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Molecular-Level Insights into the Degradation of Dissolved Organic Matter from Cyanobacteria-Impacted Water by Electro-Oxidation and Electro-Fenton

Mon, 01 Jan 2024 00:00:00 GMT

Title: Molecular-Level Insights into the Degradation of Dissolved Organic Matter from Cyanobacteria-Impacted Water by Electro-Oxidation and Electro-Fenton Authors: Angga, Aji; Lin, Lin, Jr. Abstract: Algal organic matter (AOM) generated from cyanobacteria-impacted reservoirs poses a high risk to drinking water. Electrochemical oxidation is an emerging treatment technology expected to be effective in removing AOM. This study presented the removal of AOM extracted from Microcystis aeruginosa (MA) using electro-Fenton (EF) and electro-Oxidation (EO) employing boron-doped diamond (BDD), modified graphene-Fe2O3 (GFe) anode and graphite felt (GF) cathode. Results indicate that H2O2 generation by BDD and GFe in 30 min behave similarly. The BDD-EF and BDD-EO treatment results shows that both EO and EF are applicable with varying efficiencies, to remove extracellular organic matter (EOM), intracellular organic matter (IOM), and mixed AOM suspension. The AOM removal was appears to be influenced by an electrochemical reaction affecting the hydrophobicity change of the AOM. Furthermore, a remarkable degradation of IOM is observed to be higher than that of EOM and a mixture of EOM and IOM, accounting for 85%, 78%, and 48% respectively. Specifically, for AOM suspensions, the soluble microbial product-like (SMPL) substances and low molecular components (<10(4) Da) fractions are predominantly degraded by EF by both BDD and GFe anodes. The performance of GFe anode is lower than the BDD anode in reducing the AOM. In EOM and mixed AOM suspension, higher molecular components (>10(4) kDa) and humic substances are reduced in EF and EO processes. However, low molecular components in AOM suspension can be significantly removed by EF alone. In conclusion, the degradation of AOMs by electrochemical oxidation is subject to the molecular fractions of AOM.

Unveiling The Potential of Microwave Plasma Treated Char For Sustainable Automotive Shredder Residue (ASR) Management and Reduced Ecological Risk Of Cadmium

Mon, 01 Jan 2024 00:00:00 GMT

Title: Unveiling The Potential of Microwave Plasma Treated Char For Sustainable Automotive Shredder Residue (ASR) Management and Reduced Ecological Risk Of Cadmium Authors: Ngo, Thi-Huyen-Tran; Wang, Ya-Fen; Chang, Tien-Chin; You, Sheng-Jie Abstract: Introduction This study explores the effectiveness of microwave plasma pyrolysis in reducing heavy metal concentrations, specifically cadmium, in automobile shredder residue (ASR).Methods The ASR was subjected to plasma pyrolysis at microwave power levels ranging from 800 to 1000W, resulting in a significant decrease in heavy metal concentration in the char. Utilizing the Bureau Communautaire de R & eacute;f & eacute;rence (BCR) sequential extraction method, a standardized procedure developed by the European Commission, we assessed the chemical speciation and matrix properties of the char. The results indicated that microwave plasma treatment effectively decreased the bioavailable forms of cadmium. After 6 minutes of pyrolysis at 1000W, the exchangeable and acid-soluble fractions (F1) dropped to 10%, while the reducible fraction (F2) fell to 12%.Results This treatment resulted in a substantial increase in the oxidizable (F3) and residue (F4) fractions, which reached 27% and 51%, respectively. Importantly, the potential ecological risk of cadmium decreased significantly, with the risk index (Er) dropping from 164.91 to 28.45, aligning with Taiwan's regulatory standards for non-hazardous waste.Conclusion These findings suggest that microwave plasma pyrolysis is a promising and sustainable approach for the disposal of ASR, offering an environmentally friendly alternative for waste management. This study provides valuable insights for policymakers, environmental scientists, and industries seeking effective solutions for ASR treatment.

Advanced oxide-stabilized zirconia ceramics for flue gas filtration in air purification systems

Wed, 01 Jan 2025 00:00:00 GMT

Title: Advanced oxide-stabilized zirconia ceramics for flue gas filtration in air purification systems Authors: Lee, Yen-Yi; Li, I-Cheng; Kogularasu, Sakthivel; Huang, Bo-Wun; Wang, Ya-Fen; Masimukku, Srinivaas; Pham, Minh-Thuan; Chang-Chien, Guo-Ping Abstract: Air pollution, largely driven by industrial activities and fossil fuel combustion, poses a critical threat to both the environment and public health. Addressing emissions, particularly from factories operating at extremely high temperatures, demands advanced filtration technologies capable of withstanding such severe conditions. Ceramic filters have emerged as a promising solution due to their superior thermal stability, chemical resistance, and mechanical durability. Among these, oxide-stabilized zirconia (OSZ) ceramics have garnered significant attention for their potential in high-temperature flue gas filtration. OSZ ceramics enhance the intrinsic properties of zirconia, such as its high melting point and mechanical strength, while stabilizing its phases to prevent performance-degrading phase transformations. This review comprehensively examines the role of phase transformations in ZrO2 materials, alongside the fabrication methods, structural characteristics, and advantages of ZrO2 ceramics in air filtration applications. The review examines various stabilizing agents used to maintain phase stability and optimize material performance under extreme conditions, highlighting the benefits of OSZ in flue gas filtration. Additionally, it covers recent advancements in OSZ synthesis and application, addressing critical limitations such as production challenges and the environmental impacts of large-scale use. The discussion emphasizes the move toward sustainable development in air filtration technologies. Finally, the review provides a forward-looking perspective on future research needs, aiming to further optimize OSZ ceramics for more effective and widespread industrial air pollution control, with a focus on improving performance, scalability, and environmental sustainability.

The investigation of mechanism isoniazid adsorption onto cassia fistula-based activated carbon

Mon, 01 Jan 2024 00:00:00 GMT

Title: The investigation of mechanism isoniazid adsorption onto cassia fistula-based activated carbon Authors: Murti, Restu Hikmah Ayu; Jawwad, Muhammad Abdus Salam; You, Sheng-Jie; Wang, Ya-Fen Abstract: The utilization of activated carbon as an efficient adsorbent is well-established, driven by its porous structure and expansive surface area. This study investigates the potential of Cassia fistula (Golden shower) as a precursor for activated carbon synthesis using K2CO3 activation, leveraging its organic properties known for high porosity and adsorption capacity. This research aims to investigate the feasibility of utilizing Cassia fistula-derived activated carbon (GSAC) for isoniazid removal from water. The study encompasses a two-step activation process-chemical and physical-with varying parameters to optimize surface area and porosity. The carbonization process involves hydrothermal and pyrolysis techniques with controlled conditions. The temperature used in this study is based on the TGA analysis to examine its thermal stability. Batch experiments examine the adsorption equilibrium and kinetics of isoniazid onto GSAC samples, revealing high adsorption capacity and rapid equilibrium attainment by GSAC 1:1 (700 degrees C). The study culminates in the identification of a strong chemical bond between GSAC and isoniazid, implying efficient adsorption potential as confirmed by FTIR and SEM analysis before and after adsorption. The adsorption characteristic is examined with an isotherm and kinetic model. The highest predicted GSAC capacity reaches 219,807 mg/g, emphasizing its promising adsorption capabilities. This work underscores Cassia fistula-based activated carbon as a viable, cost-effective, and eco-friendly adsorbent for isoniazid removal, with implications for diverse applications. The synthesis process parameters, activation methods, and insights into the adsorption mechanism contribute to the understanding of effective adsorbent production and enhance the potential of activated carbon for various industrial contexts.