Search results for " FOULING"
showing 10 items of 79 documents
Integrated fixed-film activated sludge membrane bioreactors versus membrane bioreactors for nutrient removal: A comprehensive comparison
2018
Abstract This research elucidates the pollutants (nutrients and carbon) removal performance and nitrous oxide (N2O) emissions of two pilot plants. Specifically, a University of Cape Town (UCT) Membrane Bioreactor (MBR) plant and an Integrated Fixed Film Activated Sludge (IFAS)-UCT-MBR plant were investigated. The plants were fed with real wastewater augmented with acetate and glycerol in order to control the influent carbon nitrogen ratio (C/N). The short-term effect of the inlet C/N ratio variation (C/N = 5 mgCOD/mgN and C/N = 10 mgCOD/mgN) on the behaviour of both plants was investigated. The results showed that the IFAS-UCT-MBR configuration provided the best performance in terms of poll…
Biofouling management in anaerobic membrane bioreactors
2020
Abstract This chapter is aimed at providing an insight on the main issues around the membrane fouling in anaerobic membrane bioreactors (AnMBRs). The analysis presented here shows that membrane fouling in AnMBRs is attributed to three major factors: membrane features, operating conditions, and wastewater characteristics. Several ad-hoc strategies have been implemented in literature to mitigate membrane fouling in AnMBRs, such as gas sparging, media addition, chemical cleaning, and membrane rotation/vibration. Among them, gas sparging is considered the most expensive strategy due to the high power requirement of the gas blower (up to 1.345 kWh m− 3). An accurate experimental and modeling ana…
Suspended and attached biomass in an mbr system treating high strength wastewater Loads
2012
abstract
PERFORMANCE OF A MBR PILOT PLANT SUBJECT TO A GRADUAL SALINITY INCREASE: ANALYSIS OF BIOKINETIC AND FOULING BEHAVIOR
2013
Membrane bioreactors (MBRs) have been widely used for the treatment of various wastewater, including municipal, industrial, landfill leachate (Wintgens et al., 2005). Such systems generally provide decisive advantages compared to conventional activated sludge (CAS) processes: in particular, they feature high quality effluent, small footprint and low sludge production rates (Stephenson et al., 2000). In recent years MBRs have also been used for the treatment of specific saline water, such as wastewater produced from shipboard activities, aquaculture wastewater or wastewater deriving by sediment washing treatment, as an example. However, when subject to salinity, a modification of biomass cha…
A comprehensive integrated membrane bioreactor model for greenhouse gas emissions
2018
Abstract A comprehensive integrated membrane bioreactor (MBR) model for wastewater treatment is here proposed. The model quantifies the main biological and physical processes. The model describes the biological removal of organic matter, nitrogen and phosphorus including greenhouse gases (carbon dioxide, CO 2 and nitrous oxide, N 2 O). The model takes into account the following main innovative aspects jointly: i. Two-step nitrification process; ii. N 2 O formation due to ammonia-oxidizing bacteria as a product of the hydroxylamine oxidation (NH 2 OH) and of the nitrite (NO 2 − ) reduction; iii. Soluble microbial product (SMP) formation/degradation due to microbial growth and endogenous resp…
Membrane bioreactors for treatment of saline wastewater contaminated by hydrocarbons (diesel fuel): An experimental pilot plant case study
2016
Abstract The paper reports the main results of an experimental campaign performed on a membrane bioreactor pilot plant designed to treat synthetic shipboard slops. The experimental campaign was divided into two phases: salinity acclimation up to 20 g NaCl L −1 (Phase I) and hydrocarbon (diesel fuel) dosing (Phase II). The observed results show that the carbon removal was not severely affected by the wastewater features. Conversely, respirometric tests showed that nitrification was strongly affected by the salinity (33% of nitrification efficiency at 20 g NaCl L −1 – Phase I) as a result of the salinity in the autotrophic biomass. Moreover, the sludge viscosity increased during Phase II due …
Performance of a MBR pilot plant treating high strength wastewater subject to salinity increase: Analysis of biomass activity and fouling behaviour
2013
Membrane bioreactors produce high quality effluents that could be suitable for reuse. However, when treating high strength wastewater subject to a salinity increase, a modification of biomass characteristics may occur. This circumstance is of importance, since it can have a significant impact in terms of biokinetic as well as fouling behaviour. The aim of the study was to evaluate the performance of a pilot plant MBR, in terms of biomass activity and membrane fouling, fed with high strength synthetic wastewater, when subject to a salinity increase. With normal salinity, the pilot plant showed high removal efficiencies and high biomass respiratory activity. On the other hand, the salinity in…
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…
Treatment of Oily Wastewater with Membrane Bioreactor Systems
2017
The aim of the present work was to investigate the behavior of a membrane bioreactor (MBR) system for the treatment of oily wastewater. A bench scale MBR was fed with synthetic wastewater containing diesel fuel. Organic carbon, hydrocarbon and ammonium removal, kinetic constants, extracellular polymeric substances production, and membrane fouling rates were monitored. The MBR plant was operated for more than 200 days, and the results highlighted good carbon removal and nitrification, suggesting a sort of biomass adaptation to hydrocarbons. Membrane fouling analysis showed an increase in total resistance, likely due to hydrocarbons, which caused an irreversible fouling (pore blocking) mainly…
The influence of solid retention time on IFAS-MBR systems: analysis of system behavior.
2018
A University of Cape Town Integrated Fixed-Film Activated Sludge Membrane Bioreactor (UCT-IFAS-MBR) pilot plant was operated at different values of the sludge retention time (SRT). Three SRTs were investigated at different durations: indefinitely, 30 and 15 days. The organic carbon, nitrogen and phosphorus removal, kinetic/stoichiometric parameters, membrane fouling tendency and sludge filtration properties were assessed. The findings showed that by decreasing the SRT, the pilot plant could maintain excellent carbon removal efficiencies throughout the experiments. In contrast, the biological carbon removal showed a slight nitrification and was slightly affected by the decrease of the SRT, s…