Search results for "Membrane technology"
showing 10 items of 37 documents
A new strategy to maximize organic matter valorization in municipalities: combination of urban wastewater with kitchen food waste and its treatment w…
2017
[EN] The aim of this study was to evaluate the feasibility of treating the kitchen food waste (FW) jointly with urban wastewater (WW) in a wastewater treatment plant (WWTP) by anaerobic membrane technology (AnMBR). The experience was carried out in six different periods in an AnMBR pilot-plant for a total of 536 days, varying the SRT, HRT and the food waste penetration factor (PF) of food waste disposers. The results showed increased methane production of up to 190% at 70 days SRT, 24 hours HRT and 80% PF, compared with WW treatment only. FW COD and biodegradability were higher than in WW, so that the incorporation of FW into the treatment increases the organic load and the methane producti…
Effect of long residence time and high temperature over anaerobic biodegradation of Scenedesmus microalgae grown in wastewater
2018
[EN] Anaerobic digestion of indigenous Scenedesmus spp. microalgae was studied in continuous lab-scale anaerobic reactors at different temperatures (35 degrees C and 55 degrees C), and sludge retention time - SRT (50 and 70 days). Mesophilic digestion was performed in a continuous stirred-tank reactor (CSTR) and in an anaerobic membrane bioreactor (AnMBR). Mesophilic CSTR operated at 50 days SRT only achieved 11.9% of anaerobic biodegradability whereas in the AnMBR at 70 days SRT and 50 days HRT reached 39.5%, which is even higher than the biodegradability achieved in the thermophilic CSTR at 50 days SRT (30.4%). Microbial analysis revealed a high abundance of cellulose-degraders in both re…
Microbial community characterization during anaerobic digestion of Scenedesmus spp. under mesophilic and thermophilic conditions
2017
[EN] Microbial communities were thoroughly characterized in a mesophilic anaerobic membrane bioreactor (AnMBR) and a thermophilic continuous stirred tank reactor (CSTR), which were both treating recalcitrant microalgal biomass dominated by Scenedesmus. 16S rRNA amplicon sequencing analysis was performed when the AnMBR achieved 70% algal biodegradation and revealed high microbial diversity, probably due to the high solid retention time (SRT) of the AnMBR configuration. The bacterial community consisted of Chloroflexi (27.9%), WWE1 (19.0%) and Proteobacteria (15.4%) as the major phyla, followed by Spirochaetes (7.7%), Bacteroidetes (5.9%) and Firmicutes (3.6%). These phyla are known to exhibi…
Reverse osmosis and nanofiltration membranes for highly efficient PFASs removal: overview, challenges and future perspectives
2021
Today, it is extremely urgent to face the increasing shortage of clean and safe water resources, determined by the exponential growth of both world population and its consumerism, climate change and pollution. Water remediation from traditional chemicals and contaminants of emerging concerns (CECs) is supposed to be among the major methods to solve water scarcity issues. Reverse osmosis (RO) and nanofiltration (NF) membrane separation technologies have proven to be feasible, sustainable and highly effective methods for the removal of contaminants, comprising the extremely persistent and recalcitrant perfluoroalkyl substances (PFASs), which failed to be treated through the traditional water …
Pervaporation membrane reactors
2013
Pervaporation is a peculiar membrane separation process which is now considered for the integration with some types of reactions in new promising and interesting applications. Indeed, pervaporation membrane reactors are suitable to some specific utilizations also in sustainable chemistry, which is an area currently characterized by a growing interest. The fundamentals of this type of membrane reactors are presented and the advantages and the difficulties in many applications are discussed and reviewed with particular attention to the opportunities for future developments.
Supported liquid membrane extraction of aromatic aminophosphonates
2001
Abstract A fast and efficient supported liquid membrane (SLM) extraction system for the series of substituted aromatic aminophosphonates was elaborated. The mass transfer of solute was examined in terms of operator (pH and ionic strength of water phase, composition of membrane phase and the concentration of analyte) dependent parameters. Additionally, the influence of the aminophosphonates structure on the extraction efficiency was examined. From the results it can be concluded that the most effective conditions of membrane process are 10% (w/w) carrier concentration (Aliquat 336) in the liquid membrane, high pH of donor phase (pH=11) and moderate salt concentration (0.4 M NaCl) in the acce…
Energy saving with MSF-RO series desalination plants
2003
Two major techniques are commercially used in different parts of the world: distillation and membrane processes. The dominant distillation process is multi-stage flash (MSF), and the main membrane process is reverse osmosis (RO). Although cost factors vary by site, the total cost of producing potable water from seawater with the RO process is today usually less than thermal desalting processes and the economic advantages of RO vs. evaporation process, such as MSF, are responsible for the rapid increase in use of seawater RO. In many countries both RO and MSF processes are operating. Reduction in product water cost could be achieved when a hybrid MSF-RO system is used, instead of a parallel …
Energy saving in two-stage reverse osmosis systems coupled with ultrafiltration processes
2005
In this paper the optimization of the main design parameters is performed for a double-stage seawater reverse osmosis (SWRO) system coupled with an ultrafiltration process; the minimal energy consumption is the goal of the optimization process. The energetic benefits for the membrane process are calculated, deriving from the use of a hybrid two-stage/two-pass lay-out with ultrafiltration pre-treatment, which is a typically a low energy consumption process. Also the benefits on membranes’ efficiency and duration are assessed by examining the very low Silt Density Index (SDI) of the water exiting the ultrafiltration section. The analysed system includes a SWRO membrane in the high pressure st…
Electrospun nanofibers: role of nanofibers in water remediation and effect of experimental variables on their nano topography and application process…
2021
Water is the elixir of life and the most elementary need for the survival of human beings on planet Earth. With rapid industrialization, globalization and human exploitation, natural water resources are diminishing at a startling rate wherein availability of potable water has drastically decreased in recent times and hence membrane technology is a highly pursued area for water purification. The simple and cost-effective electrospinning technique has evolved to be a state-of-the-art method for developing nanofibers of tailored thickness and diameters by combining a broad range of starting materials. This comprehensive review emphasizes on the demonstration of electrospun nanofibers based on …
Methane recovery efficiency in a submerged anaerobic membrane bioreactor (SAnMBR) treating sulphate-rich urban wastewater: Evaluation of methane loss…
2012
The present paper presents a submerged anaerobic membrane bioreactor (SAnMBR) as a sustainable approach for urban wastewater treatment at 33 and 20 C, since greenhouse gas emissions are reduced and energy recovery is enhanced. Compared to other anaerobic systems, such as UASB reactors, the membrane technology allows the use of biogas-assisted mixing which enhances the methane stripping from the liquid phase bulk. The methane saturation index obtained for the whole period (1.00 ± 0.04) evidenced that the equilibrium condition was reached and the methane loss with the effluent was reduced. The methane recovery efficiency obtained at 20 C (53.6%) was slightly lower than at 33 C (57.4%) due to …