Search results for "sanita"
showing 10 items of 855 documents
The fouling phenomenon in membrane bioreactors: assessment of different strategies for energy saving
2012
Membrane fouling represents one of the major limiting issue for membrane bioreactor (MBR) in the wastewater treatment field. Membrane fouling and high aeration requirement (for inducing shear stress to limit fouling) in MBR systems make the operation of such systems economically demanding due to high energetic costs. Despite several studies on MBR fouling have been performed a comprehensive knowledge on how to reduce membrane fouling and consequently energy saving is still lacking and controversial. The aim of this study is to gain insights on the optimization of the operating conditions in an MBR system. In particular, the influence of the aeration intensity and the durations of filtration…
Uncertainty propagation throughout an integrated water-quality model
2010
In integrated urban drainage water quality models, due to the fact that integrated approaches are basically a cascade of sub-models (simulating sewer system, wastewater treatment plant and receiving water body), uncertainty produced in one sub-model propagates to the following ones depending on the model structure, the estimation of parameters and the availability and uncertainty of measurements in the different parts of the system. Uncertainty basically propagates throughout a chain of models in which simulation output from upstream models is transferred to the downstream ones as input. The overall uncertainty can differ from the simple sum of uncertainties generated in each sub-model, dep…
Biological nutrient removal in a UCT-MBR pilot
2010
In the last years, there has been an increasing awareness about the environment pollution protection. As a consequence, the Environmental Regulation has increased the emission limits imposing, for instance, lower concentrations at the wastewater treatment plant (WWTP) outlets. As a consequence of this fact, several WWTPs are not able to respect the emission limits and need to be upgraded. In view of such needs new technology are emerging and new WWTP solution schemes are being realized. With respects to the nutrient removal enhancing, a possible solution can be the UCT-MBR which couples the University of Cape Town scheme with a Membrane Bioreactor. In the light of such considerations, the s…
The management of sewage sludge: technologies, critical issue and perspectives
2022
The management of sludge produced by urban wastewater treatment plants has long been a problem for plant managers. This is due both to the growing costs for their disposal, and to the possible consequences that incorrect management may have on the performance of the wastewater treatment plant and on the environment. Further difficulties arose following the evolution of the European and national legislations, which regulates the management of sludge and its possible agronomic uses that introduced further checks and restrictions for this use. Several studies have been underway since last decades to reduce the extent of the problem. These focus on alternative objectives being aimed on the one …
Trattamento di reflui industriali con sistemi biologici a biomassa aerobica granulare: analisi delle performance di processo e della stabilità del fa…
Greenhouse Gas Emissions from Membrane Bioreactors
2017
Nowadays, it is widely accepted that wastewater treatment plants (WWTPs) are significant sources of greenhouse gas (GHG) emission, contributing to the anthropogenic sources. Among the GHG emitted from WWTPs, nitrous oxide (N2O) has been identified of having the major interest/concern, since its high global warming potential (GWP), is 298 times higher than that of CO2 and also to its capability to react with stratospheric ozone causing the layer depletion. Up to now, most of the experimental investigations have been carried out on conventional activated sludge (CAS) processes. The knowledge of N2O emission from advanced technologies such membrane bioreactors (MBRs) is still very limited. The…
Capitolo 12 - Interventi per il trattamento delle acque di pioggia
2014
Il Foaming negli impianti MBR
2013
New applications in integrated fixed film activated sludge-membrane bioreactor (IFAS-MBR) systems
2020
Abstract This chapter provides an overview on the development and application of integrated fixed film activated sludge-membrane bioreactor (IFAS-MBR) systems. IFAS-MBRs represent a novel configuration for advanced wastewater treatment, and only a few studies are available in literature. With this aim, the results of some studies on IFAS-MBR systems already published are discussed and compared in this chapter. Literature shows that the influent carbon to nitrogen ratio (C/N) strongly affects the biological process in IFAS-MBR. The organic matter removal efficiency (removed biologically) decreases from 60% to 23.5% with the decrease of influent C/N from 10 to 2 mgCOD mgTN− 1. Nitrogen remova…
Greenhouse gases from membrane bioreactors: a pilot plant case study
2015
In this study the N2O emitted from the aerobic and anoxic tank of a Sequential Batch (SB) Membrane Bioreactor (MBR) pilot plant has been investigated. The SB-MBR pilot plant was fed with a mixture of synthetic and real wastewater. The influence of salinity on N2O concentration was analyzed by gradually increasing the salinity by addition of salt to concentrations ranging from 0 to 10 gNaCl L-1. The results demonstrated that the N2O concentration of the gaseous samples was strongly influenced by the salinity in the range of 0.25 ppm to 3.4 ppm salinity. This result was explained by lower autotrophic kinetics due to the biomass lysis. Dissolved oxygen concentration and salinity were found to …