This study reports the fabrication and performance evaluation of electrospun nanofiber membranes made from recycled acrylic (polymethyl methacrylate (PMMA)) for use in Scanning Electron Microscopy (SEM) confirmed that the membranes possessed a uniform, highly porous nanofibrous structure with interconnected pores conducive to vapor transport. Atomic Force Microscopy (AFM) revealed a rough surface morphology, while water contact angle measurements exceeding 121 degrees indicated excellent hydrophobicity, critical for the preservation of key ester functional groups, confirming the chemical integrity of the recycled acrylic. Performance testing was conducted under various feed temperatures (45- 65 degrees C), flow rates (0.2-0.4 L/min), NaCl concentrations (35-140 g/L), and air gap distances (6-9 mm). The membranes achieved a maximum flux of 9.2 kg/m2 & centerdot;h at 65 degrees C and 0.4 L/ min. As expected, higher salt concentrations reduced flux due to lower vapor pressure and increased concentration polarization. Despite variations in operating conditions, salt rejection consistently exceeded 99.994%, demonstrating excellent selectivity and operational stability. These results highlight the potential of recycled acrylic-based nanofiber membranes as a sustainable and high-performance solution for brine desalination using AGMD.
To improve the absorption and desorption performance of aqueous MDEA solution, a hybrid solvent composed of 40 wt.% MDEA and 20 wt.% Sulfolane was prepared and systematically evaluated under varying pressure conditions. At (0.1-0.5 MPa) pressures, the conventional aqueous MDEA solution exhibited a higher CO(2 )absorption capacity in comparison to the hybrid solution, indicating its effectiveness in less pressurized environments. However, under high-pressure (>0.5 MPa) conditions, the hybrid solution demonstrated superior performance, reaching 3.28 mol & centerdot;kg(-1 )CO(2 )molality, compared to 2.94 mol & centerdot;kg(-1 )for the conventional solution. This enhanced capacity highlights the beneficial interaction between MDEA and sulfolane at elevated pressures. Additionally, the hybrid formulation improved the regeneration efficiency by 3.7% relative to the standard MDEA solution, indicating better solvent recyclability. The incorporation of 0.1 wt.% MIL101-NH2(Cr) nanoparticles into the hybrid solvent further enhanced system performance, increasing CO2 molality by 17.1% suggesting enhanced surface area, the porous surface, the amine functional groups and active site availability for CO2 interaction. elevating the regeneration efficiency to 99.45% at an operating temperature of 80 degrees C, demonstrating the underscoring the synergistic role of nanomaterials in advancing solvent-based CO2 capture technologies.
This study investigates the spatial distribution of key air pollutants-NO2, SO2, CO, and surface O3-across three southern districts of Tamil Nadu, India: Tuticorin, Tirunelveli, and Kanniyakumari, for the period April 2024 to March 2025. Pollutant data were derived from the Copernicus Sentinel-5P satellite and analyzed using the Google Earth Engine (GEE) platform to map annual variations and identify pollution patterns. The results showed that Tuticorin experienced the highest pollutant levels due to its dense industrial and port activities, followed by Tirunelveli, where urban growth and traffic contributed to moderate concentrations. Kanniyakumari, characterized by its coastal setting and minimal industrialization, recorded the lowest levels. Satellite-derived data were further compared with ground-based measurements from TNPCB and AQI India for validation. The novelty of this work lies in its use of satellite-based atmospheric observations and cloud computing (GEE) for air quality analysis in southern Tamil Nadu, a region where such remote sensing studies remain limited.
This study evaluated the effectiveness of microbial-induced carbonate precipitation (MICP) in immobilizing heavy metals, using the most resistant bacterial strain isolated from petroleum-contaminated soil. Among the 16 strains isolated from soil near oil wells in Khuzestan, Iran, Citrobacter sp. strain PO2 was identified as the most effective in stabilizing a mixture of highly toxic heavy metals. The strain has been deposited in the NCBI database under accession number PP864728. The analysis was performed using inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) techniques. The results showed that the isolated bacterium removed 96.08% of copper, 97.47% of zinc, 99.89% of lead, 72.60% of cadmium, and 60.59% of nickel from a medium containing a mixture of heavy metals at a concentration of 800 mg/L, after 24 hours of incubation at 30 degrees C. At a concentration of 1500 mg/L, the bacterial strain removed 93.56%, 94.64%, and 97.59% of copper, zinc, and lead, respectively, from the mixed heavy metal solution, while no significant removal of cadmium and nickel was observed at this concentration. At a concentration of 1200 mg/L, bacterial removal efficiencies were 22.07% for cadmium and 6.29% for nickel, respectively. The toxicity of the heavy metals was ranked as follows: Pb > Cu = Zn > Cd > Ni. The MICP process thus represents a promising biological approach for stabilizing heavy metals, offering significant potential for applications in ecological restoration.
Microplastic pollution in water sources poses a serious threat to human health and natural ecosystems. This research examines the efficiency of the proton-induced gamma emission (PIGE) method combined with bidirectional long short-term memory (Bi-LSTM) neural networks and MCNPX numerical simulations for the accurate detection of microplastics. Utilizing MCNPX simulations, the optimal proton energy (3 to 7 MeV) and predicted gamma spectra for environmental samples were determined. Results showed that the PIGE method is most effective at energies of 3 to 7 MeV for high concentrations and at higher energies for concentrations below 1%. The Bi-LSTM model, a subset of artificial neural networks with bidirectional architecture, was configured with a learning rate of 0.001 and trained over 100 epochs (with a batch size of 32). To prevent overfitting, Dropout and Batch Normalization layers were used, while Early Stopping and (ReduceLROnPlateau) mechanisms optimized the training process by monitoring the validation loss and dynamically adjusting the learning rate. This hybrid system achieved an accuracy of 95%, sensitivity of 93%, and an F1 score of 94%, indicating significant improvement over conventional methods. This approach offers a reliable solution for tracking microplastics and, due to its applicability in complex environments like oceans and groundwater, has the potential to become a global standard such as ISO. In the future, it can be integrated with the Internet of Things (IoT) for real-time monitoring and better environmental protection.
Nayarit, is a leading aquaculture state in Mexico, so evaluating the physicochemical characteristics of the water is essential for monitoring the region's aquaculture systems. For this, the objective was to evaluate the hydrological and ecological suitability of water in shrimp production. Physical and chemical variables (dissolved oxygen, pH, temperature, turbidity, and salinity) were measured at 15 pumping water points during the winter and summer seasons. The Hydrological Aptitude Index (HAI) was calculated weighing the parameters from highest to lowest according to their importance for shrimp development. The ecological suitability was assessed following the guidelines of the Canadian Council of Ministers of the Environment (CCME) for Ecological Criteria for Water Quality compliance. The results indicated that the parameters dissolved oxygen (2.2 to 10.3 mg/L), temperature (24 to 35 degrees C) and pH (7.3 to 9.1) were identified as significant predictors of water quality according to the Mann-Whitney test (p < 0.05). Winter offered the best conditions for shrimp; the HAI classified hydrological suitability from requiring little management to having excellent quality (6 - 10) in 66.7 % of the samples. Although, a lack of correlation with shrimp productivity is shown in the Spearman test (p > 0.05). According to CCME, ecological conditions rarely or sometimes deviate from desirable levels (65-94) at 53.3% of sites. This research sets a precedent for the current state of aquaculture tributaries in Nayarit and proposes the use of quality indices as a tool for the comprehensive analysis of water suitability for Litopenaeus vannamei production.
Strategic Environmental Assessment (SEA) plays a crucial role in integrating environmental considerations into national planning and decision-making. However, its successful implementation requires a robust legal, institutional, and financial framework tailored to national conditions. This study investigates the challenges and opportunities of implementing SEA in Iran, emphasizing its potential role in pollution management and sustainable development. Using a qualitative research approach based on Grounded Theory, in total, 12 individuals participated in the study, representing a cross-section of stakeholders from both policy-making and implementation sectors. The findings reveal that SEA's effectiveness in Iran is hindered by political interference, weak institutional capacity, absence of standardized technical guidelines, deficiencies in legal and executive structures, lack of sustainable financial resources, poor environmental data quality, and inefficient decision-making processes. To address these challenges, eight strategic recommendations are proposed: (1) strengthening legal and executive frameworks, (2) enhancing specialized and organizational capacity, (3) ensuring sustainable financial resources, (4) increasing public participation and awareness, (5) improving environmental data management, (6) continuously updating EIA and SEA methodologies, (7) streamlining execution processes, and (8) establishing technical standards. Implementing these strategies will enhance SEA efficiency, reduce bureaucratic delays, strengthen stakeholder engagement, and improve transparency in decision-making. Furthermore, an improved SEA framework will contribute to reducing air, water, and soil pollution by ensuring proactive environmental risk assessments and integrating sustainability into development policies. This study highlights the urgent need for strategic, multifaceted reforms to strengthen SEA governance in Iran and ensure its alignment with global environmental standards and pollution management efforts.
The sugar industry generates wastewater with high organic content, presenting serious environmental concerns. Microbial fuel cells (MFCs) offer an eco-friendly solution by simultaneously treating this effluent and producing electricity. This study evaluated MFC performance through batch experiments, optimizing operational parameters such as pH, salt bridge concentration, and electrode material. Treatment efficiency was assessed using Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) measurements. Maximum BOD and COD removal efficiencies of 89.73% and 90.03%, respectively, were recorded at pH 6. The highest current output was observed at a salt bridge concentration of 1M KCl. Among the electrode materials tested-Aluminium, Copper, Iron, and Carbon-the Carbon-Carbon (C-C) pair produced the highest voltage output of 2.398 V. This research adhered to standard laboratory practices and ensured that no hazardous or pathogenic waste was released during experimentation. The findings reinforce the potential of MFCs as a sustainable technology for effective sugar industry wastewater treatment and renewable energy generation, with attention to environmental and ethical research practices.
The present research investigated the adsorption of Gold (Au(I)), Copper (Cu(II)) and Zinc (Zn(II)) ions from aqueous solution using a natural clay from Akjoujt region in Mauritania as an low cost adsorbent. The natural Akjoujt clay were characterized by several physical and chemical methods such as X-Ray fluorescence (XRF), X-ray diffraction (XRD), Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), BET surface Area, cation exchange capacity (CEC) and Thermal Gravimetric Analysis (TGA). The removal efficacy of the Akjoujt clay adsorbent for Au (I), Cu(II) and Zn(II ion was studied in batch mode as a function of contact time and temperature. Adsorption kinetics data were modelled using pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetics. The behaviour and the nature of Au (I), Cu (II) and Zn (II) adsorption were analysed by employing the Langmuir, and Freundlich isotherm models. The adsorption kinetics followed the PSO kinetics whereas the adsorption data fitted well with the Langmuir isotherm model. The adsorption capacities (qm) from the Langmuir isotherm for Au(I), Cu(II) and Zn(II) are found as 2.90, 7.93 and 6.45 mg/g respectively. The effectiveness of Akjoujt clay in the adsorption of the three metals from aqueous system was Cu(II) > Zn(II) > Au(I). The thermodynamic calculations suggested the spontaneous nature (Delta G degrees < 0) of the adsorption process, along with the endothermic characteristics (Delta H degrees > 0) in all cases. These findings highlight the promising potential of natural clay Akjoujt for efficiently adsorbing Au(I), Cu(II) and Zn(II) from aqueous solutions.
This study assessed the concentrations, distribution, sources and ecological risks of heavy metals in agricultural soils near industrial zones in Gazipur, Bangladesh. Thirty soil samples were collected in mid-January 2024 and analyzed for six heavy metals (Cr, Ni, Cu, As, Cd, and Pb) using inductively coupled plasma mass spectrometry (ICP-MS). Average concentrations (mg/kg) were: Cr (7.47 +/- 1.93), Pb (6.88 +/- 2.30), Cd (1.95 +/- 0.60), Cu (11.64 +/- 2.61), As (2.55 +/- 0.85) and Ni (17.87 +/- 5.08). All metals, except Cd, were below the permissible limits set by Dutch, Canadian, and Australian soil quality guidelines. Multivariate statistical analyses suggested mixed lithogenic and anthropogenic origins of heavy metals, with industrial activities being the dominant source. Contamination factors (CF), contamination degree (CD) geo-accumulation index (Igeo), enrichment factors (EF) and pollution load index (PLI) analysis indicated safe levels for most metals, but Cd posed significant contamination and ecological concern. The potential ecological risk index (PER) showed low to moderate risk, though some sampling sites exhibited high risk due to Cd. These findings provide critical insight for policymakers to mitigate soil contamination and protect environmental and human health.
This research provides an in-depth evaluation of biomass resources both in Iran and globally, emphasizing rural areas and the potential conversion of municipal solid waste and livestock manure into energy. It examines the current landscape of biomass energy production and its role as a sustainable alternative to fossil fuels. In Iran, considerable biomass is available through agricultural residues, animal waste, and municipal solid waste (MSW), although these resources remain largely underexploited. Conversely, evidence from South-East Asian nations (SEAN) reveals a more advanced utilization of biomass, presenting a clear opportunity for Iran to improve its approach. The study highlights that challenges related to regulation, technology, and market acceptance are key obstacles preventing the broader adoption of biomass energy in Iran. Moreover, recent progress, such as the launch of large-scale biomass facilities, indicates that a concerted shift toward renewable energy could bolster energy security, lower greenhouse gas (GHG) emissions, and drive socio-economic development. The results advocate for further research into more efficient biomass conversion technologies and the formulation of tailored, region-specific policies to unlock the full potential of biomass energy in Iran and similar regions.
The present study investigates the relationship between water quality parameters and microalgae diversity in a brackish lake ecosystem. Water samples were collected across four seasons, from October 2022 to July 2023, from the surface of six sites distributed throughout the seven northern lakes of Benghazi. Water quality parameters-including electrical conductivity, pH, temperature, alkalinity, and nutrient concentrations-were analyzed. Microalgae were identified, counted, and their abundance estimated using the Uterm & ouml;hl method. Microalgae diversity was assessed using Shannon, Simpson, species richness, and evenness indices. A total of 33 species belonging to 27 genera and five divisions were recorded. The most diverse group was Chlorophyta (49%), followed by Cyanophyta (21%), Bacillariophyta (12%), Euglenophyta (9%), and Dinophyta (9%). The highest species diversity, according to the Shannon-Weaver index, was observed in winter, while the lowest occurred in summer. The Simpson index was highest in autumn and lowest in summer. Principal Component Analysis (PCA) extracted two components from 14 environmental variables after Varimax rotation, explaining 46.47% of the total variance. Canonical Correspondence Analysis (CCA) identified two factors-F1 (41.35%) and F2 (17.77%)- which together accounted for 59.11% of the total data variance, with eigenvalues of 0.48 and 0.44, respectively. These results illustrate the relationship between microalgae species and environmental variables. Overall, the findings provide a foundation for developing sustainable conservation strategies to preserve the biodiversity of brackish lakes.
Increased anthropogenic activity in coastal areas has led to a significant decline in marine ecosystem quality, particularly due to the influx of nutrient-rich waste that triggers eutrophication. This study highlights a case of extreme pollution in Bima Bay, West Nusa Tenggara, marked by the appearance of massive brown sea foam in April 2022, covering an area of over 10 hectares. The research was conducted through water quality analysis, acute toxicity testing (LC50), microalgae identification, and satellite image interpretation. Results showed BOD concentrations of 20.8 mg/L, oil and grease at 28.5 mg/L, orthophosphate at 0.037 mg/L, and NO3-N up to 1.194 mg/L, all exceeding the quality standards set by PP No. 22 of 2021. Toxicity testing yielded an LC50-96 hour value as low as 0.081%, categorized as highly toxic. Microalgae identification revealed a dominance of the Diatom group, such as Nitzschia sp., Navicula sp., and Surirella sp., which thrived due to high nutrient content and favorable water conditions (pH 6.92 - 7.70, high light intensity). Analysis of Sentinel-2 and Landsat 8/9 imagery showed the appearance of foam beginning on April 24 and its disappearance after May 4, 2022. This pollution is closely related to massive land use changes in the upstream area for corn farming expansion, poor domestic sanitation systems, and the semi-enclosed geographical position of Bima Bay, which hinders seawater mixing and accelerates pollutant accumulation. These findings highlight the importance of pollution mitigation based on spatial planning and integrated waste management in tropical coastal areas.
The presence of Microplastics (MPs) in the environment poses a significant threat to both humans and ecosystems health. One common source of environmental MPs pollution is the sludge and effluent discharged by wastewater treatment facilities if no specific measures are implemented for post process MP removal. The purpose of this study is to investigate the MPs removal capacity under different conditions by analysis of MPs in the inlet wastewater, outlet effluent, and sludge of one of the wastewater treatment plants (WWTPs) in Qom city, Iran. Monthly sampling was conducted in spring and summer of 2022, resulting in analysis of a total of 18 samples from wastewater, effluent, and sludge. MPs were identified and separated according to established guidelines followed by further analysis using scanning electron microscopy (SEM) and & micro;-Raman spectroscopy. The average MPs concentration in wastewater and effluent were 710 +/- 34.67 MP/L and 51 +/- 4.42 MP/L, respectively, while it was 30.76 +/- 7.19MP/g in sludge. The treatment plant demonstrated an average MPs removal efficiency of 92.81%. Overall, polyethylene terephthalate (PET) and fibers were the most frequent type and shape of MPs identified across all samples. The dominant sizes of MPs in wastewater and sludge ranged between 250-500 & micro;m, while in the effluent, the MPs were primarily within the 250-100 & micro;m. Based on the findings, it is estimated that 2652 & times;106 MPs enter the environment daily through effluent and contributing to the pollution in air, soil, and surface water. The results of this study showed that sludge and effluent from WWTP are rich in MPs, and if used as fertilizer or to irrigate fields and crops, they can cause high levels of MPs to accumulate in the soil, polluting ecosystems and posing serious risks to organisms.
As global economic and human activities, as well as energy consumption, which have increased by 44% between 1971 and 2014, continue to rise, the concentration of greenhouse gas emissions (GHG) will continue to exacerbate global warming and environmental degradation. CO(2 )emissions (CO2E) are leading source of global warming, accounting for about 80% of all GHG. Rising sea levels are a consequence of increased CO2E. Despite the fact that OECD countries have achieved notable successes, particularly in sustainable development, through regulations and other initiatives for more than six decades, they continue to face significant environmental challenges. In addition, the economies of the OECD member States and a number of developing nations are still responsible for three-quarters of total emissions. This study analyses the influence of economic fitness (EF), energy efficiency (EE), economic growth (EG), and international trade (INT) on CO2E. It employs the CS-ARDL, two-way fixed-effect estimation techniques, and the second-generation methods of cointegration and granger causality for the analysis. The results indicate that EF, EE, and INT are important factors in curbing CO2E, while EG is responsible for the rising CO(2)Ein the short-run and the long-run. These findings imply that improving economic fitness and energy efficiency maybe a crucial component of CO(2)Emitigation.
Glitter, a type of primary microplastic, has multiple applications including in cosmetics, embellishments in arts and crafts, decoration items and jewelry. The current study was designed to determine the potential effects on ingestion of microplastics upon hematology, histology and DNA integrity in relation to varying doses in experimental groups of Mus musculus along with their retention within the body. Commercial glitter (Polyethylene terephthalate), (0.03 & micro;m in size) was selected and fed to experimental groups mixed with basal diet in escalating doses (0.0 & micro;g/kg, 100 & micro;g/kg, 200 & micro;g/kg, 400 & micro;g/kg and 800 & micro;g/ kg). Fecal matter was collected on daily basis and analyzed for amounts of MPs present in them. After a trial duration of 21 days, blood samples were collected following standard protocol and hematological parameters analyzed. Statistical analysis indicated no significant difference of doses upon blood profile at alpha = 0.05 except for Lymphocytes (p = 0.01) which showed a significant impact at higher doses i.e. 400 & micro;g/kg and 800 & micro;g/kg. Histological examination of Gastrointestinal Tract (GI) indicated degeneration and sloughing of mucosal cells, and necrosis in intestines of treatment group 3 and treatment group 4. Degeneration and disruption of villi was also visible in these groups. Likewise, DNA damage was noted to increase with increase in doses. It was also observed that the number of MPs present in excreta reduced as the dose increased.
The global spread of invasive aquatic organisms via ballast water discharge poses significant ecological and economic risks. Although various ballast water treatment systems (BWTS) are designed to mitigate this threat, the influence of ship-specific and operational parameters on treatment performance remains insufficiently understood. This study applies Structural Equation Modeling (SEM) to evaluate relationships among ship characteristics (gross tonnage, length, width), treatment system operational parameters (rated capacity, retention time, flow rate, total volume), and biological outcomes (concentrations of viable organisms >= 50 & micro;m and 10-50 & micro;m). Data were obtained from 59 International Maritime Organization (IMO)-compliant commissioning test reports collected during discharge via dedicated sample ports under IMO G2 guidelines. Organism concentrations were determined using second-generation Adenosine triphosphate (ATP) analysis, with thresholds aligned to the IMO D-2 standard. Initial one-way ANOVA tests revealed no significant differences in organism concentrations across ship types or treatment technologies. Multiple regression analyses identified modest linear relationships between certain ship or operational variables and biological outcomes but also showed inter correlations among predictors that could obscure their individual effects. To address these dependencies and investigate potential indirect pathways, SEM was employed. The final model achieved good fit and indicated that larger ships generally possessed greater treatment and operational capacity, which was associated with reduced concentrations of organisms in the 10-50 & micro;m size class. No significant effect was observed for organisms >50 & micro;m. These results highlight the need to align BWTS capacity and hydraulic exposure with vessel scale, while suggesting that supplementary strategies may be required to effectively control larger organisms.
Phosphorus eutrophication threatens freshwater ecosystems and food security in semiarid agricultural regions. The potential of low-temperature (<400 degrees C) lanthanum modification of steel slag to achieve high adsorption capacity, environmental safety, and regenerability for phosphate removal is uncertain. We synthesized lanthanum-modified steel slag at 400 degrees C and conducted structural characterization. We performed batch and fixed-bed column adsorption tests, supplemented by the USEPA Method 1312 leaching assessment across pH 2-9, five-cycle regeneration studies, Visual MINTEQ geochemical modeling, and ISO 14044-compliant life-cycle cost analysis. The material showed a phosphate adsorption capacity of 3.21 +/- 0.08 mg P/g at pH 7, a 90% improvement over pristine slag, maintained >= 80% performance across pH 5-9, and demonstrated lanthanum release of 0.0181 +/- 0.0009 mg/L at pH 2-90.5% below regulatory guidelines and the lowest for rare-earth adsorbents. The five-cycle regeneration process retained 82 +/- 2.1% of its capacity. Geochemical modeling revealed a dual-pathway mechanism: 60% reversible inner-sphere complexation and 40% irreversible lanthanum phosphate precipitation, accounting for superior performance. The manufacturing cost was USD 1.19 +/- 0.12/kg, 60-70% lower than conventional rare-earth synthesis, yielding a net present value of USD 0.47 million and a 23.6% internal rate of return over ten years. This study established quantified design principles for low-temperature rare-earth adsorbents, facilitated decentralized phosphorus recovery in resource-limited regions, and demonstrated unprecedented lanthanum immobilization through triple-mechanism passivation combined with regenerability and economic viability in smallholder agricultural systems.
This study investigates the role of soil chemistry, specifically pH, organic carbon (OC), organic matter (OM), and cation exchange capacity (CEC), in influencing the mobility and distribution of Th-232 radionuclides in abandoned mine soils using advanced machine learning (ML) models. Soil samples were collected from multiple locations across different seasons. Gaussian Process Regression (GPR), Long Short-Term Memory (LSTM) networks, Adaptive Neuro-Fuzzy Inference System (ANFIS), and Random Forest (RF) models were employed to predict Th-232 distribution, with feature selection identifying optimal model combinations (C1, C2, and C3). The performance evaluation of machine learning models revealed distinct patterns in predicting Th-232 distribution. The results indicate that GPR-C1 exhibited the highest predictive accuracy, with MAPE improving from 8.9909 to 3.0468 and MAE reducing from 3.5236 to 1.6044 during the verification phase. In addition, GPR-C1 emerged as the top-performing model during both training (RMSE = 7.0851, DC = 0.6482) and testing (RMSE = 4.5808, DC = 0.5848), demonstrating its robustness in capturing non-linear relationships between soil properties (pH, OC, OM, CEC) and Th-232 mobility. In contrast, RF models (RF-C1, RF-C3) exhibited the poorest performance (training RMSE > 11.5123; testing RMSE > 7.6855), likely due to their inability to resolve complex geochemical interactions, as evidenced by their low DC (<0.2) and PCC (<0.3) values. A notable observation was that several models exhibited lower RMSE in the testing set than in calibration, reflecting the reduced variance within the held-out site-season blocks; however, nested cross-validation and a leave-site-out analysis consistently identified GPR-C1 as the most reliable and accurate model. This aligns with field data showing higher Th-232 mobility during wet seasons due to leaching and runoff transport (p < 0.05). For instance, testing RMSE (4.5808) of GPR-C1 was significantly lower than its training RMSE (7.0851), reinforcing the role of seasonal dynamics in Th-232 redistribution. Therefore, this model demonstrates significant potential for accurately predicting Th-232 behaviour and distribution, crucial for environmental risk assessments. Hence, accurate predictions of 232Th distribution can guide targeted remediation efforts and inform land management practices, mitigating risks associated with Th-232 exposure.
This work investigated the impacts of C-Phycocyanin on Titanium Dioxide Nanoparticles (TiO2 NPs)-induced stress in alfalfa (Medicago sativa L.) plants. The study focused on evaluating the effects of TiO2 NPs on the vegetative growth, biochemical composition, oxidative stress markers, and DNA integrity of alfalfa plants. TiO2 NPs stressed the alfalfa plants in a concentration-dependent manner through decrease in plant height, branch number, leaf area, and biomass production. Biochemical parameters like chlorophyll, nitrogen, and potassium contents were reduced, revealing diminished physiological and photosynthetic activities. Contrarily, the co-application of TIO2 NPs and C-Phycocyanin mitigated the detrimental effects, as they promoted the growth and biochemical parameters recovery at low and moderate nanoparticle concentrations. TIO2 NPs treatment increased the level of MDA, and ROS) oxidative stress biomarkers, while C-Phycocyanin application decreased these indicators values, masking their scavenging potential. DNA integrity analysis through Comet Assay suggested that C-Phycocyanin effectively resist cells from TIO2 NPs -induced DNA damage and retain genomic stability. Therefore, co-application of C-Phycocyanin mitigated these adverse effects, demonstrating its potential as a natural biostimulant that enhances plant tolerance to nanoparticle-induced phytotoxicity.
