The purpose of this work is to address an environmental problem in Mexico, which uses significant amounts of water for agricultural activities, where atrazine is frequently used as a pesticide for weed control. Currently, there is no law prohibiting its use, even though it is considered an endocrine disruptor in some mammals and harmful to health. Due to the difficulty in the direct quantification of several herbicides, which present a low concentration in water, the present work aims to develop the optimization and validation of the preconcentration with magnetic stir bars (SBSE) in aqueous samples for the quantification of atrazine and two of its metabolites: 2-hydroxyatrazine (2-HA) and desethylatrazine (DEA), coupled to High-Performance Liquid Chromatography (HPLC-UV/DAD). For the optimization of the preconcentration technique, the nature and quantity of the solvents used in each step, contact time for retention and quantitative extraction of the analyte, as well as the effect of the concentration of the analyte on its retention on the bar were considered. Finally, it was determined that the presence of the metabolites 2-HA and DEA does not affect the sorption of atrazine on the sorption bar used. The analytical methodology can be considered as an efficient method of atrazine preconcentration for subsequent quantification via HPLC-UV/DAD in the range of 0.03 to 0.25 mg/L and in the absence of matrix interferences; its limits of detection and quantification are respectively 0.0014 mg/L and 0.0016 mg/L.

The environmental impacts of mining, quarrying, and the stone processing industry are significant, affecting air quality, health, and the socioeconomic status of communities worldwide. Key contributors to air pollution include the waste of raw materials from quarrying, non-compliance with scientific protocols, and the extraction of natural mineral resources. The rapid increase in pollution sources, such as dust, water, and noise, has led to the release of various pollutants into the atmosphere, degrading local air quality. This study conducted sampling at twelve sites, adhering to the Central Pollution Control Board’s (CPCB) monitoring guidelines. Twelve metrics, including PM10, PM2.5, SO2, NOx, CO, O3, Pb, NH3, C6H6, C2OH12, As, and Ni, were measured twice a week over a three-month period (January 2024 to March 2024) by the National Ambient Air Quality Standards (NAAQS) in the research area. The results indicated that while SO2 and NOx levels were within permissible limits at all monitored locations, Suspended Particulate Matter (SPM) levels were high at every station. The average baseline levels of PM10 (37.17 μg/m³ to 70.52 μg/m³), PM2.5 (16.98 μg/m³ to 39.85 μg/m³), SO2 (5.29 μg/m³ to 13.91 μg/m³), NOx (9.8 μg/m³ to 29.71 μg/m³), CO (0.15 mg/m³ to 0.32 mg/m³), O3 (6.9 μg/m³ to 15.37 μg/m³), and NH3, Pb, Ni, As, C2OH12, and C6H6 were below the detection levels (BDL) and limits of quantification (LOQ), all within the National Ambient Air Quality Standards for commercial, industrial, and residential areas during the study period. This research highlights the urgent need for effective pollution control measures to mitigate the adverse environmental and health impacts of these industries.

This research explores the effectiveness of ZnO and Ag-doped ZnO photocatalysts in degrading organic pollutants, specifically focusing on phenol removal in wastewater treatment. The catalysts were synthesized using sol-gel and precipitation methods and characterized through XRD, SEM, and EDX analyses. The study assessed the degradation efficiency of phenol under various conditions, including different catalyst dosages, irradiation times, and initial phenol concentrations. UV-vis spectroscopy was used to measure degradation efficiency, revealing significant differences between the two catalysts. Ag-doped ZnO showed superior performance, achieving degradation efficiencies of over 90%, compared to ZnO’s 60-70%. Statistical analyses, including ANOVA and Response Surface Methodology (RSM), identified key factors influencing degradation efficiency. The enhanced performance of Ag-doped ZnO was attributed to its narrower band gap energy and improved irradiation responsiveness. These findings indicate that Ag-doped ZnO is a promising candidate for efficient and sustainable wastewater treatment, offering a robust solution for removing organic impurities and supporting environmental preservation. This research provides valuable insights into advanced photocatalytic processes and sets the stage for future wastewater treatment innovations.

The discharge of large quantities of organic dyes into the environment causes significant harm to humans and the environment. Thus, there is an urgent need to develop cost-effective adsorbents for removing these dyes. In the present study, the synthesis of activated carbon (AC) derived from mixed fish scale waste using KOH activation was investigated for Congo red (CR) dye removal. The finding shows that the obtained biocarbon has a fixed carbon of 42.9% with a crystallinity index of 15.01%. N2 adsorption-desorption isotherm was found to be type IV, signifying mesoporous structure with a surface area and total pore volume of 150.049 m2 g-1 and 0.119 cm3.g-1. Batch adsorption was carried out by various adsorbent doses, initial concentration, contact time, and pH to comprehend the effect of operating parameters on its removal efficacy. The isotherm studies fitted well for Freundlich with an R2 of 0.99%. Adsorption kinetics was best fitted by the pseudo-second-order model and thermodynamic studies revealed the adsorption process to be exothermic and spontaneous. The efficiency of AC was also studied by an amount of sorption and desorption cycles which showed its potential for reusability up to the sixth cycle. Thus, the findings suggest that activated carbon derived from mixed fish scale waste is a promising adsorbent for removing Congo red dye from aqueous solutions.

This study investigated the efficacy of oxidised iron-loaded activated carbon cloth (Fe-ACC) for selective recovery of phosphorous. The capacitive deionisation (CDI) technology was employed, for rapid removal of phosphate, with the aim of reducing the reliance on high alkalinity environment for the regeneration of Fe-ACC electrode. Multiple experimental parameters, including applied potential, pH, and co-existing ions, were studied. Additionally, the CDI system was tested on a real water matrix (Lake Ormstrup, Denmark) to elucidate the electrodes’ performance on selective recovery of phosphate. About 69 ± 10% of the adsorbed phosphate were released at pH 12 via pure chemical desorption, which was ~ 50% higher than that at pH 9. The CDI system successfully demonstrated the selective removal of phosphate from the lake water. It reduced the concentration of phosphate from 1.69 to 0.49 mg/L with a 71% removal efficiency, while the removal percentages of other anions, namely chloride, sulphate, bromide, nitrite, nitrate, and fluoride, were 10%, 7%, 1%, 1.5%, 4%, and 7%, respectively.

There is growing evidence of negative impacts of antidepressants on behavior of aquatic non-target organisms. Accurate environmental risk assessment requires an understanding of whether antidepressants with similar modes of action have consistent negative impacts. Here, we tested the effect of acute exposure to two antidepressants, fluoxetine and venlafaxine (0–50 µg/L), on the behavior of non-target organism, i.e., freshwater pond snail, Lymnaea stagnalis. As compounds interact with chemical cues in the aquatic ecosystems, we also tested whether the effects altered in the presence of bile extract containing 5α-cyprinol sulfate (5α-CPS), a characterized kairomone of a natural predator, common carp (Cyprinus carpio). Behavior was studied using automated tracking and analysis of various locomotion parameters of L. stagnalis. Our results suggest that there are differences in the effects on locomotion upon exposure to venlafaxine and fluoxetine. We found strong evidence for a non-monotonic dose response on venlafaxine exposure, whereas fluoxetine only showed weak evidence of altered locomotion for a specific concentration. Combined exposure to compounds and 5α-CPS reduced the intensity of effects observed in the absence of 5α-CPS, possibly due to reduced bioavailability of the compounds. The results highlight the need for acknowledging different mechanisms of action among antidepressants while investigating their environmental risks. In addition, our results underline the importance of reporting non-significant effects and acknowledging individual variation in behavior for environmental risk assessment.

The factors limiting micropollutant biodegradation in the environment and how to stimulate this process have often been investigated. However, little information is available on the capacity of microbial communities to retain micropollutant biodegradation capacity in the absence of micropollutants or to reactivate micropollutant biodegradation in systems with fluctuating micropollutant concentrations. This study investigated how a period of 2 months without the addition of micropollutants and other organic carbon affected micropollutant biodegradation by a micropollutant-degrading microbial community. Stimulation of micropollutant biodegradation was performed by adding different types of dissolved organic carbon (DOC)—extracted from natural sources and acetate—increasing 10 × the micropollutant concentration, and inoculating with activated sludge. The results show that the capacity to biodegrade 3 micropollutants was permanently lost. However, the biodegradation activity of 2,4-D, antipyrine, chloridazon, and its metabolites restarted when these micropollutants were re-added to the community. Threshold concentrations similar to those obtained before the period of no substrate addition were achieved, but biodegradation rates were lower for some compounds. Through the addition of high acetate concentrations (108 mg-C/L), gabapentin biodegradation activity was regained, but 2,4-D biodegradation capacity was lost. An increase of bentazon concentration from 50 to 500 µg/L was necessary for biodegradation to be reactivated. These results provide initial insights into the longevity of micropollutant biodegradation capacity in the absence of the substance and strategies for reactivating micropollutant biodegrading communities. Graphical abstract: (Figure presented.)

Global warming and its consequences have heightened the urgency of reducing emissions of carbon dioxide globally. The concern arises from countries’ relentless efforts to achieve economic development at the expense of the environment. In this context, the paper examines the Environmental Kuznets Curve (EKC) hypothesis at the world level using carbon emission as an indicator of environmental degradation. The EKC hypothesis postulates an inverted U-shaped curve between economic development and environmental degradation; degrading environmental quality at the initial stages of development and, after a threshold level, environmental degradation lowers. The study investigates the validity of the EKC hypothesis for carbon emission with an analysis of 158 countries in the world, with population, urbanization, forest cover, and tourist inflow as the control variables. The study is based on secondary data collected from the World Bank. A regression analysis is used for the study. To ensure environmental sustainability, it is important to identify the determinants of carbon emissions across countries with varying levels of economic development. The findings of the study support the hypothesized inverse U-shaped association between Gross Domestic Product per capita and carbon emission per capita at the world level. Out of the four control variables, urbanization and tourist inflow were found statistically significant. Urbanization was positively correlated with carbon emission per capita while forest area was negatively correlated. Carbon emission per capita initially increases with rising GDP per capita and declines after GDP per capita reaches a certain level. The estimated turning point of GDP per capita occurs at a high level and therefore, most of the countries are anticipated to emit carbon dioxide.

Precipitation is a fundamental variable that is widely used in the organization of water resources and has a great influence on hydrological processes and ecological assessment. This study investigated the quantitative effect of monthly precipitation on surface water area (denoted by the Modified Normalized Difference Water Index, MNDWI), vegetation area (denoted by Normalized Difference Vegetation Index, NDVI), and potential evapotranspiration (PET) during two years (2018 and 2021) in the city of Baghdad, Iraq. Using the Thornthwaite aridity index, the annual aridity was first assessed to quantify the climate category of these years. The result shows that they were semi-arid and very arid, respectively. The empirical relationships between precipitation and areas of MNDWI and NDVI, and between rainfall and PET, were also examined. Due to less precipitation in 2021, no relationship was found in arid climates, while in 2018 for semi-arid climates, precipitation had a positive non-linear correlation with MNDWI and NDVI areas and a negative correlation with PET.

This study marks the first report on the genetic characterization of Penicillium expansum strain capable of mycotoxin production isolated from river water. Situated in Ganagalawanipeta village, Srikakulam, Andhra Pradesh, India, where river water serves as a vital resource, our investigation probed the presence of pathogenic opportunistic fungi adept at mycotoxin synthesis. Over six months, 30 samples were collected to assess their occurrence. This article revolves around the use of morphological traits for Penicillium genus identification. Precise species determination involved PCR analysis using universal primers ITS1 and ITS4, followed by sequence analysis through NCBI-BLASTn and the ITS2 database. The analysis indicated a striking 99.49% genetic similarity to Penicillium expansum isolate MW559596 from CSIR-National Institute of Oceanography, Goa, an Indian isolate, with a resultant 600-base pair fragment. This sequence was officially cataloged as OR536221 in the NCBI GenBank database. Sequence and phylogenetic assessments were conducted to pinpoint the strain and geographical origin. Notably, the ribosomal nuclear ITS region displayed significant inter- and intra-specific divergence, manifested in DNA barcodes and secondary structures established via minimum free energy calculations. These findings provide crucial insights into the genetic diversity and potential mycotoxin production of P. expansum isolates, shedding light on the environmental repercussions and health risks associated with river water contamination from agricultural and aquaculture effluents. This pioneering research advances our understanding of mycotoxin-producing fungi in aquatic environments and underscores the imperative need for water quality monitoring in regions reliant on such water sources for their sustenance and livelihoods.