Francesca Macedonio

Water droplets as template for next-generation self-assembled poly-(etheretherketone) with cardo membranes.

Next generation PEEK-WC membranes have been fabricated by using an innovative self-assembly technique. Patterned architectures have been achieved via a solvent-reduced and water-assisted process, resulting in honeycomb packed geometry. The membranes exhibit monodisperse pores with size and shape comparable to those left by templating water droplets. Influencing factors for the formation of self-assembled poly-(etheretherketone) with Cardo [PEEK-WC] membranes have been evaluated, identifying the critical parameters for nucleation, growth, and propagation of the droplet-mobile arrays through the overall films. Structure-transport relationships have been discussed according to the results achieved from the implementation of membrane distillation processes, yielding indication about the suitability of self-assembled PEEK-WC films to work as interfaces in contactor operations.

Membrane crystallization for salts recovery from brine—an experimental and theoretical analysis

AbstractIntegration of innovative membrane processes such as membrane distillation (MD) and membrane crystallization (MCr) with conventional pressure-driven operations provide interesting gateways to recover water and minerals from brine at cost competitive with traditional techniques and with improved quality of the salts extracted. Membrane development is one of the most important factors for future progress and commercialization of MD and MCr, thus, in this study, the performance of different poly(vinylidene fluoride) membranes have been tested for water production from (1) NaCl solutions, (2) synthetic sea water, and (3) brine. The utilized membranes have also proved their stability in treatment of saturated solutions for the recovery of high-quality epsomite crystals. In desalination, MD and MCr provide, besides water recovery factors above 90%, the possibility to recover minerals from brine that can partly contribute to the existing mineral extraction industry. This study aims also to give an outloo...

Application of Membrane Crystallization for Minerals' Recovery from Produced Water.

Produced water represents the largest wastewater stream from oil and gas production. Generally, its high salinity level restricts the treatment options. Membrane crystallization (MCr) is an emerging membrane process with the capability to extract simultaneously fresh water and valuable components from various streams. In the current study, the potential of MCr for produced water treatment and salt recovery was demonstrated. The experiments were carried out in lab scale and semi-pilot scale. The effect of thermal and hydrodynamic conditions on process performance and crystal characteristics were explored. Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analyses confirmed that the recovered crystals are sodium chloride with very high purity (>99.9%), also indicated by the cubic structure observed by microscopy and SEM (scanning electron microscopy) analysis. It was demonstrated experimentally that at recovery factor of 37%, 16.4 kg NaCl per cubic meter of produced water can be recovered. Anti-scaling surface morphological features of membranes were also identified. In general, the study provides a new perspective of isolation of valuable constituents from produced water that, otherwise, is considered as a nuisance.

Membrane operations for produced water treatment

AbstractGrowing energy demand associated with improved living standards and rising population has increased the consumption of petroleum-based energy sources. To bridge the gap between demand and supply of petroleum-based energy resources, enhanced oil recovery and exploration of new nonconventional resources including shale gas, coal bed methane gas, and tight gas have gained popularity. These new techniques, however, use relatively fresh water and produce huge volumes of highly contaminated produced water. From compositional and potential treatment options, bilge water can also be included in the category of produced water. This work provides an overview of the investigations carried out for the removal of oil and greases using a membrane bioreactor and various other membrane operations. An analysis of a current and future scenario of produced water generated through conventional and nonconventional sources of energy and the perspective of produced water treatment in Saudi Arabia are also given. Finally...

Membrane-based desalination : an integrated approach (MEDINA)

Reverse osmosis is the dominant technology in water desalination. However, some critical issues remain open: improvement of water quality, enhancement of the recovery factor, reduction of the unit water cost, minimizing the brine disposal impact. This book aims to solve these problems with an innovative approach based on the integration of different membrane operations in pre-treatment and post-treatment stages. Membrane-Based Desalination: An Integrated Approach (acronym MEDINA) has been a three year project funded by the European Commission within the 6th Framework Program. The project team has developed a work programme aiming to improve the current design and operation practices of membrane systems used for water desalination, trying to solve or, at least, to decrease the critical issues of sea and brackish water desalination systems. In the book, the main results achieved in the nine Work Packages constituting the project will be described, and dismissed by the leaders of the various WPs. The following areas are explored in the book: the development of advanced analytical methods for feed water characterization, appropriate fouling indicators and prediction tools, procedures and protocols at full-scale desalination facilities; the identification of optimal seawater pre-treatment strategies by designing advanced hybrid membrane processes (submerged hollow fibre filtration/reaction, adsorption/ion exchange/ozonation) and comparison with conventional methods; the optimisation of RO membrane module configuration, cleaning strategies, reduction of scaling potential by NF; the development of strategies aiming to approach the concept of Zero Liquid Discharge (increasing the water recovery factor up to 95% by using Membrane Distillation - MD; bringing concentrates to solids by Membrane Crystallization or Wind Intensified Enhanced Evaporation) and to reduce the brine disposal environmental impact and cost; increase the sustainability of desalination process by reducing energy consumption (evaluation of MD, demonstration of a new energy recovery device for SWRO installations) and use of renewable energy (wind and solar). Colour figures (PDF, 6MB) Visit the IWA WaterWiki to read and share material related to this title: http://www.iwawaterwiki.org/xwiki/bin/view/Articles/WaterdesalinationandEuropeanresearch

Membrane Engineering for Green Process Engineering

Abstract Green process engineering, which is based on the principles of the process intensification strategy, can provide an important contribution toward achieving industrial sustainable development. Green process engineering refers to innovative equipment and process methods that are expected to bring about substantial improvements in chemical and any other manufacturing and processing aspects. It includes decreasing production costs, equipment size, energy consumption, and waste generation, and improving remote control, information fluxes, and process flexibility. Membrane-based technology assists in the pursuit of these principles, and the potential of membrane operations has been widely recognized in the last few years. This work starts by presenting an overview of the membrane operations that are utilized in water treatment and in the production of energy and raw materials. Next, it describes the potential advantages of innovative membrane-based integrated systems. A case study on an integrated membrane system (IMS) for seawater desalination coupled with raw materials production is presented. The aim of this work is to show how membrane systems can contribute to the realization of the goals of zero liquid discharge (ZLD), total raw materials utilization, and low energy consumption.

4.09 – Membrane Systems for Seawater and Brackish Water Desalination

This chapter provides an overview of current worldwide water stress problem and of the membrane-based technologies under operation in desalination plants. The first part briefly emphasizes the role of desalination technologies as a reliable remedy to water shortages. It also gives a preliminary overview on the existing desalination processes and their reciprocal importance in terms of amount and quality of water produced, as well as of their energy consumption. Membrane desalination processes, their rapid development and spread, along with examples of recent installations are also discussed. A particular emphasis is devoted to reverse osmosis, which has emerged as the leader in existing and future desalination plants. In the second part, the progress made in recent years in membrane desalination processes and the potentialities of membrane operations in integrated systems is presented and discussed. Integrated membrane systems provide the possibility to overcome the limits of the single units and to improve the performance of the desalination process, maximizing recovery factor while decreasing water cost and brine disposal problem.

2.4 Fundamentals in Reverse Osmosis

Today reverse osmosis (RO) is the membrane process that more emphasizes the success of membrane operations because it is, globally, the most widely used desalination technology. RO is the most efficient technology for wastewater reclamation (tertiary treatment), too. This makes it a strong candidate to tackle current and future water shortage problems. Together with advancements in other aspects of RO technology, the understanding of transport phenomena, the intensive research efforts to minimize fouling/biofouling/concentration polarization phenomena, the development of membrane materials have undeniably increased RO performance and efficiency. Therefore, the aim of this chapter is: (i) to illustrate transport mechanisms and models developed to describe solute and solvent fluxes through RO membranes, (ii) to present concentration polarization/fouling/biofouling problem in RO membranes and the means for their control, (iii) to describe the RO membrane materials and modules commercially used, and (iv) to look forward to the novel nanostructured materials that will shape future trends in membrane materials research.

Zero Liquid Discharge in Desalination

Global water stress, raw material depletion, environmental pollution, energy production, and consumption are already severe problems that our modern society have to solve and overcome for maintaining and increasing the quality of our life. Membrane engineering with its various operations is one of the disciplines more involved in the technological innovations necessary to face these strongly interconnected problems. In this work, the most interesting aspects of membrane engineering in water desalination are identified, not only for the production of freshwater but also for the production of energy and for the recovery of metals from the concentrated waste streams of the desalination plants. In particular, the potentialities of integrated membrane-based desalination processes with membrane distillation (MD)/membrane crystallization (MCr)/pressure-retarded osmosis/reverse electrodialysis units are described. Desalination processes designed in this way could become closed systems, exploiting seawater in order to approach zero liquid discharge (ZLD), or near ZLD, and total raw materials utilization.

3.12 Membrane Condenser and Membrane Dryer

Among the large variety of membrane operations, membrane contactors represent relatively new membrane-based devices that are gaining wide consideration. Membrane contactors are systems in which microporous hydrophobic membranes are used not as selective barriers but as a tool for interphase mass transfer operations. All traditional stripping, scrubbing, absorption, and liquid–liquid extraction operations, as well as condensation, dehydration, crystallization and phase transfer catalysis, can be carried out according to this configuration.