Semester of Graduation

Spring/2018

Degree

Master of Science (MS)

Department

Textiles, Apparel Design and Merchandising

Document Type

Dissertation/Thesis

Abstract

Removal of hazardous acid dyes by economical process using low-cost bio-sorbents from wool industry wastewaters is of a pressing need, since it causes skin and respiratory diseases and disrupts other environmental components. Fish scales (FS), a by-product of fish industry, a type of solid waste, are usually discarded carelessly resulting in pungent odor and environmental burden. In this research, the FS of black drum (Pogonias cromis) were used for the removal of acid dyes (acid red 1 (AR1), acid blue 45 (AB45) and acid yellow 127 (AY126)) from wool industry wastewaters by absorption process with a view to valorizing fish waste and mutual management of both fish by-product and wastewaters of wool industry. The dye absorption process was investigated considering process variables such as dye concentration, amount of fish scale (FS) used, contact time, FS size, temperature, acid (pH), salt, combination of acid and salt, stirring and vacuum as well as the physicochemical characterization of absorbent was conducted through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR) analyses. Microscopic characterization revealed the beautiful architecture of FS with different chemical compositions, TGA revealed that about 50% of scale was mineral and 50% polymer, and finally the evidence of absorption bands of the functional groups for dyes in the colored FS was confirmed by FT-IR analysis. Optimization of process variables represented that maximum dye removal percentages for AR1, AB45, and AY127 were 63.5, 89.3 and 92, and maximum absorptions were 1.8, 2.7 and 3.4mg/g, respectively. The results followed almost the same trend across all three dyes for all process variables. Dyes without any additives (salt and acid) exhibited the best removal performance in terms of percentage of dye removal, whereas the most unusual and inferior outcomes were found in case of fine powdered FS. Two-way analysis of variance (ANOVA) to find the variations in the dye removal percentages among different dyes and process parameters showed that dye types, process parameters and their interactions (dye type X process) had significant effect to the ANOVA model. Over the time, after absorption process the remaining wastewaters formed gelatin probably due to leaching some collagen from the scales. Additional study for characterization of the gel was performed through rheological analysis to find melting point of the gel.

Date

4-6-2018

Committee Chair

Negulescu, Ioan I.

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