International Journal of Environmental Science and Technology最新文献

A newly developed bio-hybrid material comprising luteolin as a bioactive dye and a Zinc-Aluminum layered double hydroxide as an adsorbent was synthesized using two distinct methods. In the first method, Zinc-Aluminum layered double hydroxide was initially produced using the co-precipitation technique. Subsequently, the bioactive luteolin was intercalated onto the synthesized layered double hydroxide through an ion exchange mechanism. Response surface methodology and analysis of variance studies were employed to design experiments leading to achieve optimized adsorption onto the Zinc-Aluminum layered double hydroxide, considering effective variables like pH, dye concentration, layered double hydroxide weight, and operating time. Under the optimized conditions, the maximum adsorption efficiency (94.2%) and adsorption capacity (47.11 mg g⁻¹) were achieved. Kinetic studies indicated the pseudo-second order model characterized the luteolin adsorption, and the Langmuir model served as a suitable representation of the adsorption isotherm. In the second method, a co-precipitation approach was employed to simultaneously synthesize and intercalate luteolin onto layered double hydroxide with varying concentrations (5%, 15%, and 25%) under optimized conditions. The maximum adsorption efficiency and capacity reached 99.9% and 49.98 mg g⁻¹, respectively. Analytical characterization confirmed successful luteolin adsorption and stabilization of the layered double hydroxide. Furthermore, sustained luteolin release over an extended period was observed which attributed to its incorporation within the layered double hydroxide structure. The study also investigated the antioxidant activity of luteolin on the synthesized complexes, providing a comprehensive exploration of the bio-hybrid structure, Luteolin-Zinc-Aluminum Layered Double Hydroxide, with potential biomedical applications.

Benzimidazoles are important heterocyclic compounds that exhibit a wide range of pharmacological and biological properties. Among all, sensitivity to Lewis acids provide a possibility to act as a fluorescent detectors for senzing the cathions, radicals, highly reactive low-molecular species with hazardous effects to environment and human health. Herein, we present the design and synthesis of N-((1H-benzo[d]imidazol-2-yl)methyl)cinnamamide (I) for the detection of readily reactive thionyl chloride (SOCl₂). Treatment of SOCl₂ with a novel benzimidazole-based compound I is accompanied by immediate color change. Although the process is irreversible the change noticeable by eye is profitable for a simple and rapid protection against the SOCl₂ exposure at amounts harmful for surroundings and body. In the context of environmental issue, the chemical reaction between the detector I and thionyl chloride is beneficial for the safe waste disposal. Thionyl chloride is recaptured in the structure of I throughout the reaction leading to a formation of stable compound II. Incorporation of residual traces of SOCl₂ into the structure of organic-type detector I represents effective route to achieve non-reactive and non-damaging derivatives. Accordingly, the organic non-liquid waste is subsequently stored and disposed in a safe manner.

The recycling fruit wastes of banana, pomelo, and mangosteen as biosorbents for eliminating methylene blue dye (MBD) were investigated in this study by synthesizing 3 materials of banana (Musa ABB cv. Kluai ‘Namwa’) powder beads (BPB), pomelo (Citrus maxima (Burm.f.) Merr) powder beads (PPB), and mangosteen (Garcinia mangostana Linn) powder beads (MPB) and characterizing with several techniques. Their MBD adsorption performances were examined by a series of batch experiments, desorption experiments, adsorption isotherms, kinetics, and thermodynamics studies. MPB had a higher specific surface area and pore volume than BPB and PPB, whereas its pore size was smaller than theirs. All materials had amorphous structures. BPB had rough surfaces, whereas PPB had coarse surfaces with layer structures. MPB had rough surfaces with irregular shapes. They consisted of carbon, oxygen, calcium, chloride, and sodium. The chemical functional groups of hydroxyl, methine, carbonyl, and ether were detected in all materials. The pH_pzc of BPB, PPB, and MPB were 5.41, 5.00, and 5.05. MPB showed a higher MBD removal efficiency of 98.92% and adsorption capacity (q_e) of 6.59 mg/g than BPB and PPB, and all materials could be reused for 3 cycles with the adsorption efficiency of more than 61%. Their adsorption patterns and mechanisms were described by Freundlich and pseudo-second-order kinetic models. BPB and MPB were endothermic processes, whereas PPB was an exothermic process.

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Climate change has a recognized global effect on ozone concentration, yet its impact varies across regions and countries. Local studies are imperative for precisely evaluating the accurate, robust, and up-to-date relationship between climatic variables and ozone concentration at regional scale. In this work, we elucidate the spatiotemporal and seasonal variability of ground-level ozone (O₃) in Malaysia using backward trajectory and Generative Additive Model. Concentrations of O₃ and other air pollutants (NO₂, CO, SO₂ and PM_2.5) from a total of 43 air quality stations across the country from 2107 to 2020 have been analyzed along with the meteorological auxiliary data. Ozone pollution is susceptible in the Central, Northern and Southern of Peninsular Malaysia, and occurs at different times subject to the monsoon variability. In the Central zone, 60% of days during March and April had unhealthy ozone levels with a maximum daily averaged O₃ 73.5 ± 9.3 ppb. The backward trajectory analysis indicates that ozone pollution in the Central zone is strongly affected by northeasterly transboundary air pollution from Indochina and East China. The Generative Additive Model analysis highlights O₃ variability in the Central zone is possibly modulated by stratospheric air intrusion and PM_2.5 inhibitory effect that suppressed surface solar radiation and weakened O₃ production. Overall, the work advances the understanding of O₃ variability in Malaysia, provides valuable insights into complex interplay between O₃ concentrations and climatic variables, and offers a framework for future research in air quality modeling.

The global concern for e-waste necessitates comprehensive research, especially in educational institutions. This paper examines the case study of Ho Chi Minh City University of Technology (HCMUT), examining the generation, flow, and potential environmental impact of e-waste from 2024 to 2034. The research incorporates life cycle inventory (LCI) and material flow analysis (MFA) to estimate the volume and composition of obsolete electronic and electrical equipment (EEE). The study reveals a substantial increase in discarded devices at HCMUT, aligning with campus expansions. E-waste is estimated to generated 1.5 times from 16,792 kg in 2024 to 25,230 kg in 2034, emphasizing the urgency for effective waste management. MFA models delineate the flow of e-waste materials, emphasizing the need for targeted recycling measures. The examination of specific EEE types (projectors, computers, air conditioners, and lamps) reveals varying recyclability proportions, necessitating tailored management strategies. The absence of a specific e-waste management law in Vietnam, coupled with manual and unsafe processing practices, contributes to environmental and health hazards. The paper emphasizes the imperative for sustainable practices in higher education institutions (HEIs) and presents HCMUT's case as pivotal. The university's commitment to sustainable development is highlighted, underscoring the importance of integrating e-waste management into broader environmental strategies. As HEIs globally struggle with e-waste challenges, the study proposes a framework for effective management, incorporating LCI and MFA for informed decision-making. The results provide valuable insights for developing practical and sustainable e-waste management measures, guiding HEIs toward minimizing environmental impact while fostering a culture of responsible e-waste practices.

Industrial developments and settlements along the Siak River have affected the quality of the river water. Based on laboratory tests, the COD and BOD content of Siak River water still exceeds the standard set under Government Regulation No. 22 of 2021. This research was conducted to analyze the role of variations in the composition and size of materials of clay, fly ash, and sawdust, in synthesizing ceramic membranes for COD and BOD removal of Siak River water. These residual materials from pulp and paper industry were used for ceramic membranes synthesis and further applied in drinking water treatment. In this study, ceramic membranes with a diameter of 11 cm, a thickness of 0.5 cm, and a combustion temperature of 900 °C were obtained and the composition of clay, fly ash, and sawdust of the ceramic membranes was varied in terms of ratio, respectively, at 32.5%:60%:7.5%, 45%:45%:10%, and 70%:25%:5%. Meanwhile, the variations in the size of the materials were as follows: 60, 80, and 100 mesh. The obtained results have shown that the COD and BOD content of Siak River water was reduced during the filtration process using the ceramic membranes, with the greatest percentage reductions in COD and BOD content (48.9% and 64.6%, respectively). The highest removals percentage were recorded upon using the ceramic membrane M8 (with a composition of 60% fly ash, 32.5% clay, 7.5% sawdust and particle size of 100 mesh). This result indicated that the ceramic membranes can be effectively used for the targeted application.

The investigation of bio-liquid fuels as a sustainable fuel has garnered significant attention. However, because of high production cost, other co-products need to be investigated. The pretreatment process of second-generation (2G) bioethanol produces black liquor that contains lignin. In this paper, we report a direct bubbling and a two-step acidification process for lignin isolation from black liquor of the pilot scale bioethanol production and its utilization as lead adsorber. This research investigated how Pb (II) ions adsorbed onto new modified lignin recovered from black liquor called dimethylamine-soda lignin. Alkaline pretreatment at 150 °C and 5 kg/cm³ by using a 450 L reactor was used to extract the lignin from oil palm (Elaeis guineensis) empty fruit bunches (OPEFB). The acidic precipitation was achieved by adding 3% HCl until the pH reached 2, and the air bubbling was done at a rate of 2 L/min. By applying dimethylamine-acetone-formaldehyde to soda lignin in the Mannich reaction, lignin derivative was produced. The Fourier-transform infrared spectroscopy, scanning electron microscopy, and Brunauer, Emmett, and Teller methods were used to characterize all types of lignin. The analyses confirmed the formation of dimethylamine-lignin, as indicated by a 19-fold increase in the total nitrogen content in the modified lignin. Pb (II) adsorption was verified by pseudo-first-order and second-order reactions. Dimethylamine-soda lignin had the adsorption capability for lignin extracted from acid and the air bubbling technique, 6.0 and 6.8 mg/g, respectively. The outcomes demonstrate that the eco-friendly aminated lignin can effectively lower Pb (II) in the solution, making it a suitable adsorbent for removing lead from aqueous media.

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