This paper assesses anaerobic digestion of waste activated sludge (WAS) at low pH to enhance phosphorous solubility. Batch biochemical methane potential tests were conducted at a pH range of 5 to 7.2 in two separate sets (two different WAS samples collected from municipal WWTP). Low pH (<5.7) caused a significant (p = 0.004) decrease in methane potential (B0) up to 33% and 3.6 times increase in phosphorus release compared to neutral pH (7-7.7), but with no major change in methane production rate coefficient (khyd). The loss in methane yield was mainly due to decrease in hydrolytic capability rather than inhibition of methanogenesis with volatile fatty acids being <300 mgCOD L(-1) and soluble COD <1300 mgCOD L(-1) even at low pH. While pH did not influence the acetoclastic community (Methanosaeta dominated), it was the primary driver for the remaining community (p = 0.004), and caused a loss of diversity and shift to Clostridia.
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http://dx.doi.org/10.1016/j.watres.2015.05.062 | DOI Listing |
Sci Total Environ
January 2025
Department of Environmental Health and Engineering, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, United States. Electronic address:
Extracellular electron transfer (EET) plays an important role in maintaining redox balance in both natural and engineered anaerobic microbial systems, driving key biochemical processes such as energy generation, bioremediation, and waste degradation. While EET has been characterized in a limited number of microbes and applied in anaerobic digestion and bioelectrochemical systems, further research is needed to explore its mechanism across a broader range of microbial species and anaerobic processes. This review highlights advanced modeling frameworks that provide deeper insights into EET mechanisms and dynamics, aiming to optimize research efforts and minimize time and resource expenditure.
View Article and Find Full Text PDFWater Sci Technol
January 2025
The Institute of Applied Research, The Galilee Society, Shefa-Amr 2020000, Israel; Agrobics Ltd, Shefa-Amr 2020000, Israel; Prof. Ephraim Katzir Department of Biotechnology Engineering, Braude College of Engineering, Karmiel 2161002, Israel.
The advanced anaerobic technology (AAT), developed based on an immobilized high-rate anaerobic reactor, was applied as a pretreatment of municipal wastewater (WW) at Karmiel's treatment plant in Israel. The demonstration-scale AAT (21 m) system was operated at a flow rate of 100 mday municipal WW mixed with olive mill wastewater (OMW) (0.5 mday) to simulate the scenario of illegal discharge of agro-industrial WW.
View Article and Find Full Text PDFWater Sci Technol
January 2025
Departamento de Biotecnología y Ciencias Alimentarias, Instituto Tecnológico de Sonora (ITSON), 5 de Febrero 818 sur, Ciudad Obregón, Sonora 85000, México E-mail:
Granular activated carbon (GAC) and GAC modified with anthraquinone-2-sulfonate (AQS) were used as conductive materials during the anaerobic digestion of swine wastewater (SW). The electron transfer capacity (ETC) in the GAC-AQS was 2.1-fold higher than the unmodified GAC.
View Article and Find Full Text PDFBioresour Technol
January 2025
School of Environment, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. Electronic address:
Carbon chain elongation offers a promising pathway for converting waste resources into caproate. However, challenges in yield and selectivity have limited its broader application. To address these limitations, anaerobically digested sludge-derived biochar (ADS-B) was incorporated into the carbon chain elongation process.
View Article and Find Full Text PDFJ Environ Manage
January 2025
CALAGUA - Unitat Mixta UV-UPV, Departament d'Enginyeria Química, Universitat de València, Avinguda de la Universitat s/n, Burjassot, Valencia, 46100, Spain.
Most microplastics (MPs) end up in the biosolids produced in wastewater treatment plants (WWTPs) and can pose contamination risks when the biosolids are applied to agriculture. This study evaluated the impact of mesophilic anaerobic digestion on the fate of MPs in WWTP sludge. For this, two laboratory-scale anaerobic digesters were operated in parallel, consisting of a continuous stirred tank reactor (CSTR) and a membrane bioreactor (AnMBR) equipped with an ultrafiltration membrane to decouple the hydraulic and sludge retention times.
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