1 |
Evaluation Of Oxidized Media Filtration Processes For The Treatment Of Hydrogen Sulfide In GroundwaterTrupiano, Vito 01 January 2010 (has links)
This study evaluated alternative sulfide treatment processes for potable water systems that rely on groundwater supplies. Research for this study was conducted at the Imperial Lakes (IL) and Turner Road (TR) water treatment plants (WTPs) in Polk County, Florida. These WTPs are in the process of refurbishment and expansion, and will require the installation of a new groundwater well. The IL and TR WTPs both rely upon groundwater sources that contain total sulfide at concentrations ranging from 1.4 to 2.6 mg/L. Sulfide is a concern because if left untreated it can impact finished water quality, corrosivity, create undesirable taste and odor, and oxidize to form visible turbidity. For this reason, the raw water will require treatment per Florida Department of Environmental Protection (FDEP) "Sulfide Rule" 62-555.315(5)(a). This rule does not allow the use of conventional tray aeration (currently in use at the IL and TR WTPs) for wells that have significant total sulfide content (0.6 to 3.0 mg/L). This research was commissioned because the potential water treatment method identified in the Sulfide Rule (i.e. forced-draft aeration) would not adequately fit within the confines of the existing sites and would pose undue burden to neighboring residents. In addition, an effective sulfide treatment process was desired that offered a low profile, did not necessitate the need for additional complex chemical feed systems, minimized the extent of electrical infrastructure upgrades, and was inexpensive to construct and operate. To meet these goals, several alternative technologies were evaluated at the desktop and bench-scale; these included anion exchange, various oxidation methods, and alternative media filtration processes. From that effort, several processes were selected for evaluation at the pilot scale: bleach (NaOCl) oxidation preceding electromedia filtration; manganese (IV) oxide (MnO2) filtration continuously regenerated with bleach; and ferrate (Fe(VI)) oxidation. Electromedia and MnO2 filtration were shown to be effective for total sulfide treatment. Both processes reduced total sulfide content to below detection levels ( > 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. The use of bleach oxidation ahead of media filtration also produced finished water with low turbidity ( > 1.0 NTU) as compared to conventional tray aeration and chlorination processes (6-16 NTU, as observed in this study). It was determined that the media filtration approach (electromedia and MnO2) was effective for sulfide treatment and met the County's site objectives established at the outset of the project. Ferrate was also shown to reduce total sulfide content to below detection levels ( > 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. An opinion of probable capital costs for installing a sulfide oxidation/filtration process at either the Imperial Lakes or Turner Road WTP was estimated to range from roughly $830,000 to $1,100,000. That equates to a $/kgal capital cost of $0.10 to $0.32 (at 8% for 20 years). An opinion of annual probable bleach chemical costs was estimated to range from $3,500 to $9,800 for the IL WTP and $3,500 to $5,800 for the TR WTP.
|
2 |
PREPARAÇÃO DE COMPÓSITOS TERNÁRIOS FORMADOS POR ÓXIDO DE METAL DE TRANSIÇÃO/POLÍMERO CONDUTOR/CARBONO AMORFO PARA APLICAÇÃO EM SUPERCAPACITORESMarciniuk, Gustavo 11 March 2014 (has links)
Made available in DSpace on 2017-07-24T19:38:12Z (GMT). No. of bitstreams: 1
Gustavo Marciniuk.pdf: 9151594 bytes, checksum: 94a7264c77b0567f7224ef931267fdab (MD5)
Previous issue date: 2014-03-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work refers to the development of a simple and innovative method for the synthesis of ternary composites of different proportions based on amorphous carbon, polyaniline and manganese (IV) oxide for their future use in electrochemical supercapacitors. The process presented here consists, essentially, of 3 parts: (i) at first, it has been performed the oxidative treatment of amorphous carbon and the separated synthesis of pure MnO2 and polyaniline, when all the materials involved were structurally characterized by XRD, FTIR, RAMAN, DLS and SEM, and electrochemically characterized by cyclic voltammetry measurements, in order to
identify its structural, morphological and electrochemical properties and then compared with those presented by the future ternary composites; (ii) synthesis of a binary C/MnO2 composite by the anchoring of the MnO2 particles on the oxidized sites of the amorphous carbon, which represents the first stage on the formation of the ternary composites. Its purpose was to identify possible structural and electrochemical changes caused by MnO2 surface layer in the comparison of the binary composite with its individual components. Therefore, this composite was characterized by the same methods mentioned above; (iii) synthesis and
characterization of ternary composites on different proportions, based on the initial formation of binary C/MnO2 followed by in situ polymerization of aniline monomers on
their surface structure. The purpose of the synthesis in different proportions is to obtain a response profile when small changes in the quantity of the constituent materials are introduced in the ternary composites. The characterization of the ternary composites were carried out by XRD, FTIR, RAMAN, DLS and SEM, which allow to identify possible structural and morphological changes showed by composites compared to the individual components and, by cyclic voltammetry measurements, when it was possible to notice the electrochemical behavior of these composites and define their specific capacitance values in parallel to their processes
of charge storage and ions diffusion. / Neste trabalho, buscou-se desenvolver uma metodologia simples e inovadora para a síntese de compósitos ternários de diversas proporções baseados em carbono amorfo, polianilina e óxido de manganês (IV) visando sua futura utilização em
supercapacitores eletroquímicos. O trabalho consiste basicamente de 3 partes; (i) inicialmente realizou-se o tratamento oxidativo do carbono amorfo e a síntese
individual dos compostos MnO2 e PAni, onde todos os materiais foram caracterizados estruturalmente por DRX, FTIR, RAMAN, DLS e MEV e eletroquimicamente por medidas de voltametria cíclica, afim identificar suas propriedades estruturais, morfológicas e eletroquímicas e compará-las com as apresentadas pelos futuros compósitos ternários; (ii) síntese de um compósito binário C/MnO2 pelo ancoramento das partículas de MnO2 sobre sítios oxidados do carbono amorfo, a qual configura a 1ª etapa da formação dos compósitos ternários. Sua finalidade foi de identificar as possíveis mudanças estruturais e eletroquímicas
ocasionadas pela presença da camada superficial de MnO2 quando comparado o compósito binário aos seus componentes individuais. Para tanto, este compósito foi caracterizado pelos mesmos métodos apresentados acima; (iii) síntese e
caracterização de compósitos ternários de diferentes proporções baseados na inicial formação do binário C/MnO2 seguido da polimerização in situ dos monômeros de anilina sobre sua estrutura superficial. A abordagem da síntese em diferentes proporções torna possível a obtenção de um perfil de resposta quando são introduzidas nos compósitos ternários pequenas modificações na quantidade dos materiais constituintes. A caracterização dos compósitos ternários foi realizada pelas técnicas de DRX, FTIR, RAMAN, DLS e MEV, as quais permitem identificar possíveis mudanças estruturais e morfológicas apresentadas pelos compósitos frente aos componentes individuais, e, por medidas de voltametria cíclica, onde foi possível observar o comportamento eletroquímico destes compósitos e definir seus valores de capacitância específica juntamente com seus processos de
armazenamento de carga e difusão de íons.
|
Page generated in 0.0447 seconds