Environmental Monitoring and Assessment最新文献

Microplastics (MPs) have become a major global environmental problem due to their accelerated distribution throughout different environments. Their widespread presence is a potential threat to the ecosystems because they alter the natural interaction among their constituent elements. MPs are considered as emergent pollutants due to the huge amount existing in the environment and by the toxic effects they can cause in living beings. The removal of MPs from water bodies and wastewaters is a control strategy that needs to be implemented from the present on and strictly constantly in the near future to control and mitigate their distribution into other environments. The present work shows a detailed comparison of the current potential technologies for the remediation of the MPs pollution. That is, physical, biological, and chemical methods for the removal of MPs from water bodies and wastewaters. Focusing mainly on the discussion of the perspective on the current innovative technologies for the removal or degradation of the MPs, rather than in a deep technical discussion of the methodologies. The selected novel physical methods discussed are adsorption, ultrafiltration, dynamic membranes and flotation. The physical methods are used to modify the physical properties of the MPs particles to facilitate their removal. The biological methods for the removal of MPs are based on the use of different bacterial strains, worms, mollusks or fungus to degrade MPs particles due to the hydrocarbon chain decrease of the particles, because these kinds of microorganisms feed on these organic chains. The degradation of MPs in water bodies and wastewaters by chemical methods is focusing on coagulation, electrocoagulation, photocatalysis, and ozonation. Chemical methods achieve the degradation of MPs by the modification of the chemical structure of the particles either by the change of the surface of the particles or by attacking radicals with a high oxidation capacity. Additionally, some interesting combinations of physical, chemical, and biological methods are discussed. Finally, this work includes a critical discussion and comparison of several novel methods for the removal or degradation of MPs from water bodies and wastewaters, emphasizing the areas of opportunity and challenges to be faced.

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This study investigates the spatial and temporal distribution of 21 pesticides across soil and water in three major agricultural tehsils (Nawabshah, Sakrand, and Daur) of district Shaheed Benazirabad, Pakistan, spanning spring, summer, and autumn 2023. Method sensitivity and precision allowed for detection limits (LOD) ranging from 0.016–0.056 in water and 1.39–4.64 in soil with a limit of quantification (LOQ) ensuring high accuracy. Results showed peak pesticide concentrations during summer with detection rates of 74.15% in soil, and 61.2% in water followed by autumn (55.78% and 36%) and spring (30.91% and 24.4%) in soil and water respectively. Highest detection frequencies of chlorpyrifos (882 µg/kg), profenofos (663 µg/kg), malathion (645 µg/kg), and endosulfan (973 µg/kg) were found in soil. Significant concentrations of dimethoate (0.657 µg/L), DDT (0.675 µg/L), and bifenthrin (0.458 µg/L) were recorded in water samples. Sakrand soil exhibited the highest contamination during the summer season reaching the level of 5070 μg/kg soil, highlighting the impact of intensive agriculture practices. Significant correlations were found between pesticide retention and soil and water physiochemical properties. The highest positive correlation was found in pesticide retention with OM and soil pH with CaCO₃ and sulfate and nitrate in water. This study establishes a baseline for pesticide contamination in this agricultural region and analyzes the factors in soil and water that affect pesticide mobility. These findings suggested that environmental monitoring and strict pesticide regulation during peak agriculture season could minimize ecosystem contamination, protect human health, and encourage regulatory and conservation initiatives in high-intensity farming areas.

In this study, spatial and temporal characteristics of meteorological droughts in the Marmara Basin, which is located in the semi-arid climate region with the highest population density in Turkey, were determined using HadGEM2-ES global climate model data. Here, precipitation projection data using both RCP 4.5 and RCP 8.5 scenarios were employed. The Standardized Precipitation Index (SPI) was employed to calculate drought intensities, and areal distributions of drought were determined using the inverse distance weighting (IDW) interpolation method. Drought intensity-area-frequency (DIAF) curves for the basin were created by converting point drought intensity data into areal drought data. The DIAF curves provided analysis of the temporal and spatial characteristics of droughts in the basin and revealed that drought intensities are projected to be higher under the RCP 8.5 scenario.

Sodium iodide (NaI(Tl)) scintillation detector is commonly used for gamma-ray spectrometric evaluations in airborne surveys and geophysical well logging. However, the applications related to environment monitoring are often encountered with challenges of low-level counting (LLC), demanding a high-resolution spectrometry system, such as a high purity germanium (HPGe) system. HPGe systems are expensive and cannot be used continuously due to the necessary supply of liquid nitrogen. In this paper, the possibility to use relatively poor resolution NaI(Tl) detector for measuring low-level radioactivity due to principal nuclides by spectrum unfolding has been explored. We quantified the activities of principal radionuclides, ²³²Th, ²³⁸U, and ⁴⁰ K, in soil samples from NaI(Tl) spectral measurements by spectrum decomposition (SD) and matrix deconvolution (MD) techniques. The specific activities of radionuclides were statistically characterized with respect to the measurements made with HPGe detector. The comparison suggests that activities determined with NaI(Tl) detector were underestimated in the majority of cases. However, the activity of ²³⁸U measured with the MD method was overestimated. The results of SD were closer to the HPGe detector measurements as compared to the MD method. Considering the normal distribution of measurements from both detectors, correlation coefficients were computed that led to the development of linear regression models to numerically transform NaI(Tl) measurements to HPGe equivalent activities within statistically acceptable bounds. Thus, a low-resolution but high-efficiency NaI(Tl) detector provides a cost-effective and time-saving alternative to HPGe measurements for the routine environmental radioactivity surveys, since it offers continuous operation and provision for carrying in fields as well, which facilitates sample characterization and thereby quick assessment of radiological hazards.

The present study is among the first to assess the health and environmental risks of heavy metals (HMs) in the soil of palm farms in the Al-Jilah area, west of Riyadh. This was achieved by analyzing HM concentrations in surface soil samples using Inductively Coupled Plasma Mass Spectrometry. The findings revealed that metal concentrations followed a descending order: (µg/g): Fe (14,528) > Mn (163.47) > Sr (156.72) > Zn (30.11) > Cr (28.61) > Ni (20.58) > Cu (11.44) > Co (6.44) > Pb (5.28). The highest concentrations of Cu (42 µg/g), Pb (12 µg/g), and Sr (621 µg/g) were recorded in farm-21, located in the central region of the study area, which is characterized by intensive agricultural activity. Both the geo-accumulation index (Igeo) and the modified contamination degree (mCdeg) indicated no contamination, with Igeo values ranging from -3.00 to -1.86 and mCdeg value of 0.32. These results were further supported by the toxicity risk index, which showed very low toxic risks (0.18–1.38). Health risk assessments, represented by chronic daily intake and hazard index values, were conducted to evaluate potential non-carcinogenic risks. The results indicated that iron had the highest daily intake exposure, particularly in children. However, all HI values remained below 1, confirming health risks from soil exposure. Similarly, the cancer risk and lifetime cancer risk values were below the threshold of concern, indicating that the soil does not pose a carcinogenic threat. These findings suggest that the soil of palm farms in the Al-Jilah area is safe, with no evidence of non-carcinogenic or carcinogenic risks. However, continuous environmental monitoring remains crucial to preserving soil quality, given its significance for food security.

An innovative mixed matrix membrane (MMM) has been built by interfacial polymerizing of polyethersulfone membrane by modification with silica/carbon dots and a silica/carbon dots/ZrO₂ hybrid nanoarchitecture based on glucose sugar and trimesoyl chloride on an alkali solution. The silica-based hybrid nanoarchitectures have been obtained by a combination of carbon dots nanomaterials, zirconium oxide (ZrO₂), and silica (SiO₂) employing the sol–gel method using fluoride ions (F⁻) as catalysts. These MMM hybrid nanoarchitectures were characterized by scanning electron (SEM), high-resolution transmission electronic (HR-TEM) microscopies, X-ray diffraction (XRD), and infrared and ultraviolet–visible spectroscopy techniques. The produced nanofilters have retained different dangerous analytes, such as dyes (methylene blue and methyl orange) and endocrine disruptors (bisphenol A) found in potable water. The retention rate was measured by UV–vis spectroscopy, which showed retention capacity for methylene blue at 94% and bisphenol A at 80% in real samples. In the deionized water, the bare PES support presented a flow rate of 41.7 L.h⁻¹, SiO₂/HF/Cdot/PES of 36.9, and SiO₂/HF/Cdot/ZrO₂/PES of 40.7 L.h⁻¹. Therefore, these nanofilters have a high potential to retain dyes and endocrine disruptors, effectively avoiding environmental contamination.

Heavy metal speciation is an important tool for the assessment of sediment quality. This work was conducted to investigate the geochemical occurrence, distribution, and spatial variability of sediment heavy metals in the Hirakud Reservoir (a Ramsar site) of the Mahanadi River in India. Estimation based on a single-extraction (speciation) method revealed the dominance of Fe–Mn-bound (39.33%) fractions suggesting the potential mobility of heavy metals. Co-dominance of residual (35.03%) and organic matter–sulfide (23.02%) fractions indicate lattice-bound associations of elements under natural conditions and suggest anthropogenic organic input contribution respectively. The heavy metals distribution was spatially affected (p < 0.05). While, Ag, Cd, Hg, and Mo displayed extremely severe enrichment (EF > 50) and very strong geo-accumulation conditions (I_geo > 5); Cd and Hg displayed very high ecological risk (ERF > 320). However, the contamination factor for all heavy metals except Cd and Hg showcased low contamination (CF < 1). The principal component and cluster analysis revealed that the source of Mn, Mo, Hg, and Ag was mainly from anthropogenic or biogenic origin. The Fe and Al however displayed signs of being derived from multiple sources. However, the risk assessment code (RAC) results suggest that As exhibited a medium to very high risk (11 < RAC < 30) of bio-availability. Thus, the results of this study can be used for the formulation of strategies for the reduction of anthropogenic loads, planning for sediment quality management, and regular monitoring to curb the rising pollution issues of the reservoir.

Basins play a crucial role in regional ecosystems and the supply of water resources. However, owing to regional constraints and insufficient research resources, the ecological health of small basins in county-level areas has not been adequately studied. To explore a simple and practical method for assessing the ecological health of small county-level basins, this study uses the Fan River Basin as a case study to construct a dual spatial scale evaluation framework that encompasses both aquatic and terrestrial ecosystems. The evaluation indicators for the aquatic ecosystem include the Water Quality Condition Index, River Connectivity Index, and Macrobenthic Diversity Composite Index, alongside eight additional indicators. The evaluation of the terrestrial ecosystem incorporates nine core indicators, such as the Forest Coverage Index, Water Source Containment Function Index, and Important Habitat Conservation Index. The entropy weighting method was employed to determine the weights of the indicators, followed by quantitative analysis. The results indicate that the aquatic ecosystem of the Fan River Basin generally falls into the “Moderate” level; however, water quality and species diversity are facing a certain degree of pressure. In the terrestrial ecosystem, forest coverage and soil conservation functions performed well, while habitat conservation and water source containment functions were relatively weak and significantly affected by human activities. Based on the evaluation results, optimization strategies for basin management and sustainable development have been proposed, providing valuable references for decision-makers to promote ecological civilization and sustainable development.

Graphical Abstract

Heavy metals are among the important environmental pollutants, yet their impact in remote areas remains underexplored because of limited studies on their monitoring. This study presents the first dendrochemical analysis from Mizoram, using Magnolia champaca tree rings to assess heavy metal concentration trends at a natural forest site (Site-I) and a roadside plantation (Site-II) for about two and half decades (from 1993 to 2019). The concentrations of Zn, Pb, Fe, Cu, Ni, and Mn were analyzed in tree rings to reconstruct pollution history. The results revealed a significant difference between the two sites, with roadside tree cores exhibiting greater variability and steadily increasing heavy metal concentrations as compared to natural forest. The mean concentrations of metals in natural forest samples were in the order: Fe (18.22 mg kg⁻¹) > Mn (12.01 mg kg⁻¹) > Ni (7.23 mg kg⁻¹) > Cu (3.71 mg kg⁻¹) > Pb (0.398 mg kg⁻¹) > Zn (0.411 mg kg⁻¹). In contrast, roadside samples showed considerably higher metal concentrations in the order: Mn (39.92 mg kg⁻¹) > Fe (22.9 mg kg⁻¹) > Ni (11.61 mg kg⁻¹) > Cu (10.28 mg kg⁻¹) > Zn (6.723 mg kg⁻¹) > Pb (3.17 mg kg⁻¹). Notably, M. champaca samples collected from the roadside contained elevated levels of Pb, Fe, Cu, and Ni, exceeding the permissible limits for plant parts as prescribed by the WHO. The study underscores the potential of species as a bioindicator of heavy metal pollution. These findings are crucial for informing soil management, pollution control, and understanding nutrient-metal cycling in trees. Further research is needed to explore the plant-soil interactions and behaviours of heavy metals in these environments.

Wastewater has been identified as one of the main contributors to microplastic (MP) pollution in aquatic environments. Hence, this study investigates the presence, characteristics of MPs in wastewater sample types (industrial, domestic, and medical wastewater), and also the removal efficacy of MPs by local wastewater treatment stations. Overall, industrial wastewater showed a higher MP abundance level at 60,881 ± 48,154 items/m³, compared to domestic and medical wastewater with values of 31,494 ± 10,142 items/m³ and 35,453 ± 13,186 items/m³, respectively. Fiber and fragment were the main shapes observed among the MPs found in all wastewater samples, and the dominant form was microfiber, ranging from 63 to 97.5% of total MPs. The performance of local wastewater treatment stations showed varied efficiencies in MP removal, ranging between 15.8 ± 5 and 90.2 ± 1.3%. Domestic wastewater treatment stations showed lower MP removal effectiveness, at 43.9 ± 13.1%, while treatment stations receiving industrial and medical wastewater achieved 59.5 ± 20.7 and 69.6 ± 22.1% of removal efficiencies, respectively. As estimated, 2.9 × 10¹⁰ microplastic items could be emitted to the water bodies around Hanoi every day, which MPs originated from domestic wastewater accounted for 80.3% due to its high discharge volume and inadequate treatment capacity. Optimization of the septic tank system operation and the sewage sludge treatment processes could prevent secondary contamination of MPs, while an additional primary sedimentation step could improve the overall MP elimination efficacy of the studied treatment stations. The results from this study suggested that more in-depth investigations were required for a proper understanding of the migration routes of MPs from different anthropogenic activities to wastewater.