Matching Items (4)

133693-Thumbnail Image.png

Computational Modeling and Experimentation of Pervaporation Membrane Processes for Brackish Water Recovery

Description

Fresh water is essential to the human population and is an integral component in global economics for its multiple uses, and population growth/development cause concern for the possible exhaustion of the limited supply of freshwater. A combined computational and experimental

Fresh water is essential to the human population and is an integral component in global economics for its multiple uses, and population growth/development cause concern for the possible exhaustion of the limited supply of freshwater. A combined computational and experimental approach to observe and evaluate pervaporation membrane performance for brackish water recovery was done to assess its efficiency and practicality for real world application. Results from modeling conveyed accuracy to reported parameter values from literature as well as strong dependence of performance on input parameters such as temperature. Experimentation results showed improved performance in flux by 34%-42% with radiative effect and then additional performance improvement (9%-33%) with the photothermal effect from carbon black application. Future work will include improvements to the model to include scaling propensity and energy consumption as well as continued experimentation to assess quality of pervaporation in water recovery.

Contributors

Agent

Created

Date Created
2018-05

136494-Thumbnail Image.png

Solution-Cast Membranes for Wastewater Recovery: A New Chemical-Resistant Nanocomposite Design

Description

The goal of this research project is to create a mixed matrix membrane that can withstand very acidic environments but still be used to purify water. The ultimate goal of this membrane is to be used to purify urine both

The goal of this research project is to create a mixed matrix membrane that can withstand very acidic environments but still be used to purify water. The ultimate goal of this membrane is to be used to purify urine both here on Earth and in space. The membrane would be able to withstand these harsh conditions due the incorporation of a resilient impermeable polymer layer that will be cast above the lower hydrophilic layer. Nanoparticles called zeolites will act as a water selective pathway through this impermeable layer and allow water to flow through the membrane. This membrane will be made using a variety of methods and polymers to determine both the cheapest and most effective way of creating this chemical resistant membrane. If this research is successful, many more water sources can be tapped since the membranes will be able to withstand hard conditions. This document is primarily focused on our progress on the development of a highly permeable polymer-zeolite film that makes up the bottom layer of the membrane. Multiple types of casting methods were investigated and it was determined that spin coating at 4000 rpm was the most effective. Based on a literature review, we selected silicalite-1 zeolites as the water-selective nanoparticle component dispersed in a casting solution of polyacrylonitrile in N-methylpyrrolidinone to comprise this hydrophilic layer. We varied the casting conditions of several simple solution-casting methods to produce thin films on the porous substrate with optimal film properties for our membrane design. We then cast this solution on other types of support materials that are more flexible and inexpensive to determine which combination resulted in the thinnest and most permeable film.

Contributors

Agent

Created

Date Created
2015-05

135478-Thumbnail Image.png

Ionic Liquids to Lab: Investigating an Emerging Water Filtration Challenge to Engineering Nanofiber Polymer Membranes as Next-Generation Solutions for Water Purification

Description

The following thesis documents a two-fold approach to investigate challenges pertaining to water purification, first through a meta-analysis of ionic liquid toxicity, then through experimentation aimed at developing water pre-treatment membranes. Ionic liquids (ILs) are salts with low melting points,

The following thesis documents a two-fold approach to investigate challenges pertaining to water purification, first through a meta-analysis of ionic liquid toxicity, then through experimentation aimed at developing water pre-treatment membranes. Ionic liquids (ILs) are salts with low melting points, typically liquid at room temperature. Several extraordinary physical attributes, e.g. low viscosity, high conductivity, low to no vapor pressure, etc., and seemingly unlimited combinations available, have pushed IL research to the forefront of many research fronts. Concerns are raised as ionic liquids are rushed into commercial production without sufficient environmental regulation. Research has shown that the chemicals are in fact toxic, yet have developed a reputation for being “green” chemicals due to select physical attributes and applications. The meta-analysis discussed focuses on industry perception of ionic liquid toxicity through a patent review, and considers toxicity of ILs comparatively against other chemical families with well-established toxicity. The meta-analysis revealed that the total patent literature pertaining to ILs (n=3358) resulted in 112 patents that addressed the toxicity of ILs, and notably few (n=17) patents defined ILs as toxic, representing only 0.51% of the evaluated body of work on intellectual property claims. Additionally, toxicity of ionic liquids is comparable to that of other chemical families.
The objective of the experimentation was to explore the effect of crosslinker chain length on the morphology of nanofiber mats. Specifically, poly(vinyl alcohol (PVA) was electrospun into nanofiber mats and poly(ethylene) glycol bis(carboxylic acid) (PEG diacid) was used as the crosslinking agent. As-spun fibers had average fiber diameter of 70 ± 30 nm with an average pore size of 0.10 ± 0.16 μm^2. The fiber diameter for the mats crosslinked with the shorter PEG diacid (Mn = 250) increased to 110 ± 40 nm with an average pore size of 0.11 ± 0.04 μm^2. The mats crosslinked with the longer PEG diacid (Mn = 600) had fiber diameters of 180 ± 10 nm with an average pore size 0.01 ± 0.02 μm^2.

Contributors

Agent

Created

Date Created
2016-05

137439-Thumbnail Image.png

33 Buckets: Distributing Clean Water in Bangladesh

Description

Bangladesh is facing one of the largest mass poisonings in human history with over 77 million people affected by contaminated water each and every day. Over the last few years, the 33 Buckets team has come together to help fulfill

Bangladesh is facing one of the largest mass poisonings in human history with over 77 million people affected by contaminated water each and every day. Over the last few years, the 33 Buckets team has come together to help fulfill this clean water need through filtration, education, and an innovative distribution system to inspire and empower people in Bangladesh and across the world. To start this process, we are working with the Rahima Hoque Girls' school in the rural area of Raipura, Bangladesh to give girls access to clean water where they spend the most time. Through our assessment trip in May 2012, we were able to acquire technical data, community input, and partnerships necessary to move our project forward. Additionally, we realized that in many cases, including the Rahima Hoque school, water problems are not caused by a lack of technology, but rather a lack of utilization and maintenance long-term. To remedy this, 33 Buckets has identified a local filter to have installed at the school, and has designed a small-scale business focused on selling clean water in bulk to the surrounding community. Our price point and association with the Rahima Hoque Girls' school makes our solution sustainable. Plus, with the success of our first site, we see the potential to scale. We already have five nearby schools interested in working to implement similar water projects, and with over 100,000 schools in Bangladesh, many of which lack access to the right water systems, we have a huge opportunity to impact millions of lives. This thesis project describes our journey through this process. First, an introduction to our work prior to the assessment trip and through the ASU EPICS program is given. Second, we include quantitative and qualitative details regarding our May 2012 assessment trip to the Rahima Hoque school and Dhaka. Third, we recount some of the experiences we were able to participate in following the trip to Bangladesh, including the Dell Social Innovation Challenge. Fourth, we examine the technical filtration methods, business model development, and educational materials that will be used to implement our solution this summer. Finally, we include an Appendix with a variety of social venture competitions and applications that we have submitted over the past two years, in addition to other supplementary materials. These are excellent examples of our diligence and provide unique insight into the growth of our project.

Contributors

Agent

Created

Date Created
2013-05