On the assessment of dye retention in quartz-based ceramic porous material by optical fiber sensor

• DOI: 10.22533/at.ed.3091916042130

• Palavras-chave: atena

• Keywords: Dye-retention; Silica; Quartz; Optical fiber sensor

• Abstract:

  The utilization of an optical fiber

  reflectometer on the evaluation of filtration

  capability by SiO2 membranes is reported.

  Quartz powder obtained by milling of natural

  quartz was pressed under 30 MPa and

  sintered under ~1000°C for producing 4.35

  mm thickness ceramic membranes. The SEM

  analysis revealed a high porosity material and

  the XRD measurement indicated an α-quartz

  structure. Next, the membranes were tested

  on the retention of commercial food coloring

  (Dr. Oetker, Color Index 16185). The dye was

  diluted in DI water, and solutions were prepared

  with concentrations varying from 0 to 100%

  (v/v). Since the refractive index of solutions

  varies with the dye concentration, the samples

  could be analyzed by a fiber sensor, in which

  the reflected light at the fiber-liquid interface is

  related to the sample refractive index, according

  to the Fresnel equation. The sensor was

  calibrated for the dye diluted solutions, and then

  tested for the filtered samples. It was observed

  that the volumetric concentration varied from

  60% to 50.3% after passing the solution through

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  the porous material. It is a very significant result, since it is commonly necessary to

  use high-tech processes in order to produce materials capable of retaining such small

  structures, and shows that the use of quartz is effective in reducing the concentration of

  a dye commonly used in food industry, being an economical and eco-friendly alternative

  for the treatment of industrial and domestic effluents. Moreover, the methodology of

  using an optical fiber sensor is also attractive for the analysis and control of chemical

  processes, being minimally invasive, chemically inert, and presenting practically realtime

  results.

• Número de páginas: 15