Environment and Natural Resources Journal

Comparative Analysis of Dissolved Air Flotation and Sedimentation Processes for Treating High Turbidity Waters in Colombia

J. P. González-Galvis, A. M. Jaramillo, B. Pacheco — Thu, 20 Aug 2026 00:00:00 +0700

Dissolved air flotation (DAF) is a prominent technology that permits the treatment of water using higher hydraulic loading rates and lower retention times than sedimentation (SED). This study presents a comparative evaluation of DAF and SED for the treatment of two high-turbidity surface water sources (14-50 NTU) in Colombia. The water samples analysed were collected from the Chiquinquirá River (CR) and the Quebrada Madron Creek (QM), both located in Boyacá, Colombia. The optimal coagulant dosages were identified as 30 mg/L of aluminium sulphate for CR and 60 mg/L for QM using jar testing. Under these conditions, the turbidity removal efficiencies were 86% for DAF and 93% for SED in CR, and 91% for DAF and 93% for SED in QM. The apparent colour removal reached 86% for CR and 83% for QM. The removal of the ultraviolet absorbance at 254 nm (UV₂₅₄), used as a surrogate for natural organic matter (NOM), was 67% for SED and 64% for DAF in CR, with both processes achieving 73% removal in QM. Overall, SED consistently outperformed DAF in turbidity removal for both source waters, while the apparent colour and NOM reductions were comparable between the two technologies. The findings from this work provide valuable insights for optimizing the clarification processes in drinking water treatment plants managing high-turbidity surface waters in Colombia.

Sargassum-Derived Bioplastic for Sustainable Packaging: Evaluation of Mechanical, Thermal, and Barrier Properties

Nur Syazwina Kamarozaman, Dzulaikha Khairuddin, Nasaie Zainuddin — Thu, 16 Jul 2026 00:00:00 +0700

Plastic pollution remains a critical environmental issue due to the persistence of petroleum-based plastics in natural ecosystems. This study evaluates Sargassum seaweed, an abundant coastal biomass in Malaysia, as a renewable feedstock for biodegradable bioplastic production. To overcome the inherent limitations of alginate-based bioplastics, glycerol 12.6% (w/w, relative to polymer mass) has been incorporated as a plasticizer, with calcium chloride (2% w/v) as a cross-linking agent. Bioplastic films were produced via alginate extraction, film casting, and drying, and characterized through tensile testing, differential scanning calorimetry (DSC), water absorption, grease absorption, and biodegradability analyses. The modified Sargassum-based bioplastics exhibited enhanced tensile strength (maximum force up to 6.67 N), improved elongation at break (up to 31.33%), and increased thermal stability, with a melting temperature of 160°C and degradation onset at 190°C. Swelling, biodegradation, and oil uptake behaviors were governed by the interplay between hydrophilic diffusion and calcium-mediated cross-link stabilization. Complete biodegradation was observed within 30 days in soil. These findings demonstrate that formulation optimization allows Sargassum-derived bioplastics to achieve balanced mechanical performance, barrier properties, and environmental degradability. This will enhance their potential for sustainable single-use packaging applications.

An Appraisal of Green Gross Provincial Product of a Tourist Island - An Analysis Focusing on Phuket

Mon, 20 Jul 2026 00:00:00 +0700

This study incorporated provincial input-output tables into the environmental assessment process for Phuket - an island with an economy based largely on tourism. The life cycle assessment approach was employed considering five impact categories including climate change, fossil scarcity, water, eutrophication and land use for green gross provincial product (GGPP) calculation. Degradation cost and depletion cost originating from global warming and fossil resource scarcity were the main contributors. The results indicated that for a tourism-based economy such as Phuket, industries associated with tourism, such as accommodation and food service activities, wholesale and retail trade and repair of motor vehicles, as well as transportation and storage are highly profitable, but also impose heavier environmental burdens compared to other sectors. The sectoral GGPP of electricity, gas, steam, and air conditioning supply, as well as water supply, sewerage, waste management and remediation activities, involved more in local residents’ living, accounted for 25% and 50% of the sectoral gross provincial product (GPP), respectively. In 2015, Phuket GGPP was 160 billion THB, corresponding to 96% of the Phuket GPP. As Phuket relies heavily on its beautiful environment to bring economic value, it is imperative to protect it against environmental damages especially irrecoverable ones.

Suitability of Characteristic Wastewater Treatment Technologies: An Approach to Water Environment Protection in Major River Basins in the Former Binh Thuan Province, Vietnam

Phu Huynh, Thi Hue Nguyen, Thi Minh Ha Tran — Wed, 15 Jul 2026 00:00:00 +0700

In 2025, Binh Thuan Province was merged into Lam Dong Province as part of a broader restructuring initiative by the Vietnamese government. In the former Binh Thuan Province, Vietnam, increasing pollution pressure in river basins (where wastewater is received) requires identifying and applying wastewater treatment technologies suitable to the actual situation of the wastewater sources. This study conducted a multi-criteria analysis (MCA) combined with the weighted sum method and visualized through radar charts to assess the suitability of treatment technologies, identify operational incidents, evaluate impact levels and prioritize rehabilitation of wastewater treatment systems (WWTSs) currently applied to five typical wastewater types: domestic, industrial, seafood processing, livestock and hospital wastewater. A set of criteria comprising 22 sub-criteria in four groups (technical, environmental, economic, social) is applied and the criteria are quantified based on field surveys and expert consultations. Results showed that domestic WWTS achieved the highest score (75/100) reflecting stable performance and a high level of suitability, while seafood processing WWTS scored lowest (50.625/100) due to high costs and unstable efficiency. Industrial WWTS (68.125/100), livestock WWTS (64.375/100) and hospital WWTS (68.75/100) systems performed moderately, with good technical outcomes but constraints in cost, energy use and emissions. Recurrent incidents such as aeration failures, sludge flotation and odor generation were common, though generally remediable. Seafood processing and industrial WWTS were prioritized for urgent rehabilitation. This study provides essential data and a practical MCA-based decision-support framework to improve existing WWTSs under local environmental and operational conditions, thereby supporting water resource protection in Vietnam’s river basins.

Developing a Machine Learning Based Classification Model for Heavy Metal Contamination Levels in Mangrove Sediments

Harry Irawan Johari — Tue, 21 Jul 2026 00:00:00 +0700

Mangrove ecosystems play an important role in mitigating heavy metal pollution in coastal environments; however, direct assessment of their phytoremediation potential commonly relies on intensive field sampling and laboratory analyses. This study develops a machine learning-based prediction model to classify heavy metal contamination levels in mangrove sediments as a supporting tool for phytoremediation planning. A publicly available sediment dataset obtained from Kaggle, consisting of 300 samples with concentrations of Pb, Zn, Cr, Cu, and Ni, was used as a methodological testbed. Data preprocessing included feature normalization, label encoding, and class balancing using the Synthetic Minority Over-sampling Technique (SMOTE), followed by an 80:20 train-test split. Four classification algorithms Random Forest, Support Vector Machine (SVM), K-Nearest Neighbors (KNN), and XGBoost, were evaluated using accuracy, precision, recall, and F1-score metrics. Random Forest and SVM achieved the highest classification performance (92.5% accuracy), while KNN showed the lowest accuracy (81.5%). Feature importance analysis identified Cr, Pb, and Zn as the most influential variables in contamination level classification. Although the dataset is not site-specific and lacks ecological metadata, the results demonstrate the technical feasibility of machine learning models for sediment contamination classification. This study is positioned as a methodological proof-of-concept and highlights the need for future research integrating field-validated sediment data, mangrove species information, and biological uptake indicators to support robust phytoremediation assessments.

Growth Responses and Phytoremediation Capacity of Colocasia esculenta under Drought Conditions in Pb-Contaminated Soil

Wed, 22 Jul 2026 00:00:00 +0700

Phytoremediation is an effective, plant-based strategy for removing heavy metals from contaminated environments under various conditions. This study examines how lead (Pb) pollution and drought stress affect Colocasia esculenta’s physiological reactions and capacity to accumulate Pb. Plants were grown for 45 days under two soil moisture conditions (100% and 50% field capacity) and treated with 100 mg/kg Pb. The findings indicated that drought stress significantly diminished root growth, whereas Pb exposure exhibited no significant effect (p>0.05). No significant differences were observed in stem height, dry plant biomass, and relative growth rate (RGR) values (p>0.05). Under the combined Pb exposure and drought condition, the chlorophyll content and chlorophyll fluorescence parameters (PI and Fv/Fm) did not change. Under drought conditions, translocation factor (TF) levels were less than 1 (0.45-0.56) for the first 30 days; yet, following 45 days, they were more than 1 (1.17). Under drought stress, the bioaccumulation factor (BAF) values were over 1 (1.99-5.14), suggesting a high potential for Pb accumulation. All of these indicate that C. esculenta is resistant to Pb and has the capacity to phytoremediate Pb-contaminated dry soils.

Heavy Metal Content in Pavement Mushrooms Harvested within the Urban Area of Sarajevo (Bosnia and Herzegovina) and an Assessment of Associated Health Risks

Tue, 11 Aug 2026 00:00:00 +0700

This study investigated the ability of pavement mushrooms (Agaricus bitorquis (Quél.) Sacc.) to uptake heavy metals (Cu, Zn, Pb, Cr, Cd, and Ni) from the soil in Sarajevo’s urban area and the potential health hazards related to their consumption. The levels of tested heavy metals in soil and mushroom samples were determined using the flame atomic absorption spectroscopy technique. The phytoextraction potential was estimated using bioaccumulation factor (BAF) analysis, while the evaluation of the non-carcinogenic, long-term risk to human health through the consumption of the studied mushrooms was performed using the Target Hazard Quotient (THQ) value. The study revealed that particular soils within the urban zone of Sarajevo are contaminated with Cu and Pb. The average content of tested heavy metals in the fruiting bodies of pavement mushrooms decreased in the order of Cu > Zn > Pb > Cr > Ni > Cd, regardless of the soils from which the mushrooms were collected. The BAF values obtained in this study indicated that pavement mushrooms have a high ability to accumulate Cd and Cu, while showing a limited ability to absorb Pb and Ni. The THQ values for all heavy metals analysed in pavement mushrooms were considerably lower than one for both adults and children, suggesting that consuming pavement mushrooms gathered from experimental sites poses no non-carcinogenic health risks related to the heavy metals studied.

Integrating Design Thinking into Household Organic Waste Management: A Participatory Approach Toward a Circular Economy in Cirebon City, Indonesia

Fri, 21 Aug 2026 00:00:00 +0700

Household organic waste management in many Indonesian cities remains dominated by linear collect-transport-dispose systems, limiting the implementation of circular economy principles. In Cirebon City, low community participation and limited source separation remain key challenges. This study aims to integrate the Design Thinking framework into the assessment of household organic waste management behavior to support the transition toward a circular economy. A mixed-methods approach was applied, combining a quantitative survey of 300 households and participatory qualitative observations involving 30 respondents from three active community-based waste banks. Five behavioral indicators awareness and understanding, attitudes toward the program, actual waste management practices, willingness to participate, and perceptions of circular economy benefits were measured using a Likert scale questionnaire. Data were analyzed using descriptive statistics and Spearman’s rank correlation analysis. The results show a significant positive relationship between awareness, willingness to participate, and perceived benefits of the circular economy (ρ=0.395; p<0.01). Field implementation of the Design Thinking stages (Empathize Test) resulted in a 23% increase in community participation, improved perception of economic benefits, and the formation of habitual organic waste sorting behavior. Prototype trials using three types of dry materials (sawdust, charred rice husk, and raw rice husk) indicated that sawdust was the most effective, maintaining composting temperature stability (38-42°C) and producing mature, odor-free compost. This study contributes a participatory behavioral assessment framework that integrates Design Thinking into household organic waste management. The findings provide practical implications for local governments and community-based programs in strengthening circular economy implementation at the household level.

Strategic Framework for Driving Thai Universities toward Net-Zero Emission: A Case Study of Khon Kaen University

Watchara Pattanawiwattanaporn, Choopong Thongkumsamut — Tue, 18 Aug 2026 00:00:00 +0700

The transition of higher education institutions toward carbon neutrality has become an important component of national climate strategies. In Thailand, although several universities have begun conducting greenhouse gas (GHG) inventories, significant gaps remain in Scope 3 accounting, monitoring systems, and strategic planning frameworks that support long-term decarbonization. This study develops an integrated strategic framework to guide universities toward net-zero pathways, using Khon Kaen University (KKU) as a case study. A mixed-methods approach was employed, combining a systematic literature review, gap analysis, emissions clustering, and design-factor synthesis aligned with international standards, including the IPCC Guidelines, the GHG Protocol Corporate Standard, and ISO 14064-1. Data from Thai university reports and national emission factors were analyzed to classify institutions using hierarchical clustering based on energy intensity, emission intensity per student, sequestration capacity, and commuting emissions. The results reveal that Scope 3 emissions—particularly commuting and procurement—remain insufficiently reported across many institutions, limiting comparability but representing a major mitigation opportunity. The study proposes a University Net Zero Planning Tool that integrates emissions inventories, clustering-based benchmarking, and a design-factor matrix linking emission drivers to prioritized interventions. Application to KKU demonstrates both high operational emissions and substantial land-based sequestration potential. The framework offers a transferable decision-support model for universities in developing-country contexts seeking structured pathways toward carbon neutrality and net-zero targets.

The White Sands of Tutong - A High Quality Sand Suitable for Photovoltaic Applications

Wed, 26 Aug 2026 00:00:00 +0700

The renowned White Sands of Tutong in Brunei Darussalam, situated on the island of Borneo, have long been recognized as a potential source of glass-grade sand. As Brunei Darussalam seeks to diversify its economy, these sand deposits are gaining attention as a valuable mineral resource for sustainable development. Lithological investigations showed that the deposit is geologically more heterogeneous than anticipated, with the groundwater table close to the surface and the presence of red-brown sand indicating higher iron concentrations in current or former water-table fluctuation zones. This study investigated the chemical properties of the sand via ICP-OES, and XRF, which confirmed the high purity of the silica sand with low concentrations of iron. The glass produced from the raw sand exhibited a solar transmittance of 90.2%, making it suitable for photovoltaic applications. The sand should be shielded from any further development, like housing development and any development should carefully weigh the economic versus the ecological value of the sand as it also supports a rare tropical heath ecosystem.