Biosorption of a model biocidal agent from aquatic environment using chemically modified Zostera marina L. biowastes

The biosorption of malachite green synthetic dye, a model biocidal agent, on sodium hydroxide-activated Zostera marina L. biomass was investigated. The biosorption ability of the activated biosorbent was interpreted by characterization, optimization, equilibrium, kinetic and thermodynamic studies. It was found that the biosorption capacity decreased with increasing pH, temperature and biosorbent amount, while the biosorption capacity increased with increasing initial synthetic dye concentration. The equilibrium isotherm data showed the best fit to the Langmuir isotherm model and the maximum biosorption capacity was found as 103.834 mg g-1 under optimum conditions (t: 360 min, pH: 4, T: 25 oC, m: 10 mg and C0: 15 mg L-1). Characterization studies showed that the biosorbent had an irregular surface morphology and different active functional groups. Thermodynamic data showed that the biosorption was endothermic and spontaneous. The experimental data were well expressed by the pseudo-second-order kinetic model. The results showed that Z. marina L. biowaste activated with sodium hydroxide can be used as an economical and environmentally friendly biosorbent for biocide removal from aquatic systems.