Isolation of chitosan from shrimp shell (Metapenaeus monoceros) as adsorbent for removal of metanil yellow dyes

In this present study, chitosan derived from shrimp shells has been successfully extracted and employed as an adsorbent for metanil yellow dyes using the batch method. The yield of obtained chitosan was calculated as 75.22%, water content 8.9%, with %DD 66.81% based on the Baxter baseline method. The adsorption process indicated that the obtained chitosan reached optimum conditions at pH 4, initial concentration 1000 mg L−1, contact time 60 min, adsorbent heating temperature 120 °C, adsorbent dosage 5 g L−1, and particle size 25 µm with adsorption capacity 199.98 mg g−1. The isotherm and kinetics studies revealed that the adsorption of metanil yellow onto chitosan was fitted to the Langmuir isotherm model and followed the pseudo-second-order model. The thermodynamic parameters (ΔG, ΔH, ΔS) indicated that the adsorption process was spontaneous and exothermic. The adsorption–desorption cycles revealed that NaOH 0.1 M has better performance as a desorbing agent after five adsorption–desorption cycles. The use of adsorbents derived from fishery solid waste in this system presents a sustainable effluent treatment method. The raw materials are derived from renewable natural product sources and are available in large quantities. This study revealed that the chitosan from shrimp shells has good potential as a low-cost and environmentally friendly adsorbent.