CO2 utilization has the potential to support the deployment of CO2 capture technologies through the sale of CO2 based products. This work will evaluate a novel process which combines CO2 utilization with the treatment of reject brines. This is accomplished with the use of a calcined layered double hydroxide (Mg-Al-OH) to remove Cl- from the brine giving an alkaline solution which is then bubbled with CO2 to produce sodium bicarbonate. The sorbent is re-generated via ion exchange. This process holds promise as it is able to address two environmental problems while generating valuable chemical products.
The removal of the anionic dye methyl orange (MO) from aqueous solutions is investigated in batch setup using new class of porous material called metal organic frameworks (MOFs) as promising potential adsorbents. The experimental work examines the adsorption kinetics and thermodynamics of MO on three MOFs including: Cu-BTC, ZIF-8, and Fe-BTC. The preliminary results show that at the same MO initial concentration (15 mg/L) and same amount of adsorbent (100 mg), Fe-BTC has the highest removal efficiency of 97%, followed by ZIF-8 (60%), and finally Cu-BTC (50%). In addition, the kinetic study shows that adsorption of MO on all three adsorbents followed a pseudo-second-order kinetics model with regression constant (R2) in the range of 0.996 - 1.000. All experiments were performed at room temperature (25 ?C) and pH of 5.3.
The utilization of inexpensive renewable and waste resources for producing high added-value products can have positive implications in the sustainable economy of the future. This concept has been the main motivation behind our research, which focuses on the development of versatile adsorbents from inexpensive bioresources and waste feedstock. In this project, lignin, an abundant natural polymer, was blended with recycled poly(ethylene terephthalate), a widely used commodity plastic, and spun into nanofibers of controlled diameter via the electrospinning technique. The nanofibers were carbonized and activated under N2 and CO2 respectively at 600 oC, and transformed into activated carbon nanofibers (ACNFs). These ACNFs have a mesoporous structure with BET surface area around 314 m2/g and average pore width 6.7 nm. The ACNFs were treated with HNO3 in order to increase their active sites for adsorption. Their adsorption capacity was assessed through batch adsorption experiments, for the removal of Pb2+ from aqueous solutions. The ACNFs exhibited an adsorption capacity of 23.75 mg/g.
Rather than use a 3-stage membrane separation system (i.e. MF, UF, and RO process in succession), this project seeks to develop a 1-stage nanofiltration (NF) system to reduce energy consumption and cost. The NF membranes are mixed matrix membranes (MMM) consisting of functionalized fillers from emerging nanomaterials in wastewater treatment - graphene oxide, cyclodextrin and polydopamine - that can simultaneously remove heavy metals, organics, microbes, and suspended solids. These functionalized nanofillers are incorporated into a polyethersulfone (PES) polymer matrix. So far, the highest water flux of 157 LMH has been obtained from the MMM consisting of cyclodextrin nanofiller functionalized with positively charged polyetherimide. Unexpectedly, this membrane also gave the highest rejection of trace contaminants from the treated wastewater, i.e. 90% of trace COD, 88% of trace Fe2+, 92% of trace Cr6+, and 91% of trace Zn2+. Meanwhile, the membranes functionalized with maleic acid and chitosan have shown higher structural integrity due to crosslinking action of these molecules.
Cooling takes up to seventy percent of the power produced in the region, with much of this cooling provided by district cooling systems (DCS). In cooling systems, water provides the main heat transfer medium. Hence, the cooling industry takes up a considerable share of the water demand in the country. The large energy and water requirements for DCS function has prompted a great motivation towards optimizing DCS systems. The effective treatment of cooling water would minimize the issue and limit the consumption. Here, the impact of water quality on DCS performance has been investigated, across several systems in the country, through testing its chemical and biological parameters. The findings show that the system makeup water is clean across sites and the extent of its deterioration is site specific. Following steps will evaluate ultrafiltration as a potential treatment strategy for process water reuse in local DCSs.
The carbon dioxide (CO2) internal corrosion of carbon steel (CS) pipeline has been one of the major issues in the oil and gas industry. In this work, some electrochemical techniques, such as Electrochemical Impedance Spectroscopy (EIS) and Linear Polarization Resistance (LPR), have been employed to study the film persistency of 3 anodic adsorption corrosion inhibitors (CI) on 1080 CS samples in stirred cells. 1% wt. NaCl solution was used with bubbling CO2 in the system. The results indicate that all of the 3 CIs' protection degrade to platform values after a film formation process and CI-A performs much resistant than the others. However, the maximum inhibition resistance? 6.13 kohms comes from CI-B. The corrosion resistance data collected from the LPR and EIS are in good agreement.
There are several advantages, either environmental or economical, of using waste-based composites over ordinary composites. This study aims to provide a preliminary evaluation on the possibility of using the bauxite residue (BR) as a filler in thermoset matrices of an insulating material to reduce the heat loss in buildings. Bauxite residue (BR) is a primary waste in alumina refineries. Unsaturated polyester blended with the filler with a given (BR) concentration (0-60 vol.%) was transformed into solid upon thermoset process. The solid samples produced have been then subjected to different physical and mechanical tests to come up with a product formulation having optimum properties. The results revealed that the BR proved to be a good filler that can be used with unsaturated polyester to produce stable composite. The low value of thermal conductivity (0.08-0.149 W/(m.K)) and very low water retention (< 1.65%) of BR-polyester composite showed promise for constructive applications as a thermal insulator.
As the world turns its eye to the adverse effects of burning fossil fuels in our everyday application, the search for alternative, sustainable and renewable sources of energy is of high interest. Among these, Proton Exchange Membrane Fuel Cells (PEMFCs) are receiving considerable attention. DuPont's perfluorosulfonic acid membrane (Nafion) is the current most successful membrane for PEMFCs. Nafion depends solely on the presence of water molecules necessary for proton conduction [1]. Its conductivity is around 0.1 S cm-1 [2]. PEMFCs usually operate at temperatures around 80 ?C [2]. Increasing the operating temperature (T>1200C) enhances the fuel cell performance in many ways: It increases the kinetics of the redox reactions, reduces catalyst poisoning by CO, higher chance of recovering useful heat as well as solving the problem of accumulated water in the cathode [3,4]. However, high temperature operation is not permitted with the current perfluorosulfonic acid (Nafion) membrane. It dehydrates at temperatures higher than 100 ?C and its proton conductivity dramatically decreases. For example, , Nafion conductivity decreases from 0.066 to 0.00014 S cm-1 at 30?C when the relative humidity (RH) decreases from 100% to 34% [5]. Furthermore, the low glass transition temperature of Nafion (110 ?C) is problematic because above this point the polymer loses its mechanical stability and degradation eventually occurs [6]. Several studies were performed in the literature to either modify existing Nafion membranes or develop a new class of membranes as alternatives for Nafion. Solid proton conductors were proposed in this research. Zirconium phosphate (ZrP) was investigated as a proton conducting material [7]. Zirconium Phosphate was modified with Glycerol. ZrP was prepared by the reaction of Zirconium oxychloride solutions with phosphoric acid. Glycerol was used to modify the ZrP material. The modified ZrP material was then evaluated for proton conductivity using Electrochemical Impedance Spectroscopy (EIS). The preliminary experimental results indicated a higher conductivity compared to the modified ZrP on its own and that is mainly due to the addition glycerol. The second stage of the experimental work will focus on the synthesis of composite membranes based on ZrP and Glycerol. Polyaniline (PANI) and polytetrafluoroethylene (PTFE) are proposed as polymer supports. Polyaniline is a hydrophobic good conducting polymer that is formed from the polymerization of aniline followed by doping with sodium dodecyl sulfate (SDS) to modify its morphology and make it hydrophilic [8]. Initially, the polymerization of polyaniline on polytetrafluoroethylene (PTFE) alone has been conducted and promising conductivity results were obtained in the order of 10-5 S cm-1. Future work will aim at investigating ZrP. Glycerol and PANI supported on PTFE.
CRGO-CuFe2O4 was prepared using co-precipitation method and annealed at 400 oC and 500 oC. The prepared ferrites were characterized using XRD, FTIR and SEM to investigate the catalysts structures, chemical composition, purity, morphology and particle size. The photocatalytic and non-photo-catalytic activity of the catalysts were tested toward phenol degradation using high phase liquid chromatography (HPLC) to measure the phenol and its by-products presented in the reaction system.
The first use of paper dates to 2nd Century (BC). The consumption of paper worldwide has increased by 400% in the past 40 years leading to a rise in deforestation and consequently the global warming. This research focuses on developing calcium carbonate (CaCO3)/polymer composite sheets (paper) instead of the traditionally used wood fiber-based paper with higher mechano-chemical durability. The main aim of this research is to optimize CaCO3 and polymer contents, and their processing conditions for continuous manufacturing of polymer-based papers. Herein, CaCO3/polymer composite sheets with different compositions and their characterization using differential scanning calorimeter and thermogravimetric analyzer, will be presented.
