Environment and Natural Resources Journal

Atmospheric Microplastics in Indoor and Outdoor Air: Abundance and their Potential as Vectors for Heavy Metals

2025-10-06T11:36:45+07:00

Microplastics (MPs) have emerged as pervasive atmospheric pollutants, yet their occurrence and characteristics in urban air environments remain poorly characterized. This study quantified the abundance, morphological features, polymer composition, and elemental associations of airborne MPs in indoor and outdoor environments in Marikina, Philippines. Airborne particles were collected using a respirable dust sampler and analyzed through microscopic observation, attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). Results revealed significantly higher MP concentrations in outdoor air (0.341±0.038 MP/m³) than indoors (0.155±0.106 MP/m³) (p=0.0454), with estimated daily intakes ranging from 0.5-3.2 MP/day indoors and 2.1-4.3 MP/day outdoors. Fibers were the predominant morphology in both environments, accounting for 80.0-95.7% indoors and 61.3-84.0% outdoors. Polymer analysis identified indoor MPs mainly as polyvinyl chloride (PVC, 50.0%), polyethylene (PE), and polyurethane (PU), whereas outdoor samples showed a broader diversity, including polyamide (PA), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), and high-density polyethylene (HDPE). Elemental analysis revealed the adsorption of toxic metals such as titanium (Ti), chromium (Cr), lead (Pb), mercury (Hg), and cadmium (Cd), with Pb concentrations reaching up to 18.13% in indoor PE fibers and Cr up to 18.29% in outdoor HDPE. These findings demonstrate that outdoor environments harbor higher concentrations and more chemically complex MPs, emphasizing the potential risk of human inhalation exposure. The study underscores the urgent need for monitoring airborne MPs and developing mitigation measures to reduce human and environmental health in urban areas.

Attenuation of Organic Matter in Landfill Leachate: Seasonal Characterization and Soil Column Evaluation

2025-09-05T17:14:43+07:00

Landfill leachate (LL) from landfills and open dumpsites poses significant risks to surrounding soils and water bodies. This study investigated seasonal variations in physicochemical and heavy metal characteristics of LL at the newly operational Bancharedada landfill site in Nepal using the Leachate Pollution Index (LPI). It also evaluated the attenuation of organic content, measured as chemical oxygen demand (COD), across different soil textures using fixed-bed column tests. Kinetics analyses employed the Yoon-Nelson model (YNM), Thomas model (TM), and Adam and Bohart model (ABM). The biological oxygen demand (BOD₅)/COD ratio ranged from 0.44 to 0.51, with higher values in the dry seasons and lower values during the monsoon, indicating rainfall-induced dilution of organic pollutants. The bed saturation time for COD removal was longest in clayey soil (35 days) and shortest in sandy soil (4 days). YNM provided the best model fit and was therefore applied for COD breakthrough prediction across soil textures. YNM rate constants (KYN) were lower in clayey soils and higher in sandy soils, thereby increase in breakthrough times (τ) and adsorption capacities (Qo) in clayey soils whereas the sandy soils shows the opposite trend, highlighting the strong influence of soil texture on COD attenuation potential.

Unified Green E-Waste Management Framework for Sustainable Campus Development: Case Study of Malaysian Public Universities

2025-09-30T22:08:27+07:00

Electronic waste (e-waste) has become the fastest-growing waste stream globally, presenting complex environmental and regulatory challenges that are particularly evident in higher education institutions. In Malaysia, public universities are significant contributors to e-waste generation due to their extensive reliance on information and communication technologies, laboratory equipment, and administrative devices. Although regulatory frameworks, such as the Environmental Quality (Scheduled Wastes) Regulations 2005, exist, current practices in universities remain fragmented, focusing largely on asset disposal under Ministry of Finance guidelines and neglecting gaps in behavioral, infrastructural, and policy integration. This study introduces the Unified Green E-waste Management Framework (UGEMF), a holistic model specifically designed for Malaysian public universities. The framework was developed through qualitative methods, including document analysis, in-depth interviews with key stakeholders, and a review of institutional practices, regulatory documents, and best-practice case studies. The findings highlight barriers, including limited awareness, bureaucratic constraints, and the absence of institutionalized policies, while also identifying emerging best practices, such as refurbishment initiatives, decentralized collection points, and cross-sector collaborations. By operationalizing circular economy principles within the higher education context, UGEMF contributes theoretically to sustainability and waste management literature, while offering practical guidance for policymakers and administrators. Its adoption can transform e-waste management in Malaysian public universities from fragmented compliance processes into comprehensive, integrated sustainability strategies. This approach supports national green growth targets and sustainable campus development.

Modeling PM2.5: Temperature Interactions Using Predator-Prey Dynamics

2025-11-10T14:43:42+07:00

This study introduces a novel application of the predator-prey concept to model and forecast daily PM2.5 concentrations, with PM2.5 treated as the prey and temperature as the predator. This formulation reflects the commonly observed inverse relationship between pollution levels and temperature in urban atmospheric environments. A dynamic equation was constructed to describe the rate of change in PM2.5, incorporating both intrinsic growth and the suppressive effect of temperature. Regular environmental cycles are also incorporated into the model structure. Parameters were estimated using daily observational data collected over a three-month period. The model successfully captures short-term variation and broader seasonal trends in PM2.5, despite relying on temperature as the sole external variable. This approach provides a simplified yet interpretable framework that explains how pollution levels respond to environmental drivers over time. It represents a conceptual shift from purely statistical models by offering an ecological perspective on air quality dynamics. Predictive validation yielded RMSE values of 15.7036 for PM2.5 and 0.9425 for temperature, demonstrating strong agreement with observed data. This is the first study to adapt predator-prey principles to describe and predict the interaction between temperature and PM2.5 on a daily time scale.

Implementation of the Groundwater Live Observation for Water-Quality (GLOW) in Bojong District, Indonesia

2025-12-09T10:29:40+07:00

Many developing countries still predominantly rely on conventional monitoring of groundwater quality parameters. Emerging technologies have shown significant potential for advancing automated water quality monitoring in recent years. This study developed the Groundwater Live Observation for Water-quality (GLOW) system, which leverages Internet of Things (IoT) technologies combined with water quality sensors. In future applications, this remote sensing-based groundwater monitoring system holds strong potential for detecting pollutant intrusion in water bodies. The GLOW system was tested during two periods, namely from June 2023 to November 2023 and from January 2024 to March 2024, in Bojong District, Sukabumi Regency, Indonesia. The system employed Aqua TROLL 500 sensors capable of measuring water temperature, electrical conductivity (EC), pH, salinity, and total dissolved solids (TDS). The data generated by the GLOW system were transmitted to a website server and subsequently evaluated against laboratory-based data using statistical analyses. The Wilcoxon Signed-Rank Test was applied to assess differences between the two approaches. Most parameters showed no statistically significant differences (p>0.05), except for TDS and salinity (p=0.02). The Bland-Altman analysis confirmed good overall agreement between the two methods, with small mean differences for pH (0.19), EC (8.45 μS/cm), water temperature (-0.34°C), salinity (0.02 PSU), and TDS (0.01 ppm). Future research should expand monitoring by including nitrogen and phosphorus compounds.

Exploring the Relationship between Climate Parameters and Water Salinity Fluctuations: A Case Study in Binh Chanh District, Ho Chi Minh City

2025-08-15T10:36:57+07:00

Climate change is expected to worsen drought conditions, which may elevate the risk of salinity intrusion in many regions of Vietnam. Therefore, this research analyzed the annual variations in water salinity in Binh Chanh District by employing the Modified Innovative Trend Analysis method, which interprets not only specific trends but also avoids distributional assumptions found in classical approaches, including normality, independence, and pre-whitening. Additionally, the study proposed a Sobol Index to investigate the relationship between salinity levels and weather variables from 2007 to 2024. The findings indicated a notable increase in annual salinity, reaching up to 8.12% at the Ong Thin station. In contrast, a significant decrease of less than 2% was noted, primarily at the Cong Kenh C station. While An Ha recorded a significant sensitivity value for mean temperature at 56.5%, salinity levels at the Cong Kenh C and Ong Thin stations were highly responsive to precipitation, accounting for over 77.2% and 69.6% of sensitivity, respectively. These findings enhance the understanding of salinity trends and provide a robust scientific basis for informing policy interventions related to land and water resource management, agricultural planning, and estuarine environmental governance in Binh Chanh District under accelerating climate change.

A Numerical Investigation of Perforated Inlet Baffle Configurations on Flow Behavior in a Rectangular Oil / Water Separator using CFD

2025-09-22T21:23:32+07:00

Gravity separation tanks are generally utilized to separate water and oil in treatment applications. The operating behavior of such tanks is likely to be sensitive to tank operation, as these factors will largely determine whether or not oil droplets stratify easily and float independently of water. Within the present investigations, the influences of several holes in the baffles on water and oil separation within a rectangular tank were explored through the utilization of a numerical model and the consequent simulation of fluid flow. Moreover, in order to ensure the credibility of the simulations, validation was carried out through utilization of a model based on work already conducted experimentally. FLOW-3D (version 11.04) software was applied to model a steady-state, incompressible flow within a two-dimensional (x-z) domain using the Reynolds Averaged-Navier-Stokes (RANS) equations. The RNG k-ε turbulence model was adopted to approximate the hydraulic behavior, while the volume of fluid (VOF) approach was employed to capture the air-water interface. In addition, the FAVOR (Fractional Area/Volume Obstacle Representation) technique was used to represent the geometric details of the perforated baffles. 2 perforated baffle geometry cases were explored: differing in the number of holes but with the same hole diameter in both cases. Performance was strongly validated through operational uniformity based on the standard deviation of horizontal velocity within the tank, and the flow field pattern was utilized to determine the characterization of the streamlines and recirculation areas. A kinetic energy analysis was carried out to illustrate turbulence in the flow approximation. The results indicated that an inlet baffle with fewer holes had significantly enhanced operating uniformity and lower turbulence compared with more holes, and correspondingly, these flow field patterns depicted more streamlined movement and lower recirculation areas.

Analyzing the Seasonal Relationship between Vegetation Variation and Land Surface Temperature Dynamics in Eastern Maharashtra

2025-10-26T21:30:43+07:00

Understanding land surface temperature (LST) change trend is very important in Eastern part of Maharashtra state, India as this region is undergoing rapid land-use change. Vegetation plays a critical role in regulating land surface temperature in such region. The main objective of this study is to analyze the vegetation change trend and investigate the seasonal relationship between vegetation variation and land surface temperature fluctuation from the years 2014 to 2022. Using Landsat 8 satellite imagery, the Normalized Difference Vegetation Index (NDVI) is derived to monitor vegetation variation and thermal infrared (TIR) bands is used to calculate LST. The methodology is divided into data collection, preprocessing, NDVI and LST calculation. Based on NDVI and adaptive vegetation classification, land use (LU) classification is carried out and finally correlation analysis between the various classes of LU, NDVI value with LST is calculated. The results suggest a clear seasonal pattern where the post-monsoon period has higher average NDVI values and lower average LST values as compared to the pre-monsoon periods. There was a declining trend of overall vegetation health throughout the study period, although 2022 showed a slight recovery in pre-season NDVI and improved vegetative health in post-monsoon dense vegetation classes. Correlation analyses consistently indicated a moderate-strong negative association (~ -0.2 to -0.5) of LST with vegetation cover (vegetation cooling effect) and a positive association (~ 0.1 to 0.5) with built-up areas (urban heat island effect). It highlights the importance of vegetation cover for local temperature management and has significant implications for the assessment of recent changes in the local environment.

Geological Analysis and Occupational Safety Risks in Traditional Oil Drilling in Ranto Peureulak, East Aceh, Indonesia

2025-12-26T11:24:18+07:00

Aceh has abundant natural resources, including oil and natural gas. One of these resources is located in Ranto Peureulak, East Aceh Regency. This area has abundant crude oil reserves. However, due to the lack of government permits, the local community relies on traditional oil drilling methods. The purpose of this study is to assess the impact of traditional oil drilling carried out by the local community in Ranto Peureulak, East Aceh, in terms of both occupational safety and environmental impact. This study was conducted at 20 drilling sites in Ranto Peureulak, East Aceh. Occupational safety risk data was obtained through direct observation and analysis. In addition, physicochemical analysis was also carried out by comparing the analysis results at the drilling sites with the standard quality values set by Government of Indonesia Regulation No. 22 of 2021. The results of this study indicate that traditional crude oil drilling poses an extreme level of risk to occupational safety and the environment. Physicochemical analysis shows that several drilling sites have test values exceeding the established thresholds. Therefore, it can be concluded that traditional oil drilling activities have a very serious impact, both on human health and the surrounding environment.

Quantifying Decadal Recovery in Small Scale Community-Based Mangrove Management (SSCM) in East Java, Indonesia, using Integrated Remote Sensing and Ecological Assessments

2025-07-14T10:45:43+07:00

This study examines ecological outcomes of small-scale community-based mangrove management (SSCM) in three locations in East Java: Clungup Mangrove Conservation (CMC, south coast), Penunggul (north coast) and Hijau Daun (small island). The primary objective is to evaluate the impacts of local community initiatives on mangrove ecosystem recovery over the past decade. Methodology combined remote sensing and field-based approaches. Machine learning google earth engine (GEE) was applied to assess past decade vegetation recovery using Normalized Difference Vegetation Index (NDVI), while raster analysis processed using R software to obtain net value change. To ensure compatibility between datasets, spatial harmonization was performed by resampling and aligning Sentinel-2 imagery to match Landsat 7 resolution using QGIS software. Field observations were conducted to assess the current ecological metrics, and descriptive analysis was carried out to connect restoration outcomes with management practices. Research findings indicate notable increases in net value change, with CMC showing the most substantial recovery (0.2-0.3), shifted from predominantly open or sparse areas to moderate or dense vegetation. Mangrove in Daun and Penunggul have ΔNDVI of 0-0.1, reflecting mild improvement in vegetation cover. Ecological assessments further revealed variation among sites. In Penunggul, diameter at breast height (DBH) of mangrove ranged from 2-16 cm (mean 7.70±3.34 cm), with average tree density of 2,300 ind/ha. CMC has mangrove density from 1,200-3,600 ind/ha and mean DBH 5.70±2.20 cm (range from 3.00-10.00 cm). Hijau Daun exhibited the lowest average density at 1,333 ind/ha, with DBH range from 2.00-37.00 cm (mean 9.27±7.24 cm).