The present study examines the relationship between the degree of solubilization and biodegradability of wastewater sludge in anaerobic digestion as a result of low-temperature thermal pre-treatment. The main effect of thermal pre-treatment is the disintegration of cell membranes and thus solubilization of organic compounds. There is an established correlation between chemical oxygen demand (COD) solubilization and temperature of thermal pre-treatment, but results of thermal pre-treatment in terms of biodegradability are not well understood. Aiming to determine the impact of low temperature treatments on biogas production, the thermal pre-treatment process was first optimized based on an experimental design study on waste activated sludge in batch mode. The optimum temperature, reaction time and pH of the process were determined to be 80 °C, 5 h and pH 10, respectively. All three factors had a strong individual effect (p < 0.001), with a significant interaction effect for temp. pH (p = 0.002). Thermal pre-treatments, carried out on seven different municipal wastewater sludges at the above optimum operating conditions, produced increased COD solubilization of 18.3 ± 7.5% and VSS reduction of 27.7 ± 12.3% compared to the untreated sludges. The solubilization of proteins was significantly higher than carbohydrates. Methane produced in biochemical methane potential (BMP) tests, indicated initial higher rates (p = 0.0013) for the thermally treated samples (k up to 5 times higher), although the ultimate methane yields were not significantly affected by the treatment.
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http://dx.doi.org/10.1016/j.watres.2016.11.055 | DOI Listing |
Polymers (Basel)
December 2024
College of Biological and Agricultural Engineering, Jilin University, Changchun 130022, China.
Corn stalk fibers extracted from cattle manure (CSFCM) represent a unique class of natural fibers that undergo biological pre-treatment during ruminant digestion. This study systematically investigates the optimization of CSFCM-reinforced friction materials through controlled silane treatment (2-10 wt.%).
View Article and Find Full Text PDFToxics
December 2024
Department of Forensic Science, Fujian Police College, Fuzhou 350007, China.
The growing popularity of e-cigarettes has raised significant concerns about the safety and potential abuse of these products. Compounds originally used in the medical field, such as etomidate, metomidate, and isopropoxate, have been illegally added to e-liquids, posing substantial risks to consumer health, and facilitating the misuse of illicit drugs. To address these concerns, this study developed a rapid and efficient method for detecting etomidate, metomidate, and isopropoxate in e-liquids using thermal desorption electrospray ionization coupling triple quadrupole mass spectrometry (TD-ESI/MS/MS).
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, PR China.
Microplastics (MPs) pose significant threats to ecosystems and human health due to their persistence and widespread distribution. This paper provides a comprehensive review of sampling methods for MPs in aquatic environments, soils, and biological samples, assessing pre-treatment procedures like digestion and separation. It examines the application and limitations of identification techniques, including microscopic observation, spectroscopic analysis, and thermal analysis.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Chemical and Biochemical Engineering Department, University of Western Ontario, London, ON, N6A 5B9, Canada; Civil and Environmental Engineering Department, University of Western Ontario, London, ON, N6A 5B9, Canada. Electronic address:
The convergence of sustainability and climate change has catalyzed the pursuit of inventive strategies for waste management and sustainable energy production. Hereby, we explored the effect of coupling biochar addition and thermal pretreatment in anaerobic mono-digestion and co-digestion of thermally pretreated thickened waste activated sludge (PTWAS) with food waste (FW). Six semi-continuous lab-scale digesters were operated for 161 days at various organic loading rates (OLR of 2, 3, 4 and 8 kgCOD/m/day) with and without biochar (BC) addition.
View Article and Find Full Text PDFWaste Manag
December 2024
Jiangsu Key Laboratory of E-waste Recycling, School of Resources and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, PR China. Electronic address:
There are hazardous substances such as chloride salts and heavy metals in the municipal solid waste incineration fly ash (WIFA). During thermal treatment, the concentrated chlorides promote the volatilization of heavy metals, increasing the ecological risk. The water washing method is also employed as a pre-treatment for WIFA, but a substantial volume of wastewater with high chloride content is produced that poses challenges for effective treatment.
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