Municipal solid waste (MSW) landfills play a big role in greenhouse gas (GHG) emissions, especially methane, contributing to global warming. However, this methane is also a promising renewable energy source. This study is the first to estimate the amount of landfill gas (LFG) emissions and the potential for energy recovery at three major landfill sites (LFSs) in Nepal: Sisdole, Pokhara, and Karaute Dada, using the Landfill Gas Emissions Model (LandGEM). The results showed that Sisdole emits between 57.86 and 60.21 million cubic meters (m3) of methane, Pokhara between 2.8 and 2.94 million m3, and Karaute Dada between 1.47 and 1.49 million m3. For 2025, the total revenue potential was estimated at 32.72-34.04 million United States Dollars (USD) for Sisdole, 1.59-1.66 million USD for Pokhara, and 0.83-0.84 million USD for Karaute Dada from energy generation and carbon credit. These findings highlight the vast renewable energy potential of Nepal's landfills. The study reveals that default LandGEM methane generation constant (K) values underestimate methane generation, especially in areas with high rainfall like Pokhara. It underscores the need for using a locally derived K value. Using locally calculated K values gives more accurate results and is important for better planning of methane recovery and energy projects.

This study proposes a novel valorization pathway for post-hydrolyzed food waste (PHFW) via black soldier fly larvae (BSFL) bioconversion and evaluates its suitability as a feedstock for BSFL lipid-based biodiesel production compared with untreated food waste (FW). Three feed types were prepared: (1) FW (−), untreated FW mixed with rice bran (RB) as the control; (2) FW (+), FW (−) with pH adjustment using CaCO3; and (3) PHFW (+), PHFW mixed with RB and pH-adjusted using CaCO3. FW (+) achieved the highest larval performance, with a waste reduction rate of 66.41%, bioconversion efficiency of 31.43%, waste reduction index of 3.89, and feed conversion rate of 2.83, while FW (−) showed the highest lipid yield (39.33%). PHFW (+) exhibited the shortest development time (20.17 days) and the highest biodiesel yield (69.34%), producing biodiesel with an acid number of 0.40 mg KOH/g and a calorific value of 38.54 MJ/kg. Normalized biodiesel production reached 23.83 kg/ton PHFW (+), presenting a preliminary demonstration of biodiesel production potential. Its defatted larval meal also contained 38.27% protein, highlighting the additional value beyond biodiesel production. These findings highlight the potential of PHFW valorization via BSFL bioconversion within a circular economy framework for sustainable resource recovery and biodiesel production.

Landfills serve as a significant source of microplastics (MPs) contamination, affecting the surrounding air, water, and agricultural soils. This study examined the seasonal variation of MPs in leachate, river water, and soil at Sisdole (old) and Banchare Dada (new) landfill sites (LFSs). MPs greater than 90 μm were enumerated using a stereomicroscope, and polymer identification was performed on a representative subset of particles using micro-Fourier transform infrared (FTIR) spectroscopy. Average MPs concentrations were higher at the new landfill, with values of 56 ± 07 MPs/L at Banchare Field and 44 ± 27 MPs/L at Banchare Tank, compared to 28 ± 11 MPs/L at Sisdole Pond in the old landfill. In river water, MPs increased downstream: 17 ± 12 MPs/L at Sisdole Upstream, 28 ± 22 MPs/L at Sisdole Downstream, and 34 ± 06 MPs/L at Banchare Downstream. Soil contamination was highest at Sisdole (351 ± 173 MPs/100 g), followed by Banchare (214 ± 70 MPs/100 g) and Banchare-Sisdole (157 ± 48 MPs/100 g). Statistical analyses, including a paired t-test for river water and a two-way ANOVA for soil samples, showed significant differences in MPs concentrations between the monsoon and premonsoon seasons in both river water and soil. Fibers were the dominant form of MPs in leachate, river water, and soil, whereas fragments were mainly within the 90-500 μm size range and fibers within the 1000-5000 μm range. Polyethylene terephthalate/polyester (PET/PES) accounted for 50% of the identified polymers, followed by polypropylene (PP, 20%), polyethylene (PE, 10%), and other polymers (20%). The polymeric composition suggests that textiles and degraded plastic packaging are the possible sources of MPs. Overall, the study identifies landfill-derived MPs as a possible source of pollution in nearby river and agricultural lands, underscoring the urgent need for measures, such as leachate treatment and improved landfill management practices by the relevant authorities.

Soil amendments, once valued for enriching the soil, have emerged as silent infiltrators, introducing microplastics (MPs) into the soil and posing significant threats to its health. This study investigates MP pollution in different soil amendments and topsoil samples treated with biogas digestate from Denmark and compares them with data from Thailand. Results revealed considerable variability in MP concentrations, ranging from 267 +/- 202 items/kg dry weight (dw) in compost derived from garden waste in Assens municipality (AC) to 19,067 +/- 1301 items/kg dw in biosolids (BS). Biopulp (BP) exhibited the highest total plastic concentration (143.86 mg/kg) among biowaste-derived soil amendments, as determined by Pyr-GC/MS analysis. Topsoil samples showed MP concentrations ranging from 225 +/- 35 to 1050 +/- 71 items/kg and 19.01 mg/kg to 12.31 mg/kg. Various MP morphologies and colours were detected in all the samples, indicating that these MPs originate from diverse plastic sources. Ten different polymer types were identified, with polyvinyl chloride (PVC) being the most prevalent across all samples. Smaller particles (< 300 mu m) were dominant. Comparisons between MP contamination in soil amendments from Denmark and Thailand highlight that MP pollution is a global issue, impacting both developed and developing nations. This finding suggests contamination can still occur in well-regulated systems despite strong legislation and circular economy practices. While Thailand could benefit from adopting selected Danish practices, a combined approach-leveraging technological innovation, effective policy, and public participation, is essential to address the complex challenges of MP pollution.

Persistent organic pollutants such as synthetic dyes represent a serious environmental challenge due to their toxicity and resistance to biodegradation, while conventional wastewater treatment methods often exhibit limited efficiency at low pollutant concentrations. Adsorption has therefore emerged as an effective alternative owing to its simplicity, low energy requirements, and versatility. In this study, magnetic chitosan nanoparticles were synthesized via an in-situ co-precipitation method and evaluated for the adsorption of methyl orange (MO) as a model azo dye. Structural and surface characterization by FTIR, XRD, SEM, and BET analyses confirmed successful magnetic functionalization and surface properties favorable for adsorption. Batch adsorption experiments conducted at an initial MO concentration of 30 mg L−1, adsorbent dosage of 1 g L−1, solution volume of 100 mL, near-neutral pH (≈ 6.9), and room temperature demonstrated rapid dye uptake, with equilibrium attained within 30 min. The equilibrium adsorption capacity reached 29.32 mg g−1, corresponding to a removal efficiency of 97.7

Microplastic (MPs) pollution in soil has been increasingly reported worldwide; however, data from Thailand remain very scarce, and the issue is largely unexplored. This study addresses that critical knowledge gap by investigating the abundance and characteristics of soil MPs across diverse land use types in Thailand. Topsoil samples were collected from 31 sites representing seven land-use categories: paddy fields, roadside areas, urban parks, forest, university area, sugarcane fields, and cassava fields. MPs concentrations ranged from 83 to 12,100 items/kg of soil, with an average of 3,303 ± 3,749 items/kg. Land use type significantly influenced MPs abundance, with roadside soils showing the highest levels, averaging 7,467 ± 4,020 items/kg, as confirmed by FTIR analysis, and 187.68 mg/g, as determined by pyrolysis–gas chromatography-mass spectrometry (Py-GC/MS). Conversely, cassava fields exhibited the lowest MPs abundance, with 100 ± 45 items/kg and 9.88 mg/kg. Spatial variability in MPs characteristics, including polymer type, shape, size, and color, also closely followed land use patterns. Particles smaller than 0.5 mm were the most dominant size class, while blue and transparent MPs were the most frequently observed colors. Among all soil samples, polyethylene (PE) was the most prevalent polymer (35

Ensuring safe drinking water is a basic need of human which align with SDG 6 but still remains a major concern in northern Bangladesh, where groundwater from tubewell is the primary water source. This study aimed to predict current potability of drinking water and mapping the contamination hotspot in Thakurgaon district within 40 tubewells sampling for lead. Each tubewell was pumped for five minutes before collecting samples. Samples were analyzed inorganic elements and trace metal including lead (Pb). To enhance predictive assessment, Support Vector Machine (SVM), Rasndom Forest (RF), and XGBoost machine learning (ML) models were developed using preprocessed water-quality data where RF was the best fit and was used for further spatial analysis. The RF model achieved an accuracy of 0.917, classifying 25

This study investigates how anaerobic granular sludge (AnGS) heat pretreatment duration (HPD, 0–1.5 h) at 100 °C and inoculum-to-substrate ratio (ISR, 0–0.5 v/v) interact to regulate Fe, Mg, and Ca availability and enhance hydrogen yield (HY) in the dark fermentation (DF) of food waste hydrolysate (FWH). A glucose solution (10 g/L) is used to assess HPD, while FWH evaluates ISR. ANOVA showed significant treatment effects for HY, and the Tukey test identified 0.5-h HPD and ISR 0.3 as optimal. 0.5-h HPD released Fe (35.50 mg/L), Mg (5.80 mg/L, and Ca (22.65 mg/L) from AnGS, yielding 0.53 mol H2/mol glucose. Under optimal combined conditions, the initial DF contains Fe (18.77 mg/L), Mg (73.00 mg/L), and Ca (346.62 mg/L), reflecting contributions from the inoculum and FWH. This condition improved HY to 0.60 mol H2/mol glucose equivalent, with butyric acid (3.43 g/L), acetic acid (0.68 g/L), and ethanol (0.11 g/L). Results highlight inoculum preparation and loading strategies to enhance DF-based waste-to-energy conversion.

The increasing accumulation of petroleum-based plastics and the large volume of agricultural and seafood processing wastes have raised serious environmental concerns worldwide. Valorization of biowastes into biodegradable films represents a promising strategy for waste management and circular economy development. In this study, agricultural and marine wastes were used to develop antibacterial biodegradable films based on microcrystalline cellulose (MCC) derived from durian rind (DR) and chitosan extracted from shrimp shells (SS). Composites films were prepared via solvent casting and evaluated in terms of mechanical properties, antibacterial activity, biodegradability, structural characteristics, and food preservation performance. Among the developed formulations, the MCC-DR-Chit-SS (20:80) film exhibited the most favorable properties, with consistent thickness (0.118 f 0.007 mm) and lowest coefficient of variation (6.34%), indicating good structural homogeneity. The film also demonstrated superior mechanical performance, including tensile strength (13.05 f 0.81 MPa), elongation at break (28.85 f 1.75%), and Young's modulus (40.0 f 0.33 MPa). Antibacterial testing revealed an inhibition zone of 3.8 f 0.5 mm, confirming effective antimicrobial activity. In addition, the film exhibited promising environmental performance, achieving 57% biodegradation in soil within 30 days. Structural analyses using FTIR and XRD confirm strong hydrogen bonding interactions and relatively high crystallinity (77.2%), contributing to improved mechanical stability. Furthermore, food preservation tests showed that tomatoes wrapped with the films had significantly lower weight loss during 14 days of storage compared to unwrapped controls. Overall, the results showed the feasibility of valorizing durian rind and shrimp shells into sustainable biodegradable packaging materials within circular economy systems.

The investigation of microplastics (MPs) in terrestrial environments has increased, including studies on atmospheric MPs in indoor and outdoor settings. However, the lack of a well-established and definitive methodology has complicated comparing the results. This article examines previous research on atmospheric MPs, providing an overview of researchers' methodologies. Additionally, it discusses the diversity and limitations of these approaches while suggesting the most effective practices identified thus far. The existing studies vary in qualitative and quantitative methods, such as sample collection, the choice of digestion and density separation techniques, MPs enumeration methods, and analytical procedures. Due to these procedural differences, the results cannot be easily compared. Establishing a standardized procedure would facilitate result comparison and enhance the reliability and credibility of atmospheric MPs studies.

Microplastics (MPs) are detected ubiquitously in aquatic environments worldwide, with wastewater treatment plants (WWTPs) serving as significant pathways for their entry. This study investigates MP removal efficiency and suggests improvements in a conventional municipal WWTP in Bangkok, Thailand. Wastewater samples were collected using a volume-reduced method and filtered into three size ranges (0.05-0.5, 0.5-1.0, and 1.0-5.0 mm). Particles bigger than 0.5 mm were assessed for abundance using an optical microscope and identified for polymer types using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, while smaller particles were analyzed using fluorescence microscopy and micro-FTIR. The average concentration of MPs entering the WWTP was 16.55±9.92 MPs/L, whereas the concentration discharged into the environment was 3.52±1.43 MPs/L. The resultant MP removal efficiency of the Bangkok WWTP stands at approximately 78%, a figure lower than that of WWTPs in developed countries. This discrepancy is attributed to the absence of a primary clarifier within the Bangkok WWTP and an under-designed grit channel. Thus, the implementation of a filter system using activated carbon is suggested. Based on the calculations, 21 filter units are required for the Bangkok WWTP to improve MPs’ removal effectiveness. This study provides vital data on the presence of MPs in a Bangkok WWTP, emphasizing challenges that impede effective removal efficiency. Additionally, this study proposes potential solutions to enhance the removal of MPs and address these issues.

This study optimized dilute sulfuric acid thermo-hydrolysis of dried food waste (FW). Key hydrolysis factors were systematically varied, such as acid concentration, solution-to-solid ratio, oil solidifier addition, agitation, temperature, and reaction time. Multi-objective optimization was employed to maximize reducing sugar yield while minimizing the formation of inhibitory compounds, 5-hydroxymethylfurfural (HMF) and furfural, in the hydrolysate. A two-step optimization approach was used: screening experiments to identify active factors and numerical optimization of a desirability function in Design-Expert 13.0 to find optimal factor configurations in order to achieve the desired objective values. The optimal factor configurations (1.53 % H2SO4, 6 mL H2SO4/g dried FW, 1.49 g oil solidifier, 0 rpm, 80 degrees C, 60 min) achieved a composite desirability value of 0.80, yielding hydrolysate with 35.43 g/L reducing sugars, 0.14 g/L HMF, and 0.55 g/L furfural, with prediction errors below 10 %. The hydrolysate also had proteins (2.65 g/L), NaCl (0.30 g/L), and metals (Mg, Zn, Fe, Cu, Mn, Mo, Ni, Co) in beneficial amounts, while Cr and Cd remained within safe levels. These findings advance FW valorization by producing a fermentation-friendly hydrolysate for sustainable biohydrogen generation.

This study investigated the impacts of compost-hosted plastics and microplastics (MPs) on the growth and development of three economic crop varieties (lettuce, tomatoes, and radish) and assessed their bioaccumulation in edible parts under realistic environmental conditions. Four different composts, previously analyzed for their plastics and MPs content, were applied to the soil substrate to grow crops. Compost contaminated with the highest MP loads negatively impacted early plant growth, resulting in smaller overall plant size. Similarly, at the harvesting stage, the same compost exhibited the highest levels of free proline and total flavonoids in line with reduced plant growth. Photosynthetic pigment concentrations remained unaffected across treatments. Crop responses varied, with lettuce showing the most pronounced adverse effects across all growth stages. MPs were detected in edible plant tissues, with an average of 118 ± 136 particles g−1 dry weight in lettuce (leaf tissues), 140 ± 130 particles g−1 dry weight in radish (storage root tissues), and 81 ± 90 particles g−1 dry tissue in tomatoes (mature fruit tissues), as identified through Nile Red tagging and polymer analysis via micro-FTIR. Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) revealed an average MP mass of 2.2 mg g⁻1 dry weight in radish storage tissues. These findings suggest that MPs can accumulate in edible parts of vegetable crop species even during short-term cultivation periods, highlighting the need for further research on the long-term accumulation with risk assessment of human health and the adverse effects of MPs on yield loss in agricultural production.

Microplastic (MP) contamination in drinking water has emerged as a pressing environmental and public health concern. However, its behavior across treatment and urban distribution systems remains poorly understood, particularly in rapidly growing megacities. This study investigates MPs' prevalence, removal efficiency in a major water treatment plant (WTP) in Bangkok, Thailand, and through the urban water distribution network. Seasonal samples were collected at four treatment stages, clarification, filtration, and chlorination, in a conventional WTP, and at five household taps located 3-11 km downstream in the distribution system. MP concentrations in raw water reached 114 +/- 46 items/L in the dry season and 56 +/- 11 items/L in the rainy season. The WTP achieved an overall MP removal efficiency of 75-81 %, with filtration being the most effective stage. However, residual MPs persisted in treated water, with concentrations ranging from 14 +/- 8 items/L during the rainy season to 22 +/- 18 items/L in the dry season. Notably, MP levels increased significantly with distance from the WTP, peaking at 66 +/- 27 items/L at the farthest household, suggesting secondary contamination within the distribution system. Fragments were the most abundant MP morphology, while PP, PE, and PET were the dominant polymer types. Small-sized MPs (<100 m) were prevalent, raising concerns about human exposure and treatment limitations. This study highlights the need for integrated water quality management addressing both treatment efficiency and distribution infrastructure. The findings serve as a reference for improving water safety in Bangkok and other rapidly urbanizing cities worldwide.

Capacitive deionization (CDI) presents a sustainable solution for heavy metal remediation, where electrode material choice is critical to performance. This study elucidates the distinct trade-offs between Faradaic and non-Faradaic electrochemical strategies. To illustrate the difference, modified materials were synthesized via a hydrothermal method on an activated carbon fiber felt (ACF) substrate. In this study, the ACF grafted with MnO2 nanostructures (ACF/MnO2) served as a pseudocapacitive material, while the ACF grafted with ZnO nanostructures (ACF/ZnO), was designed to enhance non-Faradaic mechanism. Although the pseudocapacitive electrode (ACF/MnO2) demonstrated improved adsorption compared to pristine ACF, its efficacy was ultimately surpassed by the non-Faradaic pathway. The findings reveal the superiority of the electrical double-layer capacitance pathway, with the ACF/ZnO electrode achieving remarkable adsorption capacities of 34.1 mg/g (Cu2 +) and 23.8 mg/g (Ni2+) in a mixed-ions solution within a CDI cell, significantly surpassing both pristine ACF and ACF/MnO2. The efficiency of the ACF/ZnO was enhanced due to ZnO nanostructures amplifying the local electric field, intensifying electrostatic attractions, and improving surface-active sites. Furthermore, the MCDI cell outperformed the CDI cell by enhancing ion selectivity and reducing co-ion effects, boosting the ACF/ZnO electrode's Cu2+ adsorption capacity to 42.7 mg/g and showing similar improvements for Ni2+. This work highlights that integrating ZnO nanostructures is a more potent strategy for Cu2+ and Ni2+ removal than the MnO2-based pseudocapacitive pathway for advanced CDI systems.

Capacitive deionization is a highly effective and potential approach for removing harmful substances from wastewater. This study investigated the impact of integrating MnO2 nanostructures onto activated carbon felt material (ACF/MnO2) by a hydrothermal technique to eliminate both Cr(VI) and Cr(III) under various conditions. It indicated a notable rise in the specific capacitance of the prepared material, with ACF/MnO2 exhibiting 65.8 F/ g as compared to ACF with 31.5 F/g for the Cr(VI) electrolyte. ACF/MnO2 demonstrated superior efficacy compared to ACF under similar initial concentrations and pH. During the charging phase at 5th cycle, a significant adsorption amount for Cr(VI) (8.5 mg/g) compared to Cr(III) (3.0 mg/g) was observed for ACF/MnO2. After undergoing 9 cycles at 1.2 V, the adsorption capacity of ACF/MnO2 reached 7.9 mg/g, surpassing the pristine ACF at 6.7 mg/g for Cr(VI) removal. The recovery rate during the discharging phase for Cr(III) at 65.4 % was higher than the 63.3 % recovery rate for Cr(VI) using ACF/MnO2 at 10th cycle. Moreover, the adsorption capacity and recovery rate for Cr species improved with increased potential. This study highlights the possibility of incorporating MnO2 nanostructures into activated carbon to remove Cr(VI) and Cr(III), offering an environmentally advantageous and sustainable solution through CDI.

Domestic wastewater treatment systems can be expanded to reclaim non-potable water for toilet flushing. As current reclamation relies on a fossil-based energy mix, integrating cleaner energy sources is essential. This study compares the environmental impacts of non-potable water production under baseline (Sc-1) and future energy mix scenarios (Sc-2) in a treatment plant in Thailand. Under Sc-1, renewable and non-renewable energy shares were 20.51

Microbial fuel cells (MFCs) have gained interest due to their potential for direct electricity generation from organics in wastewater. On the other hand, algal systems are prominent biological nutrient recovery (as algal biomass) technologies. In MFCs, algal photosynthesis provides a promising method of generating oxygen for the cathodic reaction with enhanced electricity generation; thus, these two systems can be integrated for efficient bioproduct generation. After treating for the organic contents in the anodic chamber of MFC, the nutrient-rich effluent can be utilized as the algal growth medium in the cathode chamber. Furthermore, the algal cathode chamber can be connected with an external photobioreactor to enhance the stability of the electricity output when conducting under light/dark regimes. While the dead algal biomass has been used as the organic feed for the exogenous anodic bacteria, the live microalgae have been attempted to use as the electron donor in the anodic chamber.

Atmospheric microplastics (MPs) deposition in indoor and outdoor environments has yet to gain significant attention in Bangkok, Thailand. Outdoor MPs deposition is a potentially severe issue as it can contaminate agricultural land, water bodies, and water treatment plants. Similarly, indoor MPs can enter the human body during inhalation and ingestion as an individual spends most of the time indoors. This study employed a passive sampling method, followed by digestion, density separation, Nile red (NR) tagging, and micro-Fourier Transform Infrared Spectroscopy (FTIR) analysis to identify the abundance and characteristics of MPs in indoor and outdoor (urban, semi-urban, and industrial) air in Bangkok, Thailand. This study revealed an average indoor MPs deposition of 154 ± 62 particles/square meter/day (p/m2/d). Fragments (68