Search results for "WASTE"
showing 10 items of 2580 documents
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 …
Quantifying sensitivity and uncertainty analysis of a new mathematical model for the evaluation of greenhouse gas emissions from membrane bioreactors
2015
Abstract A new mathematical model able to quantify greenhouse gas (GHG) emissions in terms of carbon dioxide (CO 2 ) and nitrous oxide (N 2 O) for a Membrane Bioreactor (MBR) is presented. The proposed mathematical model is of the Activated Sludge Model (ASM) family and takes into account simultaneously both biological and physical processes (e.g., membrane fouling). An analysis of the key factors and sources of uncertainty influencing GHG emissions is also presented. Specifically, the standardized regression coefficient, the Extended-FAST and a Monte Carlo based method are employed for assessing model factors which influence three performance indicators: effluent quality index, operational…
Direct Measurement of Methane Emission Rates: Multiyear Application to a Municipal Landfill in Southern Italy
2012
Municipal Solid Waste (MSW) landfills have been identified as one of the most important sources of methane (CH4) emission. MSW contains a certain amount of biodegradable organic matter which undergoes anaerobic degradation resulting in the production of the landfill gas (LFG), which main component is tipically represented by CH4. In order to minimise its negative effects on the envi-ronment, LFG recovery is a suitable tool to control CH4 emissions from a landfill site and the measurement of CH4 emissions represents a good way to evaluate the effectiveness of LFG recover-ing system in reducing biogas emission to the atmosphere. However, up to now few measurements of landfill CH4 emissions ha…
Health Care Waste production: measures and estimates in Joint Hospitals “Civico e Benfratelli, Ascoli e Di Cristina”, Palermo, Italy.
2008
A monitoring work was carried out in October 2006 in one large health care facility located in Palermo. The monitoring consisted in weighing infectious waste containers filled in some Departments purposely chosen. As a second stage of the work a comparison was attempted between the results obtained from the waste production monitoring and the archive data recorded in the same time. A restricted list of purchased products out of the general one was extracted. Such list allows one to calculate approximately the mass of medical devices purchased and their composition. To these materials a reasonable change in humidity after use was attributed. It was possible in this deductive way to draw a pr…
Variance-based sensitivity analysis for wastewater treatment plant modelling
2014
Global sensitivity analysis (GSA) is a valuable tool to support the use of mathematical models that characterise technical or natural systems. In the field of wastewater modelling, most of the recent applications of GSA use either regression-based methods, which require close to linear relationships between the model outputs and model factors, or screening methods, which only yield qualitative results. However, due to the characteristics of membrane bioreactors (MBR) (non-linear kinetics, complexity, etc.) there is an interest to adequately quantify the effects of non-linearity and interactions. This can be achieved with variance-based sensitivity analysis methods. In this paper, the Extend…
Global sensitivity analysis in ASM applications: comparison of the SRC and Extended-FAST method for a UCT-MBR model
2011
In this study global sensitivity analysis is performed to identify influential as well as non-influential parameters in a model of a University Cape Town Membrane Bioreactor (UCT-MBR). In particular, the Standardised Regression Coefficients (SRC) and Extended-FAST sensitivity analysis methods are applied. The sensitivity of model variables towards parameter variation is analysed for CODTOT, SNH4, SNO3, SPO, and MLSS along five reactor compartments. Both methods indicate that the parameters identified as being influential differ from section to section due to the different processes involved. Moreover, the relevant influence of the membrane filtration parameters is detected in the first plan…
Materials recovery from WEEE: current situation in Sicily.
2012
The potential recovery of materials and energy in one year in Italy and in Sicily was estimated assuming that all WEEEs were gathered through the collection – treatment – disposal system implemented according to the rules in force. The embodied energy (EE) recovery associated to material recovery was also estimated, starting from standard values of EE and from yields declared for each component. Mass fractions composition for some categories of WEEE given by a facility in Catania agree with the national averages. Starting from data given by another facility - located in Siracusa - which processes all the five R categories (R1 to R5), potential mass and energy recovery was estimated for this…
Estimation of methane emission by a municipal landfill: the case of Palermo
2010
CH4 diffuse emissions from municipal solid waste landfills represent one of the most important anthropogenic source of greenhouse-gas. CH4 is produced by anaerobic biodegradation of organic matter in land-filled MSW and it constitutes the major component of landfill gas. Gas recovery is a suitable tool to effectively control CH4 emissions from landfill sites and the quantification of CH4 emissions represents a good tool to evaluate the effectiveness of biogas recovering system in reducing biogas emission. In particular, LFG emissions can be indirectly evaluated from mass balance equations between formation, recovery and oxidation of biogas in the landfill, as well as on a direct approach ba…
PLASTICS RECOVERY FROM MUNICIPAL WASTE: MAINSTREAMS AND BY-PRODUCTS IN A CASE STUDY IN NORTHERN ITALY.
2014
In the case study dealt with here, the factory treatments of dry Municipal Solid Waste are aimed primarily at materials recovery; restraining energy recovery to the hardly recyclable by-products. The main input consists of the so-called multipak from MSW source-sorted collection; plus packaging waste, paper and cardboard and other similar waste from curb-side collection. The principal fractions produced by the selection plant, own and operated by the Public Company in charge of MSW management, in the Year 2012 were 27 064 tonnes of plastics, 5 066 of paper, 3 014 of tin coated steel and 4 886 tonnes of extraneous fraction to dispose of. A minor – though valuable – product was aluminium. The…