Search results for " Ingegneri"
showing 10 items of 809 documents
BioMAc 2013. I bioreattori a membrana per la depurazione delle acque reflue
2013
Foaming in membrane bioreactor: identification of the causes
2012
The biological foaming was related to the metabolism of certain microorganisms that synthesize and excrete hydrophobic compounds. Recently, by the attention of many researchers the biological foaming in the MBR has attracted, because MBR foam has been also observed in the absence of foam-forming microorganisms, contrarily to conventional activated sludge systems. In this paper the authors investigate the role of EPS and filamentous bacteria analyzing different samples from different MBR pilot plants. In particular, in order to define the macroscopic features and the role of EPS and filamentous bacteria a modified Scum Index (MSI) test was applied. Further a multiple classification of SI was…
Criteri di progettazione dei bioreattori a membrana
2013
Evaluation of biomass activity in membrane bioreactors by means of respirometric techniques
2016
The paper reports the main results of a respirometric experimental survey carried out on several membrane bioreactor pilot plants, characterized by different pilot plant layouts as well as operational conditions. The main aim was to assess the influence of specific conditions on biokinetic/stoichiometric parameters. In particular, the respirometric tests were specifically aimed at investigating the activity of both heterotrophic and autotrophic bacterial species. The achieved results showed that the plant configuration and the features of the feeding wastewater and operational conditions determine significant variation of the kinetic coefficients. The respirometric analysis was confirmed to…
Analisi sperimentale e modellistica di formazione del fouling delle membrane nei sistemi MBR
2012
Greenhouse gas emissions from membrane bioreactors: analysis of a two-year survey on MBRs
2017
The study aims at evaluating the nitrous oxide (N2O) emission from membrane bioreactors (MBRs) for wastewater treatment. With this regards two-years of experimental activities were performed. More specifically, the study investigates the N2O emissions considering multiple influential factors: i. configurations (i.e., sequential batch- SB-MBR; pre-denitrification - DN-MBR; University Cape Town, UCT-MBR and UCT moving bed biofilm reactor, UCT-MB-MBR); ii. wastewater composition (municipal or industrial); iii. Plant operational conditions (i.e., sludge retention time, SRT, carbon-to-nitrogen ratio, C/N, hydraulic retention time, HRT); iv. and membrane modules. Among the overall analysed config…
Removal of carbon and nutrients from wastewater in a moving bed membrane biofilm reactor: the influence of the sludge retention time
2016
A University of Cape Town (UCT) pilot plant combining both membrane bioreactor (MBR) and moving bed biofilm reactor (MBBR) technology was monitored. Three experimental Phases were carried out by varying the mixed liquor sludge retention time (SRT) (indefinite, 30 and 15 days, respectively). The system performance has been investigated during experiments in terms of: organic carbon, nitrogen and phosphorus removal, biokinetic/stoichiometric constants, membrane fouling tendency and sludge dewaterability. The observed results showed that by decreasing the SRT the UCT pilot plant was able to maintain very high total COD removal efficiencies, whilst the biological COD removal efficiency showed a…
High salinity slops treatment through a biofilm-MBR inoculated with halophilic bacteria
2010
Oily wastewater generated, in amounts of millions of tons per year, by ships mainly in engine-rooms (bilge waters) and by washing oil tanks (slops) create a major disposal problem throughout the world because of the persistence and accumulation of xenobiotic compounds in the environment. The high salinity levels (up to 25.000 p.p.m.) and the pollutants concentration limit the chances of discharge into the sewer systems and address the disposal to the sea. This situation severely lowers the discharge limits for most of the “sensible” parameters, such both COD and hydrocarbons. Slops are usually treated by ASP with pretreatment of oil/water separation. There are limited investigations on the …
Improving Of The Productivity And The Quality Of A Manufacturing Robotized Cell For Mig/Mag Welding
2007
During the last years, globalization and the necessity to reduce production costs have pushed industry to employ more and more manufacturing robotized cells. This trend has been assimilated by arc welding too. The use of robotic systems allows to increase the performance of productive systems by means of reduction in lead-time, reproducibility of processes and increase in quality. However, process automation needs pre-scheduling of manufacturing cell movements and also a setup of different welding parameters, such as power provided by the welding generator, arc length and robot speed, all of which allows to get a joint without defects. An online scheduling of robotic systems brings certainl…
Networking strategy for competitive advantage
2011
This paper explores the potential of networking strategy as a source of competitive advantage by integrating market- based and resource-based logics. It contributes to operations management literature by considering not just supply chain structures but also others kinds of network that can emerge from horizontal agreements (i.e. alliances, partnerships, joint ventures, etc.). The paper reviews the literature and develops propositions regarding how make/buy/make together decisions, governance mechanisms and network-base structures allow firms both to pursue operations performance objectives and obtain/create valuable resources. A case study supports the propositions and shows a practical app…