Anaerobic digestion and fermentation processes in wastewater sludge treatment are limited by several factors, including the slow breakdown of complex organic matter and solubilization of solids. In this study, thermochemical pretreatment of thickened waste activated sludge using high temperature (>170 °C) was investigated to understand the impact of the pretreatment on the volatile fatty acids (VFA) production and its fractions during the fermentation process. Furthermore, the influence the thermochemical pretreatment on sludge disintegration and methane recovery was investigated. A range of acidic and alkaline conditions over the pH range of 4.5-10 was examined. Sludge (pH adjusted) was exposed to hydrothermal pretreatment (HTP) at a temperature of 170 °C for 30 min. Pretreated samples were then subjected to batch fermentation and methane potential tests which revealed that acidic and alkaline conditions resulted in increased sludge solubilization during HTP. Acidic conditions were associated with a higher VFA production yield of up to 185 mg chemical oxygen demand/g total chemical oxygen demand. Alkaline conditions led to a higher methane production yield where the maximum yield (276 mL CH/g total chemical oxygen demand) was found to occur at pH 10. Therefore, alkaline sludge used for fermentation has shown technical and economic feasibility for sludge carbon recovery.
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http://dx.doi.org/10.2166/wst.2022.368 | DOI Listing |
Viruses
December 2024
Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, Florida Campus, Roodepoort 1709, South Africa.
Pregnant women living with HIV (PWLWHIV) are at an increased risk of developing obstetrics complications such as pre-eclampsia (PE). Antiretroviral therapy (ART) remains the standard treatment for PWLWHIV and non-pregnant women. However, its use has been associated with adverse liver conditions, particularly hepatotoxicity, often marked by elevated liver enzymes (LEEs) as demonstrated by an increased aspartate transferase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) in PWLWHIV on ART.
View Article and Find Full Text PDFPlants (Basel)
January 2025
Departamento de Agronomía, Edificio Celestino Mutis (C-4), Campus de Excelencia Internacional Agroalimentario de Rabanales (ceiA3), Universidad de Córdoba, 14071 Córdoba, Spain.
Iron (Fe) deficiency is among the most important agronomical concerns under alkaline conditions. Bicarbonate is considered an important factor causing Fe deficiency in dicot plants, mainly on calcareous soils. Current production systems are based on the use of high-yielding varieties and the application of large quantities of agrochemicals, which can cause major environmental problems.
View Article and Find Full Text PDFPlants (Basel)
January 2025
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.
Soil salinization severely restricts the growth and development of crops globally, especially in the northwest Loess Plateau, where apples constitute a pillar industry. Nanomaterials, leveraging their unique properties, can facilitate the transport of nutrients to crops, thereby enhancing plant growth and development under stress conditions. To investigate the effects of nano zinc oxide (ZnO NP) on the growth and physiological characteristics of apple self-rooted rootstock M9-T337 seedlings under saline alkali stress, one-year-old M9-T337 seedlings were used as experimental materials and ZnO NPs were used as donors for pot experiment.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
School of Biomedical Engineering and Imaging, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, China.
The problem of antibiotic abuse and drug resistance is becoming increasingly serious. In recent years, polydopamine (PDA) nanoparticles have been recognized as a potential antimicrobial material for photothermal therapy (PTT) due to their excellent photothermal conversion efficiency and unique antimicrobial ability. PDA is capable of rapidly converting light energy into heat energy under near-infrared (NIR) light irradiation to kill bacteria efficiently.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Infant Health, University of Genoa, 16132 Genova, Italy.
Background/objectives: This study aims to assess the effects of combined hormonal contraceptives (CHCs) on bone metabolism markers. It primarily measures osteocalcin and additionally examines other bone health markers, seeking to determine their responses to estrogen-progestogen treatments.
Methods: This study involved a comprehensive evaluation of the pertinent literature and a meta-analysis explicitly conducted on data describing women of reproductive age.
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