (10 mg/L). Moreover, according to the groundwater flow path, different biogeochemical transformations were observed throughout the study area: microbial nitrification was dominant in the groundwater recharge areas with elevated NO 3 − concentrations; in the transition zones a mixing of different transformations, such as nitrification, denitrification, and/or volatilization, were identified, associated to moderate NO 3 − concentrations; whereas in the discharge area the main process affecting NO 3 − concentrations was denitrification, resulting in low NO 3 − concentrations. The results of the MixSIAR isotope mixing model revealed that the application of manure from concentrated animal-feeding operations (∼48%) and urban sewage (∼43%) were the primary contributors of NO 3 − pollution, whereas synthetic fertilizers (∼5%), soil organic nitrogen (∼4%), and atmospheric deposition played a less important role. Finally, an estimation of an uncertainty index (UI90) of the isotope mixing results indicated that the uncertainties associated with atmospheric deposition and NO 3 −−fertilizers were the lowest (0.05 and 0.07, respectively), while those associated with manure and sewage were the highest (0.24 and 0.20, respectively). Image 1 • Sources, transformations and contributions of nitrate pollution in groundwater investigated. • Thirty-two percent the samples exceeded the WHO limit for safe drinking water. • Mainly the application of manure and sewage leaks drove the increase of nitrate concentration. • Mixing process among evaporated soil water and recirculated water from irrigation identified. • Different nitrate transformation processes in recharge, transition and discharge areas. The combined approach estimated a number of nitrate pollution sources and transformation processes in groundwater, whereby manure and sewage leakages were the main drivers. [ABSTRACT FROM AUTHOR]

• Gd3+ doped BiVO 4 photocatalyst was obtained by thermal method. • UVA-LED lamp was used as an eco-friendly light source in photocatalytic treatments. • 4 of the studied PhACs showed high photocatalytic removal from wastewater effluent. • Photocatalytic inactivation of bacteria present in wastewater effluent was studied. • Enterococci were the most sensitive bacteria to photocatalytic treatment. In this study, gadolinium doped bismuth vanadate powders were synthesized, characterized, and tested as a potential photocatalyst for the removal of pharmaceutically active compounds (PhACs) and bacterial inactivation in a real wastewater effluent using UVA as irradiation source. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies revealed that the bismuth vanadate system was successfully doped with 4% of gadolinium in molar mass leading to the formation of a heterostructured photocatalyst. Up to 98.3 % of diclofenac was removed from pure water after 120 min through photocatalysis. However, the photocatalytic performance of the photocatalyst on wastewater effluent was rather variable due to the complexity of the matrix where 22 different PhACs were detected by means of Ultra Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry (UPLC-QqQ-MS/MS). High photocatalytic removal efficiency (80–100%) was observed for some of the studied PhACs (e.g. naproxen and furosemide) whereas moderate efficiency (40–70%) was observed for others (e.g. acetaminophen and azithromycin) after 180 min (UVA dose = 139.5 Wh m−2, t 30W = 279 min-1). Some of the studied PhACs like clarithromycin and Ibuprofen showed poor removal efficiency (< 30 %). In disinfection tests, Total coliforms, Escherichia coli, Enterococci , and Klebsiella pneumoniae showed inactivation after direct UVA LED photolysis. Nevertheless, higher inactivation was achieved for Enterococci in the presence of the synthesized photocatalyst showing an increase of 41.1 % in k max. [ABSTRACT FROM AUTHOR]

• Bi 2 O 3 /rGO/MoOx Z-scheme synthesized by a mixed hydrothermal and wet-chemical route. • Optimal Bi 2 O 3 :GO weight ratio was 300:1 in Rhodamine B degradation. • Synthesized composite has good photocatalytic activity under UV and visible light. • Degradation of organic pollutants in groundwater under visible light was achieved. A series of Bi 2 O 3 /rGO/Mo n O 3n-1 all-solid-state ternary Z-scheme were successfully synthesized by a mixed hydrothermal and wet-chemical route. The new materials are highly efficient under visible-light irradiation for the degradation of rhodamine B, bisphenol A, and acetaminophen and it was shown that the best performing composite was able to degrade up to 77 % of acetaminophen in groundwater samples. The synthesized materials were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Powder Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Nitrogen Adsorption-Desorption Isotherm and UV–vis Diffuse Reflectance spectroscopy. It was found that the presence of rGO plays an important role in the material since it helps in delaying the recombination time of photogenerated electron/hole (e−/h+) pairs, greatly improving the photocatalytic activity of Bi 2 O 3. The excellent photocatalytic activity under visible-light irradiation of Bi 2 O 3 /rGO/Mo n O 3n-1 makes it a promising material for the degradation of emerging contaminants in groundwater systems. [ABSTRACT FROM AUTHOR]

To attain sustainable development in Latin Ameica and the Caribbean, where there is a strong dependence on commodity and food price development, priority attention towards energy, water, and food security is critical. In this literature and data analysis, we examined the baseline and trends of resource security based on the Water-Energy-Food Nexus concept. A performance index was developed to evaluate the progress in water, energy, and food security of the region, and a nexus-based index was developed to evaluate the inter-linkages of these resources. Finally, critical issues and challenges for sustainable development were addressed. Results showed that an unprecedented amount of infrastructure is needed to address increasing energy consumption. Emphasis should be placed on gradually replacing high carbon-sources that produce electricity with low carbon-energy systems and clean power production. Results also showed that water scarcity, given unequal distributions of rainfall, will be aggravated by changing climate conditions; improvements in water governance as well as water and sanitation provisions are needed. The region is a net exporter of food, at the expense of water availability and greenhouse gas emissions, and suffers from structural constraints. It is important to foster novel agricultural practices and sustainable food systems. • Current trends demand urgent attention of energy, water and food security in LAC. • An unprecedented amount of new energy infrastructure needed for the next decades. • Need to change gradually from high to low carbon energy systems/clean power. • Food and energy markets are at the expense of water availability and GHG emissions. • WEF Nexus approach not yet incorporated the in the design of countries' policies. [ABSTRACT FROM AUTHOR]

The widespread presence of arsenic (As) and fluoride (F−) in groundwater poses substantial risks to human health on a global scale. These elements have been identified as the most prevalent geogenic contaminants in groundwater in northern Mexico. Consequently, this study aimed to evaluate the human health and ecological risks associated with the content of As and F− in the Meoqui-Delicias aquifer, which is in one of Mexico's most emblematic irrigation districts. Concentrations of As and F− were measured in 38 groundwater samples using ICP-MS and ion chromatography, respectively. Overall, these elements showed a similar trend across the aquifer, revealing a positive correlation between them and pH. The concentration of As and F− in the groundwater ranged from 5.3 μg/L to 303 μg/L and from 0.5 mg/L to 8.8 mg/L, respectively. Additionally, the levels of As and F− surpassed the established national standards for safe drinking water in 92% and 97% of samples, respectively. Given that groundwater is used for both agricultural purposes and human activities, this study also assessed the associated human health and ecological risks posed by these elements using Monte Carlo simulation and Species Sensitivity Distribution. The findings disclosed a significant noncarcinogenic health risk associated with exposure to As and F−, as well as an unacceptable carcinogenic health risk to As through water consumption for both adults and children. Furthermore, a high ecological risk to aquatic species was identified for F− and high to medium risks for As in the sampling sites. Therefore, the findings in this study provide valuable information for Mexican authorities and international organizations (e.g., WHO) about the adverse effects that any exposure without treatment to groundwater from this region represents for human health. [Display omitted] • As and F− in groundwater exceeded Mexican drinking standards in 92% and 97% of cases, respectively. • Probabilistic model suggests an 82% chance for adults, 95% for children to exceed safe As levels. • A high ecological risk to aquatic species was identified for F- and high to medium risks for As. • Excessive As and F- in drinking water linked to cancer, cognitive issues, posing widespread health risks. [ABSTRACT FROM AUTHOR]

In complex aquifer systems subject to intensive exploitation it is important to investigate hydrogeochemical processes in the components to understand the hydrodynamics of groundwater. In this respect, understanding the hydrochemical mechanisms of water-rock interactions and mixing processes eventually leads to the development of appropriate strategies for a sustainable groundwater management. In this study, we analyze water-rock interactions processes of the so-called Anáhuac groundwater system underlying part of the Mexico Valley comprising Mexico City and its suburbs. This intensively exploited system has four flow components: 1) local flow, 2) intermediate flow, 3) cold regional flow, and 4) hot regional flow. This is studied using inverse geochemical models, which consider uncertainties of analytical data and constraints from thermodynamic stability diagrams, speciation-solubility models, and petrographic data. Three representative modeling sections were selected for the implementation of the mass-balance approach. The general conceptual model in two sections suggests that rainwater infiltrates the subsoil and begins to dissolve CO 2 in the unsaturated zone; by reaching the saturated zone it reacts with silicate minerals of the host rock producing the final chemical composition of waters. On the other hand, the third section shows mixing as the main groundwater process, as well as water-rock interactions. In general, the identified processes of water-rock interaction are dissolution of CO 2 , dissolution of calcite, gypsum, and halite, Ca/Na ion-exchange, and weathering of silicate minerals such as biotite, muscovite, plagioclase, epidote and pyroxene, and precipitation of kaolinite, SiO 2 and Fe (OH) 3. Changes between local and intermediate flow components suggest dissolution of andesite rocks and precipitation of pyrite. Changes between local flow component and the cold regional component are explained by large flow trajectories. Transformations between local and hot regional components indicate mixing flows and a deep circulation influenced by the geothermal gradient. The combination of the methods used in this study can be applied in other similar geoenvironments of the world and assist local water authorities to adequately address and manage groundwater. • Geochemical models explain water-rock interaction in the flow components. • Silicate weathering and mixing flows are main water-rock processes. • Mixing quantification between thermal and non-thermal components was obtained. • A systematic geochemical modeling approach was used in a complex flow system. [ABSTRACT FROM AUTHOR]

The Mexico City region, like many other densely populated regions in the world, has problems in guaranteeing the supply of drinking water to its inhabitants. Its groundwater flow system is subject to intensive exploitation. To ensure proper water management, it is important to understand the behavior of groundwater flow system components under conditions of intensive exploitation. In this study, we analyzed 169 samples from drinking water supply wells, according to their chemistry. The principal components of the flow system were inferred using exploratory statistical analysis and analysis of the mixture of the end-members of the hydrochemical dataset. Four components were identified: (1) waters of recent infiltration and local circulation, (2) waters with evidence of intermediate chemical evolution, (3) waters that are chemically more evolved and of large flow trajectories, (4) waters that are chemically more evolved and of deep circulation. A relationship between the components, the structural geology, and the recharge zones was established. The mixing proportion of the four components in each water sample extracted from drinking water wells was identified. It was observed that the faults and the design of screened section of the well tubes influenced the mixtures captured by the wells. The impact generated by the intensive exploitation with respect to the distribution of the components within the flow system was evaluated. • The groundwater flow system was modified during the past decades. • Four flow components were identified: one local, one intermediate and two regional. • Silicate weathering and ion exchange are the most relevant water-rock interactions. • Wells have mixtures of two or more flow components related to construction design. [ABSTRACT FROM AUTHOR]

[Display omitted] • Global EDIs to PAEs and BPA reach up to 3 700 µg kg−1day−1 and 6.56 µg kg−1day−1. • HQ values to PAEs and BPA reach up to 3.66 and 9.72 × 10−2. • Studies display high CR values to BBP and DEHP, with DEHP notably surpassing BBP. • Mounting evidence shows that low-dose PAEs and BPA exposure harms human health. • Most regulatory guidelines and public policies for PAEs and BPA lack updates. Phthalates and bisphenol A (BPA) are compounds widely used as raw materials in the production of plastics, making them ubiquitous in our daily lives. This results in widespread human exposure and human health hazards. Although efforts have been conducted to evaluate the risk of these compounds in diverse regions around the world, data scattering may mask important trends that could be useful for updating current guidelines and regulations. This study offers a comprehensive global assessment of human exposure levels to these chemicals, considering dietary and nondietary ingestion, and evaluates the associated risk. Overall, the exposure daily intake (EDI) values of phthalates and BPA reported worldwide ranged from 1.11 × 10−7 to 3 700 µg kg bw−1 d−1 and from 3.00 × 10−5 to 6.56 µg kg bw−1 d−1, respectively. Nevertheless, the dose-additive effect of phthalates has been shown to increase the EDI up to 5 100 µg kg bw−1 d−1, representing a high risk in terms of noncarcinogenic (HQ) and carcinogenic (CR) effects. The worldwide HQ values of phthalates and BPA ranged from 2.25 × 10−7 to 3.66 and from 2.74 × 10−7 to 9.72 × 10−2, respectively. Meanwhile, a significant number of studies exhibit high CR values for benzyl butyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP). Moreover, DEHP has shown the highest maximum mean CR values for humans in numerous studies, up to 179-fold higher than BBP. Despite mounting evidence of the harmful effects of these chemicals at low-dose exposure on animals and humans, most regulations have not been updated. Thus, this article emphasizes the need for updating guidelines and public policies considering compelling evidence for the adverse effects of low-dose exposure, and it cautions against the use of alternative plasticizers as substitutes for phthalates and BPA because of the significant gaps in their safety. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sawdust and plastic waste are used to prepare biochars for CFX and SMX removal. • Sawdust biochar (SB) showed higher antibiotics removal compared to the hybrid one. • SB reported >95% and >99% removal efficiency for CFX and SMX, respectively. • Adsorption processes followed the PSO (R2=>0.8) kinetic model. • Adsorption occurred via H-bonding, electrostatic and π–π EDA interactions. We produced carbon-negative biochar from the pyrolysis of sawdust biomass alone (SB) and from the co-pyrolysis of sawdust and plastic waste (SPB). The co-pyrolysis approach in this study was driven by several hypothetical factors, such as increased porosity, surface chemistry, stability, as well as waste management. We applied pyrolyzed and co-pyrolyzed biochars for the removal of ciprofloxacin (CFX) and sulfamethoxazole (SMX). Due to its more alkaline and amorphous nature, SB showed better removal efficiencies compared to SPB. The maximum removals of CFX and SMX with SB were observed as ∼95% and >95%, respectively whereas with SPB were 58.8%, and 34.9%, respectively. The primary mechanisms involved in the adsorption process were H-bonding, electrostatic and π–π electron donor–acceptor interactions. Homogenously and heterogeneously driven adsorption of both antibiotics followed the pseudo-second-order kinetic model, implying electron sharing/transfer (chemisorption) mediated adsorption. The work is highly pertinent in the context of emerging concerns related to drivers that promote antimicrobial resistance. [ABSTRACT FROM AUTHOR]

A Surface Plasmon Resonance (SPR) biosensor based on an inhibition immunoassay was developed for the detection of diclofenac (DCF) in aqueous solution. Due to the small size of DCF, an hapten-protein conjugate was produced by coupling DCF to bovine serum albumin (BSA). DCF-BSA conjugate formation was confirmed via MALDI-TOF mass spectrometry. The resulting conjugate was immobilized onto the surface of a sensor fabricated via e-beam deposition of a 2 nm chromium adhesion layer followed by a 50 nm gold layer onto precleaned BK7 glass slides. Immobilization onto the nano thin gold surface was accomplished by covalent amide linkage through a self-assembled monolayer. Samples were composed of a mixture of antibody at a fixed concentration and DCF at different known concentrations in deionized water, causing the inhibition of anti -DCF on the sensor. The DCF-BSA was obtained with a ratio of 3 DCF molecules per BSA. A calibration curve was performed using concentrations between 2 and 32 μg L−1. The curve was fitted using the Boltzmann equation, reaching a limit of detection (LOD) of 3.15 μg L−1 and limit of quantification (LOQ) of 10.52 μg L−1, the inter-day precision was calculated and an RSD value of 1.96% was obtained; and analysis time of 10 min. The developed biosensor is a preliminary approach to the detection of DCF in environmental water samples, and the first SPR biosensor developed for DCF detection using a hapten-protein conjugate. [Display omitted] • An SPR immunosensor was developed to detect diclofenac in water samples. • The configuration of the immunosensor involves the conjugation of diclofenac and BSA as a carrier protein. • This is the first SPR immunosensor for diclofenac that uses the target analyte conjugated to a protein. • The obtained results are comparable with the only other work published for diclofenac detection using SPR. • The development of this kind of biosensors could help to star regulating the discharge of diclofenac in water. [ABSTRACT FROM AUTHOR]

The Mezquital Valley system is the world's oldest and largest example with regard to use of untreated wastewater for agricultural irrigation. Because of the artificial high recharge associated with the Mezquital Valley aquifers, groundwater is extracted for human consumption, and there are plans to use this groundwater as a water resource for Mexico City. Thus, this study analyzed 218 organic micro-contaminants in wastewater, springs, and groundwater from Mezquital Valley. Five volatile organic compounds (VOCs) and nine semi-volatile organic compounds (SVOCs) were detected in the wastewater used for irrigation. Only two SVOCs [bis-2-(ethylhexyl) phthalate and dibutyl phthalate] were detected in all the wastewater canals and groundwater sources, whereas no VOCs were detected in groundwater and springs. Of the 118 pharmaceutically active compounds (PhACs) and 7 reproductive hormones measured, 65 PhACs and 3 hormones were detected in the wastewater. Of these, metformin, caffeine, and acetaminophen account for almost sixty percent of the total PhACs in wastewater. Nevertheless, 23 PhACs were detected in groundwater sources, where the majority of these compounds have low detection frequencies. The PhACs sulfamethoxazole, N,N-diethyl-meta-toluamide, carbamazepine, and benzoylecgonine (primary cocaine metabolite) were frequently detected in groundwater, suggesting that although the soils act as a filter adsorbing and degrading the majority of the organic pollutant content in wastewater, these PhACs still reach the aquifer. Therefore, the presence of these PhACs, together with the high levels of the endocrine disruptor bis-2-(ethylhexyl) phthalate, indicate that water sources derived from the recharge of the studied aquifers may pose a risk to consumer health. [ABSTRACT FROM AUTHOR]

[Display omitted] • TGA at three heating rates is performed to access the kinetics of treated sunnhemp. • KAS, FWO, Friedman and Starink methods used to find activation energy of pyrolysis. • Pre exponential factor (A) is calculated using DAEM method. • Linear relationship between E a and ln A is established with R2 = 0.95. • Standard deviation calculated to validate the activation energy values. Sun hemp fibers are natural fibers obtained from plants grown in India and nearby countries. It is lignocellulosic biomass having the complex structure of hemicelluloses, cellulose and lignin. Chemical treatment of natural fibers is in practice to enhance the properties being used as reinforcement. Alkaline-treated fiber was sampled and thermal stability along with kinetic parameters was assessed with thermo gravimetric data at heating rates 10, 20 and 30 °C/min using four model-free methods Kissinger–Akahira–Sunose (KAS), Flynn-Wall-Ozawa (FWO), Friedman (FM), Starink (STAR) along with Distributed activation energy model (DAEM) to calculate pre-exponential factor. The calculated activation energy E a by these model-free methods were in the range of 93.3–104.8 kJ/mol and pre-exponential factor (A) was observed between the range 46.6 x103–90.5 x106/min by the DAEM method. The standard deviation (σ) calculated from average activation energy using all four methods was 4.5 kJ/mol, which showed the consistency in the methods employed to determine the activation energy of sun hemp. [ABSTRACT FROM AUTHOR]

[Display omitted] • A framework for water-energy-carbon nexus for water distribution networks. • Application of design of experiment methods micro hydro power optimization. • Creating an energy harvesting soft-sensor by artificial neural network. • Implementation of an operational control system by Petri Net model. Today energy recovery using Micro-Hydropowers (MHPs) in Water Distribution Networks (WDN) is a well-known approach for recycling the wasted energy in infrastructures as a sample of circular economy. Likewise, in this study for the first time a framework for evaluation of WDN for energy harvesting have been designed with the application of statistical optimization, simulation, and artificial intelligence concepts. In this study, after modelling a WDN in Mashhad, Iran, with Environmental Protection Agency Network Evaluation Tool (EPANET) software, the potential of energy recovery using MHP technology was optimized with the application of Design of Experiment (DOE) methods, including Taguchi and Response Surface Methodology (RSM) and then the model prediction ability was improved by Artificial Neural Network (ANN) technique. Results of this investigation revealed that the combination of Taguchi and RSM methods could successfully optimize the energy recovery potential with consideration of improving the hydraulic parameters of WDN. With the application of RSM and Taguchi, high potential positions for MHP placement are detected and analyzed based on a high-performance operational decision-making methodology. According to Artificial Intelligence (AI) computations, energy harvesting and hydraulic responses can be estimated with more than a 99 % correlation coefficient. Also, it shows that the soft-operator can be executed to control the features of MHPs in WDNs. The outputs of this research demonstrated that MHP harvested energy is more than 400KW for the run time of this study with consideration of hydraulic parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sources, fate and occurrence of phthalates and BPA in aquifers have been reviewed. • Phthalates and BPA have been globally detected in groundwater reservoirs. • Landfills, sewage sludge and wastewater are the main sources to groundwater pollution. • Some phthalate and BPA features and soil conditions promote the transport to aquifers. • Worldwide guidelines values for drinking water vary in a wide range of concentrations. Phthalic acid esters (PAEs) or phthalates and bisphenol A (BPA) are emerging organic contaminants (EOCs) that may harm biota and human health. Humans can be exposed to these contaminants by drinking water consumption from water sources such as groundwater. Before their presence in aquifer systems, phthalates and BPA can be found in many matrices due to anthropogenic activities, which result in long-term transport to groundwater reservoirs by different mechanisms and reaction processes. The worldwide occurrence of phthalates and BPA concentrations in groundwater have ranged from 0.1 × 10−3 to 3 203.33 µg L−1 and from 0.09 × 10−3 to 228.04 µg L−1, respectively. Therefore, the aim of this review is to describe the groundwater contamination pathways of phthalates and BPA from the main environmental sources to groundwater. Overall, this article provides an overview that integrates phthalate and BPA environmental cycling, from their origin to human reception via groundwater consumption. Additionally, in this review, the readers can use the information provided as a principal basis for existing policy ratification and for governments to develop legislation that may incorporate these endocrine disrupting compounds (EDCs) as priority contaminants. Indeed, this may trigger the enactment of regulatory guidelines and public policies that help to reduce the exposure of these EDCs in humans by drinking water consumption. [ABSTRACT FROM AUTHOR]