Search results for "Process (engineering)"
showing 10 items of 931 documents
A Friendly-Biological Reactor SIMulator (BioReSIM) for studying biological processes in wastewater treatment processes
2014
Biological processes for wastewater treatments are inherently dynamic systems because of the large variations in the influent wastewater flow rate, concentration composition and the adaptive behavior of the involved microorganisms. Moreover, the sludge retention time (SRT) is a critical factor to understand the bioreactor performances when changes in the influent or in the operation conditions take place. Since SRT are usually in the range of 10-30 days, the performance of biological reactors needs a long time to be monitored in a regular laboratory demonstration, limiting the knowledge that can be obtained in the experimental lab practice. In order to overcome this lack, mathematical model…
Prediction models to analyse the performance of a commercial-scale membrane distillation unit for desalting brines from RO plants
2018
Abstract Desalting brines from Reverse Osmosis (RO) plants is one of the most promising applications of Membrane Distillation (MD) systems. The development of accurate models to predict MD system performances plays a significant role in the design of this kind of industrial applications. In this paper, a commercial-scale Permeate-Gap Membrane Distillation (PGMD) module was modelled by means of two different approaches: Response Surface Methodology (RSM) and Artificial Neural Networks (ANN). Condenser inlet temperature, evaporator inlet temperature, feed flow rate and feed water salt concentration were selected as inputs of the model, while permeate flux and Specific Thermal Energy Consumpti…
On the Effectiveness of SPIF Process to Re-Form End-of-Life Components as Compared to Conventional Forming Approach
2021
Manufacturing processes have a significant impact on global energy consumptions. The recovery of materials and functions for the implementation of the Circular Economy principle needs to be focused on either, by utilizing new techniques or the rethinking of old processes to rework End-of-life (EoL) components. Previous researches have shown Single Point Incremental Forming (SPIF) process as a good alternate for sheet metal EoL components reuse by their reshaping. In this article, the authors aim to study the effectiveness of the SIPF processes by comparing its reshaping performance with other, more conventional forming processes. An initial deep drawing process was performed to imitate alum…
Extraction of bioactive compounds and essential oils from mediterranean herbs by conventional and green innovative techniques: A review
2018
International audience; Market interest in aromatic plants from the Mediterranean is continuously growing mainly due to their medicinal and bioactive compounds (BACs) with other valuable constituents from essential oils (EOs). From ancient times, these plants have been important condiments for traditional Mediterranean cuisine and remedies in folk medicine. Nowadays, they are considered as important factors for food quality and safety, due to prevention of various deteriorative factors like oxidations and microbial spoilage. EOs have different therapeutic benefits (e.g. antioxidant, anti-inflammatory, antimicrobial, and antifungal), while BACs mostly affect nutritive, chemical, microbiologi…
Minimizing membrane bioreactor environmental footprint by multiple objective optimization.
2020
This paper presents a modelling study aimed at minimizing the environmental foot print of a membrane bioreactor (MBR) for wastewater treatment. Specifically, an integrated model for MBR was employed in view of the management optimization of an MBR biological nutrient removal (BNR) pilot plant in terms of operational costs and direct greenhouse gases emissions. The influence of the operational parameters (OPs) on performance indicators (PIs) was investigated by adopting the Extended-FAST sensitivity analysis method. Further, a multi-objective analysis was performed by applying the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The results show-up that the sludge …
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…
Photocatalytic membrane reactors for water treatment
2015
Abstract Heterogeneous photocatalysis is an advanced oxidation process largely studied in the field of environment recovery by the total degradation of organic and inorganic pollutants and for synthesis. In this chapter, the basic principles of photocatalysis are discussed with the advantages related to its coupling with a membrane separation in photocatalytic membrane reactors (PMRs). The types of membranes most widely used and their criteria of selection are briefly discussed. PMRs’ classification based on their configuration and on the type of membrane operation is also discussed, evidencing as their appropriate choice is a key step in view of large-scale implementation. Finally, some ca…
Influence of the methodology of inoculation in the performance of air-breathing microbial fuel cells
2017
In this work, four air-breathing microbial fuel cells (AB-MFC) were operated for 1 month in order to determine if the methodology of inoculation affects the steady-state performance of this type of MFCs. For this purpose, anaerobic and aerobic sludge were fed to two identical AB-MFCs without any external carbon source into a tight sealed environment during the first three days of start-up. For comparison purposes, other two AB-MFCs were operated mixing the initial sludge and an amount of sodium acetate as substrate. Results point out that the inoculation procedure does not affect the steady-state treatment capacity of the cells but it affects very seriously the production of electricity. On…
Using Matlab's wavelet toolbox to compare electric signals outputted by microbial fuel cells
2019
Motivation: microbial fuel cells (MFC) represents a wastewater treatment technology with the potential for a relevant electric energy generation. The monitoring of the electric current outputted generates time series of data. It was generated two time series using an experimental setup with a low-cost dual chamber microbial fuel cell treating cassava wastewater and, also, it was used the electric current data from a previously described experiment with this same setup treating cheese whey. All of this, innovatively, according our best knowledge, was studied using power spectral density, multifractal and wavelet coherence analysis. Results are promising and indeed point out this approach as …
On the staking of miniaturized air-breathing microbial fuel cells
2018
Abstract This work focuses on the scale-up of the MFCs by miniaturization and multiplication strategy. Performances of five stacks containing 1, 2, 5, 8 and 16 MFCs were compared. Each stack was evaluated under individual, parallel and series electrical connection as well as for cascade or individual hydraulic connection. Cascade feeding mode with a tank per stack favours the COD removal when the number of MFCs in the stack increases. However, despite operating without COD limitations, the energy production was disadvantaged. By changing the feeding system of a tank per stack into an individual tank per MFC, the performance of the whole stack enhances considerably. Stacking in series can in…