Overcoming the oxidation stability of biodiesel has been a significant challenge, especially after an extended storage period. To test a major factor affecting biodiesel quality, eight different conditions consisting of water at a concentration of 500 ppm and tert-butylhydroquinone (TBHQ) concentrations of 500, 1000, and 2000 ppm, in combination, were added to palm biodiesel, with no-water-added treatment as the control. Samples were kept in dark storage and air-limited at room temperature for 52 weeks with an initial carbon residue of 0.05 wt%. Every sample was periodically taken for property examination, which included the percentage of fatty acid methyl ester (FAME), iodine value (IV), kinematic viscosity (KV), acid value (AV), and oxidation stability. The properties of the samples with 500 ppm of water-added biodiesel exhibited the most significant degradation, even though oxidation stability (starting from 43.37 h) remained higher than 10.00 h after 32 weeks. The IV dropped 48.43% from 49.92 to 25.56 g I₂/100 g. The KV increased 6.14% from 4.56 to 4.84 cSt. The AV rose from 0.45 to 1.09 mg KOH/g. Biodiesel with 2000 ppm TBHQ added was stable for 22 weeks, with all properties under standard values. However, biodiesel in the same condition but with water contamination, its stability was reduced to 16 weeks.

We investigated the synthesis and characterization of biodegradable films composed of poly (lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT), with lignin as a natural additive and dicumyl peroxide (DCP) as a compatibilizer. The PLA/PBAT ratio of 70:30 was optimized and the DCP was incorporated at different concentrations to enhance interfacial adhesion. The effects of lignin addition (0.005–0.02%) on the mechanical, thermal, and biodegradation properties were evaluated using SEM, FTIR, XRD, and TGA analyses. The optimal formulation had improved tensile strength, elongation at break, and thermal stability, with the highest degradation rate of 44.22% after 90 days of soil burial. Life cycle assessment using SimaPro software (SimaPro 9.1.1.1) and ReCiPe 2016 Midpoint indicated that the film containing 0.005% lignin had the lowest environmental impact. The primary environmental concerns were marine and freshwater ecotoxicity, associated with solvent use. Based on the results, incorporating small amounts of lignin enhanced the biodegradability and reduced the environmental footprint of the PLA/PBAT films, highlighting their potential for sustainable packaging applications.

Chiang Mai is one of the most famous tourist destinations in Thailand. It is currently included on a UNESCO list of tentative World Heritage sites. If approved, this designation may lead to benefits such as additional tourists visiting Chiang Mai but may also cause more problems. This research investigates potential economic, sociocultural and environmental impacts that this designation may have on the Chiang Mai Old Town district. The study area is composed of six temples with high value as tourism destinations. The impacts are analyzed using both quantitative and qualitative methods to identify positive and negative results. The social and cultural impacts were mixed. Although becoming a World Heritage site would offer increased opportunities to educate foreigners about Thai culture, it might denigrate local culture by treating it as just a commodity for foreigners. The economic impact results show that income would be higher, but so would the cost of living in the area. Although there would be positive environmental impacts such as better management of the historic site ecosystem, the amount of non-biodegradable waste in the area would increase. Furthermore, analysis of life cycle assessment (LCA) data on this tourism area indicates that environmental impact levels would depend on the number of visitors. In order to provide sustainable tourism in the study area, we also propose policy making guidelines.

Wastewater containing heavy metals and dyes poses serious environmental risks. This study developed a multifunctional composite by coating polyurethane foam (PUF) with milled activated carbon (mAC) and a zirconium-based metal–organic framework (Zr-MOF) for the simultaneous removal of hexavalent chromium (Cr(VI)) and Congo red (CR). The composite was synthesized using a hydrothermal method to grow Zr-MOF on the surface. The SEM analysis confirmed the successful incorporation of mAC and surface modification with Zr-MOF, which resulted in increased surface roughness and porous morphology. XRD and FTIR confirmed the presence of organic ligands connected to the metal structure and the functional groups of each component in composite materials. The optimum conditions for Zr-MOF/mAC/PUF adsorption (nearly 100% removal) in the binary Cr(VI)/CR solution (50 mg/L each) were 25 °C, pH 9, and 150 rpm for 24 h. The Zr-MOF/mAC/PUF was hydrophilic with a swelling ratio of 2.64 g/g. The thermodynamic investigation of Zr-MOF/mAC/PUF resulted in 141.6218 kJ/mol for Cr(VI) and 166.111 kJ/mol for CR of ΔH° (rapid adsorption), negative ΔG° (spontaneous adsorption), a high positive value of ΔS° (disorder structure) and low activation energy (approximately 2.5 to 2.8 kJ/mol). After analyzing the isotherm and reaction kinetics, the possible mechanism could be endothermic physicochemical adsorption and pseudo-second-order kinetic behavior, with electrostatic attraction and diffusion control. The study of 6-times-reused Zr-MOF/mAC/PUF adsorption identified as a decrease of 7.55 percentage point without changing notable morphology and functional groups, based on SEM and FTIR.