Marine green algae Codium iyengarii as a good bio-sorbent for elimination of reactive black 5 from aqueous solution

Abstract

The green seaweeds Codium iyengarii (C. iyengarii) was used to prepare as an adsorbent surface for the deletion of Reactive Black 5 (RB 5) from aqueous solution via adsorption. The batch technique was adopted under the optimal condition of amount of adsorbent, agitation time, concentration of dye, and at neutral and low pH. The depletion in concentration of the dye was monitored by Schimadzo 180 AUV/Visible spectrophotometer. It was initially monolayer adsorption, which showed multilayered formation later on with the passage of time at low and neutral pH. The Results displayed that adsorptive ability of C. iyengarii was 1.95-3.82mg/g with an elevation in primary application of dye contents (50ppm-70 ppm). The elimination data were well stable into the Langmuir and Freundlich adsorption isotherm equations. The Langmuir (R2 =0.9848) and Freundlich (R2 =0.9441) constants for biosorption of RB 5 on green algae were determined. The coefficient relation values suggested that the Langmuir isotherm was well fitted. It explained the interaction of surface molecules, which helps in well organization of dye molecules in a monolayer formation initially on algal biomass. The pseudo first and second order rate equations were applied to link the investigational statistics and found that the second order rate expression was found to be more suitable for both the models. The absorption spectrum of RB 5 before and after adsorption with respect to time was monitored which clearly indicate that C. iyengarii was much effective surface at very low quantity.