Dye removal from wastewater using shrimp chitosan as an eco-friendly adsorbent

In this research, application of fishery wastes as locally available, cheap, eco-friendly, non-toxicity, reusable, abundant biodegradable resources and highly efficient adsorbent was studied for Direct Blue-86 (DB-86) removal fromaqueous solution.

Comparison of the adsorption of DB-86 by chitosan produced from three different fishery wastes (shrimp, crab and squid collected from Persian Gulf) has been investigated. Effects of adsorbent dosage, pH, flow rate, ionic strength, interfering ions and dyes were evaluated.

The results indicated that maximum removal of dye (~ 100%) was obtained by passing 100 mL of DB-86 (50 mg L-1, pH=2) through a column containing 0.5 g chitosan by using continuous method (fixed-bed) at room temperature (25 ± 2 ºC). Maximum desorption of 72% was achieved at alkaline medium (pH=13.5). It was shown that equilibrium isotherm could be fitted by the Langmuir equation. The maximum adsorption of chitosan (qm) and the energy of adsorption were calculated as nearly 60 mg/g and 3.6 mg-1, respectively.

Chitosan was successfully used for removal of DB-86 from spiked Karoon River sample and the effluent of Pars Paper Factory, a local pulp and paper factory in Ahvaz. Results represent of three replicated experiments.