Biosorption of Cu^{+ 2} by Green Algae, Ulva fasciata: Optimization by Response Surface Methodology

U. fasciata biomass, a green algae was used as adsorbent, investigated and optimized the environmental parameters using central factorial design for the Cu^{+ 2} removal. Biosorption of Cu^{+ 2} involves the functional groups –CO, –OH, and N–H of U. fasciata biomass. Various parameters were estimated using Response Surface Methodology (RSM), including pH (4–6), initial Cu^{+ 2} concentration (60–140 mg L^{− 1}), biomass dosage (0.08–0.40 g L^{− 1}) and temperature (20–40 °C). It was found that the uptake of Cu^{+ 2} by U. fasciata was 62.31 mg L^{− 1} at an initial concentration of 80 mg L^{− 1}, a temperature of 35 °C, and a pH of 5.245. In order to analyze the equilibrium data, applied Langmuir, Freundlich, Langmuir-Friendly (L-R), and Redlich-Peterson (L-R) isotherm models. The multiple mechanisms were involved in the removal of Cu^{+ 2} including chelation, ion-exchange and adsorption on UF biomass. It is believed that the U. fasciata biomass is a suitable material for the removal of Cu^{+ 2} ions from wastewaters.