Carbon dioxide (CO₂) emissions are produced by the combustion of fossil fuels for power generation, automobiles, and other major industrial processes. Hence, there is a need for efficient CO₂ absorption using advanced materials and reactor systems within the framework of carbon capture and storage technologies. This work emphasizes the synthesis and characterization of amino acid-based ionic liquids (AAILs) for CO₂ (99.99% pure) absorption via a liquid foam-bed reactor (FBR) and semi-batch equilibrium studies (SBES). Seven different AAILs, namely [TETA][ALA], [TETA][LYS], [TETA][GLU], [TETA][ASP], [TETA][GLN], [TETA][MET], and [TETA][PHE], were newly synthesized. The AAILs were characterized using FTIR and Raman spectroscopy and ¹H and ¹³C NMR spectroscopy to confirm their formation. Physical properties such as viscosity and density were also presented. The highest and lowest densities of 1.1709 and 1.0646 g cm⁻³ were observed for [TETA][ASP] and [TETA] [ALA], respectively, among the synthesized AAILs. The application of AAILs in FBR and SBES for CO₂ absorption was evaluated under different experimental conditions. Parameters such as initial concentration, surfactant, pH, and AAIL regeneration were studied. [TETA] [LYS] gave the highest moles of CO₂ absorbed per mole of [TETA][LYS] used; the highest mole ratios of 0.442, 0.172, and 0.112 (dry basis) were observed at initial concentrations of 500, 300, and 100 mmol CO₂, respectively. Finally, the highest mole ratio of CO₂ per mole of [TETA][GLU] was 0.166, followed by 0.133 for [TETA][ALA], during desorption studies.
The National Industrial and Mining Company (SNIM) is facing significant dust emissions, raising serious environmental and public health concerns. This study aimed to characterize airborne dust emissions from mining activities and to assess their physicochemical and microbiological composition. Dust samples were analyzed and found to contain hazardous heavy metals, including lead, copper, nickel, and cobalt. A standardized measurement procedure was developed and applied in accordance with French Standard X 43-014 to quantify dust emission rates. The potential sources and causes of dust emissions were identified, and immediate preventive and corrective actions were proposed using the Failure Modes, Effects, and Criticality Analysis (FMECA) method. The results revealed exceptionally high dust emission levels at the Guelb El Rhein mine, exceeding the thresholds associated with highly polluted environments. In contrast, emissions at the Kedia d’Idjil mine remained close to regulatory limits and were comparable to levels observed in relatively livable environments. Microbiological analysis of dust particles revealed the presence of potentially pathogenic staphylococcal species, including Staphylococcus epidermidis, S. hominis, S. capitis, S. haemolyticus, S. lentus, S. auricularis, S. sciuri, and S. cohnii subsp. urealyticum. These findings highlight the combined chemical and biological risks associated with mining dust emissions and underscore the need for improved dust management strategies in mining environments.
This research provides a radioecological assessment of surface waters and bottom sediments in the vicinity of conserved and reclaimed uranium mining sites in Northern Kazakhstan. Activities of natural radionuclides were determined, and distribution coefficients, radiological hazard indices, committed effective dose, and ecological contamination indices were calculated to evaluate radionuclide mobility and associated environmental risks. Gross alpha activity increases downstream along the Kutunguz River, while uranium isotope activities exceed background levels by 8–10-fold, indicating ongoing radionuclide migration from the conserved Shantobe uranium deposit. In contrast, the Balkhashin quarry, a closed hydrological system, demonstrates substantial accumulation of ²²⁸Ra attributable to limited water exchange. Distribution coefficient analysis indicates high uranium mobility in flowing river systems and enhanced retention in closed water bodies. Although most radiological hazard indices remain within internationally accepted limits, localized radiological risk is observed in the quarry area. The committed effective dose from drinking water at the background site exceeds the WHO screening level but remains below the ICRP recommended limit. The obtained results indicate differences in the behavior of radionuclides in flowing and closed hydrological systems, as well as the persistent impact of conserved uranium mining facilities on aquatic ecosystems.
Municipal solid waste (MSW) management is a critical component of greenhouse gas (GHG) mitigation in landfill-dominated systems, where methane emissions are governed by cumulative waste deposition and delayed decomposition processes. Conventional assessments often emphasize end-state comparisons, which can obscure the long-term consequences of intervention timing, stock accumulation, and demand-driven non-linear dynamics. This study applies a system dynamics (SD) modeling framework to evaluate trajectory-based GHG mitigation pathways in Thailand’s national MSW system over a multi-decadal horizon (2024– 2050), with explicit consideration of methane legacy effects and tourism-driven variability in waste generation. The model represents MSW generation, waste routing, landfill stock accumulation, and delayed methane emissions using first-order decay logic. Tourism activity is incorporated as a time-varying external driver affecting waste generation flows, allowing demand fluctuations and non-linear responses to emerge without altering the underlying system structure. Four scenarios are analyzed to reflect alternative intervention timings and waste management pathways under a consistent modeling framework. Simulation results show that early intervention substantively reshapes emission trajectories by constraining landfill stock accumulation, which, within the defined system boundaries, acts as a critical leverage point for long-term mitigation. In contrast, delayed interventions, despite achieving similar diversion levels at later stages, retain substantially higher cumulative GHG emissions due to legacy effects embedded in previously accumulated waste. Tourism-driven increases in waste generation act as a stress amplifier, accelerating stock formation and magnifying emissions under landfill-dominant configurations, leading to disproportionate GHG responses relative to demand growth. Overall, the findings demonstrate that the performance of GHG mitigation in MSW systems is strongly shaped by path dependence, time delays, and nonlinear demand dynamics. Trajectory-based analysis provides essential insight into why latestage mitigation cannot fully reverse methane legacy effects, underscoring the importance of early structural change for achieving sustained emission reduction in landfill-dominated waste management systems.
The widespread overuse of petroleum plastics has led to serious environmental challenges. This has necessitated the pursuit of greener alternatives that would reduce or eliminate mankind’s unsustainable and toxic dependence on the recalcitrant petroleum plastics. Polyhydroxybutyrate (PHB) is a potential substitute candidate for the production of biodegradable plastics. In this study, Bacillus thuringiensis CICIM (B2031) was utilized for the production of PHB using the agricultural by-product corn silage as a carbon source. The corn silage was pretreated with dilute sulfuric acid. The acid-pretreated corn silage hydrolysate was used at different loadings, producing a maximum biopolymer yield of 53.43% PHB. This was compared with the untreated corn silage which gave a maximum yield of 28.63% PHB, under the same conditions. The extracted PHB biopolymer was characterized using FourierTransform Infrared Spectroscopy (FT-IR), ultraviolet–visible (UV-Vis) spectroscopy, and gas chromatography-flame ionization detector (GC-FID). This study revealed that corn silage (CS) can be utilized as a renewable carbon source for PHB production.
