Search results for "Aerobic"
showing 10 items of 760 documents
Use of rumen microorganisms to boost the anaerobic biodegradability of microalgae
2017
[EN] A laboratory bioreactor using rumen microorganisms to treat Scenedesmus spp. biomass was operated for 190 days. At first the bioreactor operated as a Rumen-like Fermenter (RF) with a Sludge Retention Time (SRT) of 7 days. The RF was subsequently transformed into an anaerobic digestion system including two configurations: continuously-stirred tank reactor and anaerobic membrane bioreactor in which different SRT values of up to 100 days were assessed. Methane production peaked at 214 mL CH4 g−1 CODIn with a SRT of 100 days. COD removal and BDP peaked at above 70% and 60%, respectively, at the highest SRT, with no pre-treatment prior to microalgae digestion. The waste sludge product…
Anaerobic treatment of urban wastewater in membrane bioreactors: evaluation of seasonal temperature variations
2014
The objective of this study was to evaluate the effect of seasonal temperature variations on the anaerobic treatment of urban wastewater in membrane bioreactors (MBRs). To this aim, sludge production, energy recovery potential, chemical oxygen demand (COD) removal and membrane permeability were evaluated in a submerged anaerobic MBR fitted with industrial-scale membrane units. The plant was operated for 172 days, between summer and winter seasons. Sludge production increased and energy recovery potential decreased when temperature decreased. COD removal and membrane permeability remained nearby stable throughout the whole experimental period.
Mathematical Modelling of In-sewer Processes as a Tool for Sewer System Design
2018
The objective of this paper is to evaluate the potential impact of in-sewer processes (COD components transformation and hydrogen sulphide production) on the design of sewer systems. The tool used for such analysis is a mathematical model derived from the WATS model (Wastewater Aerobic/anaerobic Transformation in Sewers) able to describe the processes occurring in the sewer system both under aerobic and anaerobic conditions. The model is applied to three synthetic catchments with, respectively, 10,000, 50,000 and 250,000 inhabitants connected to gravity sewer systems different in terms of type (separate or combined), slope, length, travel time, wastewater temperature. The simulation results…
Biomethane Production from Anaerobic Co-Digestion of Selected Organic Fraction of Municipal Solid Waste (OFMSW) with Sewage Sludge: Effect of the Ino…
2021
The aim of this study was to evaluate the effect of the inoculum to substrate ratio (ISR) and the mixture ratio between organic fraction of municipal solid waste (OFMSW) and sewage sludge (SS) on the methane production potential achievable from anaerobic co-digestion (AcoD). Biochemical Methane Potential (BMP) assays at mesophilic temperature were used to determine the best AcoD configuration for maximizing methane yield and production rate, as well as to address possible synergistic effects. The maximum methane yield was observed at ISR of 1 and 60% OFMSW: 40% SS as co-digestion mixture, whereas the highest methane production rate was achieved at ISR of 2 with the same mixture ratio (207 m…
Effect of temperature and organic nutrients on the biodegradation of linear alkylbenzene sulfonate (LAS) during the composting of anaerobically diges…
2004
Limits on the application of biosolids (anaerobically processed sludges from wastewater treatment plants) as fertilizers for the amendment of soil are becoming greater because of the accumulation of recalcitrant substances, making necessary the use of techniques that bring the concentration of xenobiotics to lower concentrations than those permitted. In general, the biosolids composting process is sufficient to reduce the usual concentration of linear alkylbenzene sulfonates (LAS) to low levels. In this work, an assessment is made on the effect of temperature in the capacity of enriched bacterial populations to biodegrade LAS, together with the influence that the available nutrients may hav…
Benefits of a home-based physical exercise program in elderly subjects with type 2 diabetes mellitus
2011
Abstract Objective To analyze the effects of a home-based physical exercise program on quality of life, metabolic control, and anthropometric and biochemical parameters in people over 60 years of age with type 2 diabetes mellitus. Methods Eighty-four Spanish patients aged over 60 years were finally randomized to participate in a home-based, combined physical exercise program (aerobic and anaerobic exercises) or to receive conventional treatment for diabetes. At 6 months, effects on quality of life (EuroQoL questionnaire), HbA1c, fasting glucose, hypoglycemic events, weight, BMI, waist circumference, blood pressure, and biochemical parameters were assessed. Results Mean age of study particip…
Effect of training with Supejump® on bone metabolism in women
2021
Physical exercise is recommended to decrease bone loss in elderly women. Supejump® is a new workout activity performed on a modified elastic mini trampoline that mixes aerobic and anaerobic exercises. The aim of the study was to investigate the long-term effects of training with Supejump® on bone metabolism in women. Twelve women were involved in the study. They performed Supejump®, three times a week, each session lasting 60 mins for a total of 20-weeks. Blood samples were collected at baseline and at the end of the 20-weeks of training. The biomarkers of bone resorption (c-terminal telopeptide region of collagen type 1 (β-CTX)), bone formation (osteocalcin), and calcitonin, parathyroid ho…
Design methodology for submerged anaerobic membrane bioreactors (AnMBR): A case study
2015
[EN] The main objective of this study is to propose guidelines for designing submerged anaerobic MBR (AnMBR) technology for municipal wastewater treatment. The design methodology was devised on the basis of simulation and experimental results from an AnMBR plant featuring industrial-scale hollow-fibre membranes. The proposed methodology aims to minimise both capital expenditure and operating expenses, and the key parameters considered were: hydraulic retention time, solids retention time, mixed liquor suspended solids concentration in the membrane tank, 20 C-standardised critical flux, specificgas demand per square metre of membrane area, and flow of sludge being recycled from the membrane …
Mineralization of bone-related SaOS-2 cells under physiological hypoxic conditions
2015
Inorganic polyphosphate (polyP) is a physiological energy-rich polymer with multiple phosphoric anhydride bonds. In cells such as bone-forming osteoblasts, glycolysis is the main pathway generating metabolic energy in the form of ATP. In the present study, we show that, under hypoxic culture conditions, the growth/viability of osteoblast-like SaOS-2 cells is not impaired. The addition of polyP to those cells, administered as amorphous calcium polyP nanoparticles (aCa-polyP-NP; approximate size 100 nm), significantly increased the proliferation of the cells. In the presence of polyP, the cells produce significant levels of lactate, the end product of anaerobic glycolysis. Under those conditi…
Calibration and validation of activated sludge model No.2d for Spanish municipal wastewater.
2002
Activated Sludge Model No. 2d (ASM2d) was validated with data obtained from pilot scale plant treating municipal wastewater from the city of Valencia (Spain). First of all, ASM2d was calibrated using experimental data from anaerobic, anoxic and aerobic batches. A set of kinetic and stoichiometric parameters resulted from these assays. Differences between the values obtained and default values proposed in ASM2d can be explained by the presence of glycogen accumulating organisms (GAOs). The calibrated model was then used to simulate results from a pilot plant. Simulation using the set of parameters obtained accurately reproduces experimental results. This paper also presents a detailed proced…