98%
921
2 minutes
20
Simulated landfill bioreactors were established and operated for 635 days to investigate the dynamic release of seven siloxanes in landfill biogas (denoted by octamethyltrisiloxane (L3), decamethyltetrasiloxane (L4), dodecamethylpentasiloxane (L5), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6)). In total, 259.45, 252.73, 233.30, 80.40, 4.35, 1.67 and 1.10 mg of D5, D3, D4, D6, L4, L5 and L3 were discharged from 57 kg of municipal solid waste (MSW). More than 70 % of the siloxanes were released before day 119, indicating that the peak period of siloxane discharge occurred during the hydrolysis and acid production stage. The cyclosiloxanes (D3, D4, D5 and D6) were the dominant siloxane species in the biogas. The mass load of discharged cyclosiloxanes was more than 98 % of that of the total siloxanes. In addition to the variation in the concentration distribution profiles of the different siloxane species in the MSW, transformations among species may have an important effect on the release of siloxanes. The main transformation products were D3 and D4 with high release rates (>20 %) and high measured contents of trimethylsilanol (TMSOH) and functional microorganisms (Pseudomonas) were observed during landfilling. These results suggested that MSW degradation and transformation of siloxanes both drive the dynamic release of siloxanes during long-term landfilling.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.wasman.2024.05.038 | DOI Listing |
J Hazard Mater
August 2025
Environmental Health Science and Research Bureau, Health Canada, 251 Sir Frederick Banting Dr., Ottawa, Ontario K1A 0K9, Canada.
Silicone-based bakeware is widely used due to its heat resistance, flexibility, and non-stick properties. However, concerns have emerged regarding the potential migration and release of siloxanes from these products into food and indoor air during baking. This study evaluates human exposure to cyclic siloxanes via ingestion and inhalation, using silicone bakeware purchased on the Canadian market.
View Article and Find Full Text PDFDrug Deliv
December 2025
School of Pharmacy, Queen's University Belfast, Belfast, UK.
Silicone elastomers based on polydimethylsiloxane are biocompatible and non-biodegradable thermosetting polymers used in various drug delivery applications, including subdermal implants, vaginal rings, and intrauterine devices. Without exception, all marketed silicone elastomer drug delivery products provide sustained or controlled release of highly hydrophobic small drug molecules, since drug solubility in the silicone matrix is a prerequisite for molecular diffusion and release. We are interested in developing multipurpose silicone elastomer vaginal rings for local administration of metal ions-such as copper and zinc-for non-hormonal contraception and antimicrobial therapy.
View Article and Find Full Text PDFJ Drug Target
September 2025
Department of Pharmaceutics, Visveswarapura Institute of Pharmaceutical Sciences, Bengaluru, Karnataka, India.
This study presents the development of dissolving levonorgestrel-loaded microneedles (LMNs) incorporating a chitosan-β-glycerophosphate thermogelling system for sustained transdermal delivery of levonorgestrel (LNG) as a contraceptive. Polyvinylpyrrolidone K90 and Dextran 40 were included to enhance mechanical strength and controlled drug release. LMNs fabricated using poly dimethyl siloxane moulds exhibited uniform, sharp structures as confirmed by scanning electron microscopy.
View Article and Find Full Text PDFJ Environ Manage
August 2025
Bolu Abant Izzet Baysal University, Faculty of Engineering, Environmental Engineering Department, Gölköy, 14030, Bolu, Türkiye.
This study demonstrates the effectiveness of electro-dewatering (ED) technology in the partitioning of raw sludge and the transformation of Volatile Methyl Siloxanes (VMSs) with a focus on fundamental parameters throughout the ED process. In this context, the partitioning and volatilization mechanisms of VMSs within the framework of modern science and technology, emphasizing the role of ED in advanced sludge treatment, are explored extensively. Moreover, this study is the first to comprehensively examine the relationship between dependent (DS% content of dewatered sludge) and independent (operation time, pressure, applied voltage) variables in the ED process using an advanced experimental design matrix via Box-Behnken design.
View Article and Find Full Text PDFJ Vis Exp
July 2025
School of Mechanical and Robotics Engineering, Gwangju Institute of Science and Technology;
Polydimethylsiloxane (PDMS) double casting is widely used for replicating microscale structures, including microfluidic channels and biomedical microdevices such as Bio-MEMS. Despite its versatility, strong interfacial adhesion between PDMS layers often results in incomplete replication or structural damage, particularly in densely packed microfeatures. Conventional approaches to reduce adhesion, such as plasma or chemical surface modification, require specialized equipment and can be time-consuming and costly.
View Article and Find Full Text PDF