LAUSR

AbstractThe potential usage of coriander seed spent which is a nutraceutical industrial by-product in the removal of Acid Black 52 (AB52) dye from aqueous solutions was evaluated with respect to various experimental parameters including pH, initial dye concentration, adsorbent dosage, adsorbent particle size, duration of contact time and temperature. The optimal qe value at pH 2, pH 7 and pH 12 was 432 mg g−1, 164 mg g−1 and 220 mg g−1, respectively. Two-level fractional factorial experimental design model yielded maximum adsorption value of 867.00 mg g−1. The influence of each parameter and combination of parameters on the final adsorption capacity of the system has been shown by analysis of variance (ANOVA). Equilibrium data were analyzed by four two-parameter and five three-parameter isotherm models. The dye uptake obeyed pseudo-second order kinetic expression. Intra-particle diffusion showed that the adsorption mechanism was more governed by external mass transfer. AB52 dye adsorption on nutraceutical industrial coriander seed spent (NICSS) was endothermic and almost spontaneous. The NICSS has a highly fibrous matrix with hierarchical porous structure as evidenced by SEM images. The FTIR analysis of the spent confirmed the presence of cellulosic and ligno-cellulosic matter imparting both hydrophilic and hydrophobic properties. The results proved that NICSS efficiently removes AB52 dye from water and textile industrial effluent.Article HighlightsA plausible solution to the ever-increasing problem of myriad tons of spent generated in nutraceutical industry.NIS as low-cost, eco-friendly, abundantly available and ready-to-use biosorbent for the removal of dyes.First-ever use of NIS for remediation of toxic metal-azo dye. For the aforesaid reasons; we believe, the readership of the journal will be most interested in:Attempt to valorize the NIS available in myriad tons.Sustainable clean technology to remove toxic metal-azo dye.Possibilities to use dye-adsorbed spent as filler material for the fabrication of composites.It is envisaged that NIS as new class of biosorbent will foster innovation and provide competitive edge over reported agriculture waste.