Analysis of the adsorbent capacity of agroindustrial waste in the removal of dyes

Abstract

AbstractThe research work consisted of analyzing the bio-adsorbent capac-ity of fish scales, cob and corn bracts in the removal of the FD&C Blue No. 1 and FD&C Red No. 40 dyes from synthetic solutions. These materials, considered agro-industrial wastes, may constitute an alternative treatment for the removal of dyes, thus reducing environmental pollution, since being retained on the surface of a solid matrix avoids their dispersion in waterways. The raw materials were treated and characterized in terms of their humidity, and the solutions prepared at 50 ppm of dyes, were subjected to fixed bed adsorption tests, with the modified variables being: particle size of the wastes and pH of the dye solutions; for this, an adsorption module was built to allow standardize condi-tions of the experiment. For calculating the color difference ΔE*ab, it was measured the CIELAB color space coordinates for standard dye solutions and filtered samples, a light booth was built as well as a smartphone application “Colorimeter” was used to guarantee a controlled environment and objectivity of numerical data.The data was submitted to an Analysis of Variance (ANO-VA), using the IBM SPSS Statistics 22.0 software, applied to three types of experimental designs: 2k factorial design, completely ran-domized design and a randomized complete block design. With this research work, it was statistically verified that, when compar-ing the three agro-industrial wastes and the two dyes under study, significant differences were observed between the average values of the color difference of standard-filtered solutions, for which it was determined that the best agro-industrial waste as adsorbent was fish scales; secondly, the corn bracts and, finally, the cob, showing that the bio-adsorbent capacity is similar for residues derived from corn.