Adsorptive exclusion of crystal violet dye from wastewater by using fish scales as an adsorbent

Abstract

Aim of this research paper was to investigate the potential of fish scales as an adsorbent for crystal violet dye exclusion from wastewater and to optimize various adsorption parameters for maximum adsorption of dye. Parameters studied were solution pH, adsorbent dose, contact time, dye concentration, and temperature. Results showed maximum percentage degradation, i.e., 90% under optimized conditions such as pH 12 solution, 0.4 g adsorbent dose, with 40 min of exposure time and 40 ppm of dye concentration at 10 °C solution temperature. Adsorbent was characterized using FTIR, and SEM techniques to explore the functionality and to study morphology of adsorbent, respectively. Results confirmed that carboxyl, amino, phosphate, and sulfonate groups and heterogeneous adsorbent surface was accountable for crystal violet dye adsorption on fish scales. ${\mathrm{pH}}_{\mathrm{pzc}}$ of the fish scale was 8. Adsorption isotherms such as Langmuir, Freundlich, and D-R isotherm models were also investigated. Contact time data was applied to various kinetic models, i.e., pseudo-first order, and pseudo-second order kinetic models. Thermodynamic study was also investigated. Results confirmed that experimental data fitted well to Freundlich isotherm model ($R^{2\mathrm{ }}$= 0.9983) and pseudo second order kinetic model ($R^2\mathrm{ }$= 0.9970) as ARE error analysis values of these models were 1.191692 E + 06 and −160.66, respectively (lower than that of other models. Computed ΔG and ΔH values confirmed adsorption process to be spontaneous and of endothermic kind. Applicability of established procedure with tap water was 78% and regeneration percentage was 72% which showed the effectiveness of fish scales powder for removal of crystal violet dye from wastewater.

Graphical Abstract

Keywords:

• Adsorption
• fish scales
• crystal violet
• desorption

Authors’ contributions

All authors contribute equally to the manuscript.

Availability of data and material (data transparency)

Authors will ensure data transparency.

Conflicts of interest

Authors state no competing financial concerns to influence the work described in this research.

Consent to participate

Not applicable.

Data availability statement

The data that support this study are available in the article and accompanying supplementary file.

Ethics approval

Not applicable.