Macroalgae of Iridaea cordata as an efficient biosorbent to remove hazardous cationic dyes from aqueous solutions

In the present work, Iridaea cordata (IC), a red marine macroalgae, was used as an efficient biosorbent for the removal of crystal violet (CV) and methylene blue (MB) dyes from aqueous solutions. The effects of pH (5, 7, and 9) and IC concentration (1, 3, and 5 g L−1) on the biosorption were studied through a 32 full factorial design. Under the optimal conditions (pH: 7, biosorbent concentration: 1 g L−1), biosorption kinetic studies were developed and the obtained experimental data were evaluated by pseudo-first order and pseudo-second order models. The results showed that the pseudo-second order model was in agreement with the experimental kinetic data for both dyes. Equilibrium studies were also carried out, and results exhibited good concordance with the Brunauer–Emmett–Teller isotherm. The biosorption capacities were 36.5 and 45.0 mg g−1 for CV and MB dyes, respectively. The dye removal percentages were around 75% for CV and 90% for MB. Thermodynamically, the biosorption process proved to be exothermic, spontaneous, and favorable. These results showed that IC biomass is a promising biosorbent for removal of CV and MB dyes from aqueous solutions.

Life history bias in endophyte infection of the Antarctic rhodophyte, Iridaea cordata

Endophytic organisms are known to have varied effects on their host organism in terrestrial and marine environments. In previous studies on marine algae, these symbioses range from innocuous to pathogenic depending on the host and endophyte species. The present study further assessed a pathogenic relationship between filamentous algal endophytes and a red algal host from the western Antarctic Peninsula. We analyzed endophyte presence (appearance of filamentous thalli) in the three life history stages of