Engineering Commons^™

Graphene Reinforced Pvdf Nanofibers Fabricated With The Forcespinning® Method For Water Desalination Applications, Elmmer A. Vera Alvarado, Md. Abdur Rahman Bin Abdus Salam, Ali Ashraf, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Direct contact membrane distillation (DCMD) is a thermally driven energy and cost-efficient desalination technique where low-grade energy from solar or waste heat from plants can be used to recover fresh water from high saline water. The DCMD technique allows both the feed and permeate solutions to be in contact with the membrane, where vapor from the feed gets condensed in the permeate side once it collides with low- temperature water. Polyvinylidene fluoride (PVDF) nanofiber membranes were prepared by the ForceSpinning® method, these were later dip coated in graphene solutions prepared with different solvents. The ForceSpinning® method, unlike electrospinning, operates in …

Maitreya Desalination, Riley Taft, Hudson Kispert, Brendan Dizon

Mechanical Engineering

This document relays the design and manufacture of a dual power input Reverse Osmosis desalination unit. It's power sources are electric drive and human power via recumbent seated cycling. Fresh water outputs range from 4 - 7 GPH for human power inputs of 150 - 280 Watts depending on the selected gearing ratio from the derailleur.

Performance Evaluation Of A Coupled Photovoltaic-Thermal Solar Powered Desalination Pilot System, Martin Chavarin

Open Access Theses & Dissertations

A pilot scale coupled photovoltaic-thermal solar powered desalination system was evaluated at the Brackish Groundwater National Desalination Research Facility (BGNDRF). The pilot system consisted of a 3-kW photovoltaic-thermal (PVT) solar panel array and a 2.3 kW photovoltaic (PV) array coupled with a 4 gal/min single-stage 4 membrane reverse osmosis (RO) desalination system. A heat exchange system was in place to provide simultaneous cooling for the PVT system and heating to the RO system feed water. This system was evaluated with three objectives in mind. The first objective was to identify whether cooling of the PVT panels resulted in a significant …

Rapid Synthesis Of Dual-Layered Covalent Organic Framework Membranes Via Interfacial Polymerization With Enhanced Desalination Performance, Miguel Angel Jaimes

Theses and Dissertations

As a consequence of disrupting the water cycle via human interventions, such as climate change, humanity is facing global water crises. The water crises are wide ranging, but often associated with the deterioration of a local water cycle’s capacity to support a population. This capacity is reduced on a global scale through the atmosphere via climate change, but on a local scale, it can be reduced because of an over extraction of resources, alteration of ecosystems, and water pollution. The deployment of desalination plants is growing around the world. Reverse osmosis (RO) desalination is much more efficient than the thermal …

Computational Modeling Of Patterned Membranes And Spacers For Improved Hydrodynamics And Fouling Reduction In Reverse Osmosis Water Treatment Processes, Zuo Zhou

All Dissertations

My research goal is to discover ways to improve the hydrodynamics of reverse osmosis (RO) membrane systems through creative membrane surface patterning and spacer designs. Since concentration polarization (CP) usually promotes membrane fouling, improving hydrodynamics would result in reduced fouling and better membrane performance. With computational fluid dynamics (CFD), we can explore dozens or even hundreds of models with different geometries and boundary conditions. Through plotting their velocity profile, streamlines, shear stress, pressure profile, concentration profile, and so on, we can determine which design would lead to the best performance.

At first, patterned membranes were evaluated and compared with flat …

An Exploration Of The Application Of Desalination In Disaster Relief, Emma Sager

Senior Honors Theses

This paper aims to explore the application of small-scale desalination systems to provide clean water in the wake of marine natural disasters. A lack of clean water is a devastating impact of many natural disasters. Desalination technologies, both thermal and membrane, show potential for being scaled down and self-powered by renewable energy. Desalination can transform ocean water and contaminated drinking water with a high salt content into drinkable, usable water. While these techniques are not perfected, and the solution to a need for clean water is multifaceted, desalination shows potential. Through further research and ever-advancing technology, small-scale desalination could develop …

Polyethersulfone Thin-Film Nanocomposite Membrane Embedded With Amine-Functionalized Graphene Oxide For Desalination Applications, Ahmed Bahaeldin

Theses and Dissertations

Thin-film nanocomposite (TFN) desalination membranes were prepared based on a polyethersulfone (PES) support, where the polyamide (PA) layer was embedded with amine-functionalized graphene oxide (GO). The effect of adding various concentrations of functionalized and un-functionalized GO on the desalination performance, hydrophilicity, and morphology of the membranes was additionally assessed throughout this work. Scanning electron microscopy (SEM) measurements were used to assess the morphology of the membranes in combination with Brunauer-Emmett-Teller (BET) analysis. Contact angle measurements were used to gauge the hydrophilicity of the synthesized membranes. The membrane with the best desalination performance contained 1x10^-3 wt/vol% of functionalized GO in …

Elevation-Distributed Multistage Reverse Osmosis Desalination With Seawater Pumped Storage, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

A seawater reverse osmosis (RO) plant layout based on multistage RO with stages located at different elevations above sea level is described. The plant uses the weight of a seawater column from pumped storage as head pressure for RO (gravity-driven multistage RO) or to supplement high-pressure pumps used in RO (gravity-assisted multistage RO). The use of gravitational force reduces the specific energy for RO compared to using high-pressure pumps. By locating the RO stages at different elevations based on demand sites, the total specific energy consumption for RO and permeate transport to different elevations above sea level is reduced from …

Wave Goodbye To Salt, Andy Wu, Amanda Olla, Solie Grantham, Charlie Sinclair

Mechanical Engineering

Our team of Cal Poly Mechanical Engineers ideated, designed, built, and tested a system to help combat the growing problem of widespread drought in coastal and island communities. We developed a proof-of-concept model of a wave powered, mechanical system to desalinate ocean water using a reverse osmosis process. From topical research, it was found that there are many ways to harness a portion of the huge amount of energy that the ocean provides. While large scale ocean water desalination plants are already in operation, smaller scale desalination units powered by ocean waves are largely underdeveloped. Our relatively small and inexpensive …

Investigation Of A Simultaneaous Direct And Indirect Contact Dehumidifier Using Parallel Strings For Hdh Desalination, Josue Perez Perez

Theses and Dissertations

Freshwater is a limited and precious resource. Currently, half a billion people in the world face sever water scarcity all year round. Humidification dehumidification (HDH) systems have received special attention among the variety of small-scale desalination technologies due to its potential to create affordable and sustainable seawater desalination, especially when combined with natural power sources such as waves, wind, and solar rays. Improvements in the development of HDH desalination systems have been achieved in recent years. Nonetheless, the improvements that have received most attention focus on solar heaters and humidifiers. Dehumidification systems have often been adapted from air conditioning condensation …

Diffusion Of A Salt In An Aqueous Media, Aldaly Pineda Hernandez

Chemical Engineering Undergraduate Honors Theses

Diffusion is defined as the net transfer of a molecule from a high concentration region to a low concentration region. The concept of diffusion is used in a very important process called "desalination." Desalination is a separation process used to reduce the salt content dissolved in brackish water to make it suitable for human consumption, irrigation, and industrial use.

In desalination plants, it is important to monitor the constantly changing salt content of water, partly due to the diffusive effect. The main purpose of this experiment was to study the diffusion of NaCl in water at two NaCl concentrations. The …

Cloth-Water Interaction For Air Humidification In Hdh Desalination, Alejandro Corona Martinez

Theses and Dissertations

The humidification-dehumidification (HDH) desalination technology is a promising desalination process that has the potential to provide cost-effective and environmentally friendly saltwater desalination, especially when combined with renewable energy sources. The working principle mimics the natural hydrologic cycle, involving the evaporation of seawater into water vapor (humidification) and condensation into freshwater (dehumidification). HDH desalination can be land-based or ocean-based. Some of the advantages of ocean-based systems include removing pretreatment processes, utilization of ocean energy (i.e. thermal and kinetic), and eliminating brine production. This study focuses on the design and experimental testing of a novel humidifier …

Koh-Based Modified Solvay Process: Optimization And Kinetics Studies, Aya Abdel-Hamid Mourad

Dissertations

While desalination of seawater is important for meeting the water demand, the technology produces large volumes of reject brine and CO₂, causing environmental pollution. Solvay process (based on ammonia, NH₃) and modified Solvay process (based on calcium oxide, CaO) try to manage these wastes. However, more attention is needed to overcome different limitations of these processes such as, alkaline solubility, operating temperature, maintaining high pH value, and low sodium (Na⁺) removal efficiency, which does not exceed 35%. The aim of this work is to introduce an alternative alkaline, namely potassium hydroxide (KOH) and investigate …

Scale-Up Of Flow-Electrode Capacitive Deionization Method For Hard Water Softening, Noah Henry

Williams Honors College, Honors Research Projects

This study’s purpose is to further document a capacitive deionization design that could be capable of purifying H₂O at a household scale where clean water is otherwise unobtainable in applicable regions of the world. The hypothesis behind this study was continuously larger scaled electrochemical cell-units would increase their water softening capabilities in sustainable fashion. The trend at which performance will scale is currently unknown. The units studied were constructed using graphite plates, anion exchange membranes, cation exchange membranes, and Teflon channels. Three streams, two being CaCl₂ solutions in DI H₂O (one being concentrated with CaCl …

Process Optimization For An Integrated Reverse Osmosis—Pressure Retarded Osmosis Pilot-Scale System Operated On Humboldt Bay, Ca, Galen O'Toole

Cal Poly Humboldt theses and projects

Pressure retarded osmosis (PRO) is an emerging osmotic power technology that could mitigate the major challenges faced by seawater reverse osmosis desalination (RO): brine disposal and high energy consumption. The primary focus of this paper is process optimization for a linked seawater reverse osmosis (RO) and pressure retarded osmosis (PRO) water purification system. PRO generates power by using osmosis to “pump” water through a membrane from low pressure and low concentration to high pressure and high concentration (RO brine). This commercial-scale pilot effort explores process optimization for pressure retarded osmosis as an industrial process rather than theoretical or experimental process. …

Thermoeconomic Analysis And Multi-Objective Optimization Of A Novel Trigeneration System Consisting Of Kalina And Humidificationdehumidification Desalination Cycles, Pooria Behnam, Meysam Faegh, Iman Fakhari, Pouria Ahmadi, Ehsan Faegh, Marc A. Rosen

Research outputs 2022 to 2026

Low-temperature geothermal heat sources have the highest share of geothermal energy in the world. Utilization of these heat sources for energy and freshwater generation can play an important role in meeting energy and freshwater demands. To do so, this study aims to propose a novel trigeneration cycle powered by low-temperature geothermal sources. The proposed system, which is an integration of Kalina and humidification-dehumidification (HDH) cycles, is used for the generation of electricity, heating, and freshwater. For the Kalina cycle, an evaporative condenser is used. It also acts as a humidifier and heater of the humidification-dehumidification desalination cycle, resulting in a …

Evaluation Of Electrodialysis Desalination Performance Of Novel And Conventional Ion Exchange Membranes, Ahm Golam Hyder

Open Access Theses & Dissertations

It was revealed from relevant recent literature that the electrodialysis (ED) desalination performance of commercial and laboratory-made ion exchange membranes (IEMs) had been studied previously but not in a systematic way so that the planners, designers, and engineers can evaluate a trade-off in selecting the suitable IEMs and optimum ED experimental conditions for their desired outcomes such as high ion selectivity, high salinity removal, high water recovery, low energy consumption, or low water transport. Furthermore, the existing conventional and laboratory-made IEMs reported previously showed various technical and economical limitations with respect to permeability, permselectivity, ion selectivity, electrical resistance, stability (mechanical, …

Sustainability Assessment Of A Pressure Retarded Osmosis System, Samar Al Mashrafi

USF Tampa Graduate Theses and Dissertations

Desalination has the potential to provide a stable supply of clean fresh water and meet the increasing water demands; however, this process does come with a few challenges such as high energy consumption, high energy cost, and a discharge of a highly concentrated brine. Pressure retarded osmosis (PRO) is a technology that could work as an efficient energy recovery technology for desalination since it can significantly reduce the energy consumption and dilute the brine before discharge. Studies have assessed the economic feasibility of PRO systems; however, these studies have not addressed the environmental sustainability of the systems. Thus, there is …

Desalination For Sustainable Water Production With An Emphasis On Low Pressure Distillation, Jessica Vivian Savage

Doctoral Dissertations and Master's Theses

Freshwater resources depletion is a growing concern. This freshwater scarcity motivates research into seawater desalination as a means for alleviating the stresses on water demands. The primary methods of desalination include filtration and distillation. This paper explores the potential energy savings of vacuum distillation for seawater desalination to reduce the amount of energy needed to achieve phase change.

Depending on the vacuum boiler design, the vaporization mechanism may be boiling, evaporation, or cavitation. There is very little literature on cavitation that involves mass transfer, so cavitation is not developed here. This thesis focuses on standard models for boiling and evaporation …

Evaluation And Sizing Of Solar Powered Reverse Osmosis Water Desalination System, Sandip Subedi

Honors Theses

About 71 % of the surface of Earth is water, out of which around 2.5 % is freshwater. The majority of the surface of Earth is occupied by seawater which also contains dissolved salt. The salt concentration in seawater makes it toxic to humans because the human body is unable to get rid of the salt that comes from seawater. The demand for fresh water is increasing due to the rise in global population. In this context, desalinated seawater is considered as a viable resource to meet the growing demand for fresh water. Desalination process is highly energy intensive due …

Investigating The Performance Of Hydroponic Nutrient Solutions As Potential Draw Solutions For Fertilizer Drawn Forward Osmosis, Mohamed Bassiouny Abu Qersh

Theses and Dissertations

This research project aims at investigating the performance of hydroponic nutrient solutions as draw solutions for desalination using the fertilizer drawn forward osmosis (FDFO) process. Six different lettuce and leafy greens hydroponic nutrient stock solutions were prepared according to the literature and used in this study and tested on a bench-scale forward osmosis unit as draw solutions for the process. The feed solutions for the process was de-ionized water mixed with Sodium Chloride in different concentrations to represent different salinities of brackish groundwater. The draw efficiency of each solution was measured based on water flux, reverse solute flux, water recovery, …

Application Of The Vortex Fluid Device (Vfd) In Polysulfone Synthesis And Ultra-Filtration Membrane Fabrication For Water Treatment Purposes, Aghil Igder

Theses: Doctorates and Masters

Extensive studies have been performed to improve key properties of filtration membranes via controlling the fabrication process conditions as well as physical and/or chemical modification of the polymers used in membrane fabrication. The Vortex Fluid Device (VFD) is a newly invented platform which has found many applications in materials science and clean technology. The unique features of the VFD originate from a combination of different effects (e.g., micro-mixing, viscous drag, microfluidic flow, enhanced mass transfer) all resulting in faster, greener, and more efficient and better controlled chemical reactions. The main aims of this project are: (i) to investigate the utility …

Recent Advancements In The Application Of New Monomers And Membrane Modification Techniques For The Fabrication Of Thin Film Composite Membranes: A Review, Javad Farahbakhsh, Vahid Vatanpour, Mahsa Khoshnam, Masoumeh Zargar

Research outputs 2014 to 2021

Thin film composite (TFC) membranes have been experiencing significant modifications recently aiming to improve their structure, properties and separation efficiency. One of the promising modifications to tailor the membranes more efficient is changing the materials used. m-phenylene diamine (MPD), piperazine (PIP), and trimesoyl chloride (TMC) are the most common monomers used to fabricate TFC membranes. Recent studies have introduced several alternatives to these traditional monomers showing significant contribution of these monomers to the physicochemical properties of the membranes (e.g., surface roughness, hydrophilicity, cross-linking density, chemical structure) as well as membranes' separation efficiency. Emergence of more favorable functional groups such as …

Optimizing Membrane Distillation With Solar Thermal Collectors, Andrew Mason, Ben Shulders, Siamak Nejati

UCARE Research Products

With rising human populations, the demand for freshwater is an ever-growing problem. One emerging technology to combat this problem is membrane distillation (MD). MD has several advantages for water desalination including 100% rejection of solute (salt, heavy metals, etc.) and mergeability with other affordable energy sources (solar heat, electric resistance, etc.) However, at the moment the specific energy consumption (SEC) of MD is very high due to low water production rates and large energy inputs to heat water. In a solar‐assisted design for MD, the high cost of solar collectors (~$200/m2) inhibits the low cost of water production in comparison …

Surface Modifications Of Reverse Osmosis Membranes For Removal Of Bromide And Reduction Of Fouling, Joseph Seo

Master's Theses

Reverse osmosis (RO) is widely used for water reuse and desalination. Although RO membranes are known for their high salt rejection and practical permeate flux, their performance can be impaired by fouling, and their removal of some disinfection byproducts and their precursors (e.g., bromide, N-Nitrosodimethylamine [NDMA]) does not meet drinking water standards. RO membrane modifications have been widely studied to overcome these limitations. In this research, RO membranes were grafted with cationic polymers to induce a positive charge on the RO membrane surface. This modification aimed at enhancing the rejection of negatively charged bromide ions by removing them from solution …

Investigation Of New Forward Osmosis Draw Agents And Prioritization Of Recent Developments Of Draw Agents Using Multi-Criteria Decision Analysis, Jodie Wei Yu

Master's Theses

Forward osmosis (FO) is an emerging technology for water treatment due to their ability to draw freshwater using an osmotic pressure gradient across a semi-permeable membrane. However, the lack of draw agents that could both produce reasonable flux and be separated from the draw solution at a low cost stand in the way of widespread implementation. This study had two objectives: evaluate the performance of three materials — peptone, carboxymethyl cellulose (CMC), and magnetite nanoparticles (Fe₃O₄ NPs) — as potential draw agents, and to use multi-criteria decision matrices to systematically prioritize known draw agents from literature for …

Engineering Ionomer Materials For Addressing Ohmic Resistances In Electrochemical Desalination And Waste Heat Recovery, Varada Menon Palakkal

LSU Doctoral Dissertations

Water scarcity and energy availability present important challenges that need to be addressed in the coming centuries. In the front of water technologies, desalting brackish water is of extreme importance for thermal electric power plants, chemical manufacturing plants, and other industrial operations that treat and reuse their water utilities. Membrane capacitive deionization (MCDI) is an energy efficient desalination technique that has drawn attention from commercial entities. Most material research studies on MCDI focus on enhancing electrode performance while little emphasis is given to rationale design of ion-exchange membranes (IEMs). In this work, the ionic conductivity, permselectivity, and thickness for three …

Imaging Of Membrane Concentration Polarization By Nacl Using 23na Nuclear Magnetic Resonance, Masoumeh Zargar, Ryuta Ujihara, Sarah J. Vogt, Johannes S. Vrouwenvelder, Einar O. Fridjonsson, Michael L. Johns

Research outputs 2014 to 2021

Forward osmosis (FO) and reverse osmosis (RO) membrane processes differ in their driving forces: osmotic pressure versus hydraulic pressure. Concentration polarization (CP) can adversely affect both performance and lifetime in such membrane systems. In order to mitigate against CP, the extent and severity of it need to be predicted more accurately through advanced online monitoring methodologies. Whilst a variety of monitoring techniques have been used to study the CP mechanism, there is still a pressing need to develop and apply non-invasive, in situ techniques able to produce quantitative, spatially resolved measurements of heterogeneous solute concentration in, and adjacent to, the …

Reverse Osmosis; Addressing Freshwater Shortage With Sustainable Desalination, Jessica Savage

Sustainability Conference

Water security is an imperative part of high-functioning societies. Currently, large populations of the globe live in water-impoverished or water-stressed areas. With climate change and growing global populations, projections show more people being impacted by issues of water shortage.

One solution to water security is the implementation of desalination, specifically with reverse osmosis systems. This presentation walks through the history, capabilities, future work, and explanations on how reverse osmosis systems work. With continued research on improving desalination, communities in both developed and developing nations around the world can work towards total water security.

Evaluation And Modeling Of Electrodialysis For High-Recovery Brackish Water Desalination, Shahrouz Jafarzade Ghadimi

Open Access Theses & Dissertations

This research investigates the feasibility of desalination of brackish water with electrodialysis (ED), using laboratory testing and mathematical modeling. Several experiments were performed to characterize ion-specific transport and to evaluate tradeoffs between salinity removal and specific energy consumption. A 200 cm2 Ameridia ED stack was used to perform desalination experiments with real brackish groundwater from the Kay Bailey Hutchison desalination plant in El Paso, Texas, and the results showed limiting current density of 160 A/m2 for 5 cm/s. A higher conductivity reduction was observed for flow velocity of 5 cm/s compared to 13 cm/s. Ion transport selectivity (based on relative …