Enrico Drioli

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...

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...

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. n nThe 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.

Progress of Nanocomposite Membranes for Water Treatment

The use of membrane-based technologies has been applied for water treatment applications; however, the limitations of conventional polymeric membranes have led to the addition of inorganic fillers to enhance their performance. In recent years, nanocomposite membranes have greatly attracted the attention of scientists for water treatment applications such as wastewater treatment, water purification, removal of microorganisms, chemical compounds, heavy metals, etc. The incorporation of different nanofillers, such as carbon nanotubes, zinc oxide, graphene oxide, silver and copper nanoparticles, titanium dioxide, 2D materials, and some other novel nano-scale materials into polymeric membranes have provided great advances, e.g., enhancing on hydrophilicity, suppressing the accumulation of pollutants and foulants, enhancing rejection efficiencies and improving mechanical properties and thermal stabilities. Thereby, the aim of this work is to provide up-to-date information related to those novel nanocomposite membranes and their contribution for water treatment applications.

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.

1.15 Effect of Solvents on Membrane Fabrication via Thermally Induced Phase Separation (TIPS): Thermodynamic and Kinetic Perspectives

The thermally induced phase separation (TIPS) method is one of the most versatile techniques to fabricate polymeric membranes, with distinct advantages such as a narrow pore size distribution and high reproducibility. Selecting the right solvent is arguably the most important decision to be made for fabricating high-performance membranes via TIPS. Hence, it is crucial to understand the intricate relationship between the solvent and the polymer during TIPS. In this article, we discuss the fundamental aspects of TIPS solution thermodynamics and phase inversion kinetics. Recent advances in the TIPS process and new green solvents that have been identified for fabrication of membranes are discussed in depth.

Extraction Kinetics of As(V) by Aliquat-336 Using Asymmetric PVDF Hollow-Fiber Membrane Contactors

This work focuses on the study of the mass transfer of arsenic(V) through asymmetric polyvinylidene fluoride hollow-fiber membrane contactors using Aliquat-336 as an extractant. In the first part of this work, the fibers were prepared and characterized by SEM and by determining their thickness and porosity. From SEM pictures, an asymmetric structure was obtained that was characterized by an inner sponge-like structure and outer finger-like structure with a pore radius and porosity about 0.11 µm and 80%, respectively. In the second part, the prepared fibers were used as membrane contactors for the study of mass transfer of arsenic(V), investigating the effect of several parameters such as pH, temperature, and initial concentration of the feed. The overall mass transfer coefficient of As(V) was around 6 × 10–6 cm/s.

1.1 From Biological Membranes to Artificial Biomimetic Membranes and Systems

This chapter aims at describing the biological membrane structure and composition with related functions and properties as a model for development of biohybrid membrane systems as well as synthetic membranes able to mimic the specificity and selectivity of the biomembrane. Besides, intriguing properties such as self-cleaning and self-healing will be discussed.

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.

3.13 Membrane Emulsification Advances and Perspectives

Fundamentals of membrane emulsification processes and their application in emulsions and particles production are discussed. A brief comparison with traditional emulsification methods is reported. Parameters governing emulsion micromanufacturing by membrane emulsification in dynamic and static conditions are illustrated. Advances promoted and technological development still needed to fully exploit the technology is pointed out as well. The use of membrane emulsification for the preparation of simple, double emulsions and particles as well as their use in various fields including food, pharmaceutical, and chemical manufacturing is reported. Highlights on the use of membranes to assist nanoprecipitation for the production of micro- and nanosuspensions are also included.