Search results for "spirometri"
showing 10 items of 23 documents
Quantification of kinetic parameters for heterotrophic bacteria via respirometry in a hybrid reactor
2010
Over the last decade new technologies are emerging even more for wastewater treatment. Among the new technologies, a recent possible solution regards Moving Bed Biofilm Reactors (MBBRs) that represent an effective alternative to conventional processes. More specifically such systems consist in the introduction of plastic elements inside the aerobic reactor as carrier material for the growth of attached biomass. Recently, one of the mostly used alternatives is to couple the Moving Bed Biofilm Reactor (MBBR) process with the conventional activated sludge process, and the resulting process is usually called HMBBR (Hybrid MBBR). In the MBBR process the biofilm grows attached on small plastic el…
Respirometry for the Characterization of Heterotrophic Biomass Activity: Application to a MBR Pilot Plant Operated with Two Different Start-Up Strate…
2016
A membrane bioreactor (MBR) pilot plant was operated in two subsequent experimental periods (namely, Periods I and II) with different start-up and sludge withdrawal strategies to study its peculiar biokinetic behavior by using respirometric techniques. Two extreme operational conditions were chosen to investigate the different biomass activity under dynamic or pseudostationary conditions during and after the start-up phases. Particularly, the MBR pilot plant was operated with the same volumetric loading rate (VLR) and permeate flux but differently managed during the start-up phase. In Period I, the MBR pilot plant was started up without sludge inoculum and operated without sludge withdrawal…
Telomere Length in Circulating Leukocytes is Associated with Lung Function and Disease
2014
Several clinical studies suggest the involvement of premature ageing processes in chronic obstructive pulmonary disease (COPD). Using an epidemiological approach, we studied whether accelerated ageing indicated by telomere length, a marker of biological age, is associated with COPD and asthma, and whether intrinsic age-related processes contribute to the interindividual variability of lung function. Our meta-analysis of 14 studies included 934 COPD cases with 15 846 controls defined according to the Global Lungs Initiative (GLI) criteria (or 1189 COPD cases according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria), 2834 asthma cases with 28 195 controls, and s…
Ekspiratorisk flow avgrensingar under fysisk belastning hos ungdommar med astma : Før og etter 10 vekers intervensjon
2019
Masteroppgave folkehelsevitenskap ME516 - Universitetet i Agder 2019 Background:Asthma is a chronic inflammatory disorder associated with variable airflo w obstruction and bronchial hyperresponsivness. Asthma may interfere with the ability of childre n and adolescents to participatein physical activity, as well ascreatebarriers towards involvement. Physical activity is an important stimulus for asthma symptoms. Exercise-induced bronchoconstriction is traditionally used when physical activity is the cause of asthma symptoms, but this is measured after exercise. There is little knowledge about flow limitat io n during exercise. Aim:The purpose of this study is to investigate expiratory flow l…
Sequential batch membrane bio-reactor for wastewater treatment: The effect of increased salinity
2016
In this work, a sequential batch membrane bioreactor pilot plant is investigated to analyze the effect of a gradual increase in salinity on carbon and nutrient removal, membrane fouling and biomass kinetic parameters. The salinity was increased by 2 g NaCl L-1 per week up to 10 g NaCl L-1. The total COD removal efficiency was quite high (93%) throughout the experiment. A gradual biomass acclimation to the salinity level was observed during the experiment, highlighting the good recovery capabilities of the system. Nitrification was also influenced by the increase in salinity, with a slight decrease in nitrification efficiency (the lowest value was obtained at 10 g NaCl L-1 due to lower nitri…
Near-normal aerobic capacity in long-term survivors after lung transplantation
2021
The clinical course of lung transplantation (LT) is diverse: some patients present chronic lung allograft dysfunction (CLAD) and progressive decline in pulmonary function, but others maintain normal spirometric values and active lives. Objectives The aim of this study was to elucidate whether long-term LT survivors with normal spirometry achieve normal exercise capacity, and to identify predictive factors of exercise capacity. Methods This was a cross-sectional multicentre study, where bilateral LT recipients who survived at least 10 years after LT, with normal spirometry, no diagnosis of CLAD and modified Medical Research Council dyspnoea degree ≤2 underwent cardiopulmonary exercise testin…
TREATMENT OF LANDFILL LEACHATE IN SBR SYSTEMS: ANALYSIS OF BIOMASS ACTIVITY BY MEANS OF RESPIROMETRIC TECHNIQUES
2013
In the last decades landfilling has been the main method of municipal solid waste (MSW) disposal in many countries. MSW landfills are usually considered as a large biological reactor where the MSWs undergo anaerobic digestion producing gas and liquid emissions. Aged, or mature leachate, which is produced by older landfills, can be very refractory; for this reason mature leachate is difficult to treat alone, but it can be co-treated with sewage or domestic wastewater. The aim of the study was to investigate the feasibility of co-treatment of landfill leachate and synthetic wastewater in different percentages, in terms of process performance and biomass activity, by means of respirometric tec…
Characterization of wastewater and biomass activity in a membrane bioreactor using respirometric techniques
2010
Over the last two decades, Membrane Bioreactors (MBRs) emerged even more for wastewater treatment, ensuring high removal efficiencies as well as very small footprint required. Indeed, in this kind of process, a modification in biomass activity and viability can exist compared to that of a conventional activated sludge (CAS) process. In this context, respirometric analysis represents a reliable tool in order to evaluate the actual biomass kinetic parameters, to insert in mathematical models in the design phase, as well as to monitor the biomass viability, especially when these processes are operated with high sludge retention time (SRT) values. The paper presents some results of respirometri…
Respirometry for the assessment of biomass activity in Membrane Bioreactors
2017
The aim of the study was to use respirometric techniques for the characterization of biomass biokinetic behaviour in several MBR pilot plants characterized by different configurations, different operational conditions and fed with wastewater of different features (domestic/industrial). Four different MBR pilot plants were investigated: i) a sequencing batch MBR (SB-MBR) subjected to a gradual salinity increase; ii) a pre-denitrification MBR system for the treatment of saline wastewater contaminated by hydrocarbons; iii) a University of Cape Town MBR system (UCT-MBR) for the treatment of domestic wastewater subjected to a carbon-to-nitrogen (C/N) ratio variation; iiii) a UCT-IFAS-MBR for the…
Sequential Batch Membrane BioReactor treating saline wastewater
2015
A sequential batch membrane bioreactor treating high strength salinity wastewater has been investigated. The salt effects on carbon and nutrient removal, fouling behaviour as well as biomass kinetics have been analysed. Salinity was increased at step of 2 g NaCl L-1 per week. The total COD removal efficiency was high (93%) along the entire experimental campaign. However, the biological contribution on the COD removal efficiency was reduced with the increase of salinity. The lowest nitrification removal efficiency (63%) was obtained at 10 g NaCl L-1 salinity due to the lower nitrifier activity. Regarding membrane fouling, the irreversible cake deposition was the predominant fouling mechanism…