Environmental performance of two marine algae Ulva fasciata and Pterocladia capillacea in the biological treatment of four reactive dyes from aqueous solutions based on fresh and dried biomass

Abstract

The runoff of textile dye effluents into public water bodies is a major environmental and health problem. Color removal, in particular, has recently become of substantial scientific interest, as revealed by the multitude of related research reports. The present study focused on measuring the efficiency of two marine algae, Ulva fasciata and Pterocladia capillacea, in bio-removal of four synthetic dyes (RY2, RR195, RB19, and RB5) based on the fresh and dried biomass of the tested algal species. According to the highest removal efficiencies of the dyes, two algal species were chosen from among nine different algae. Bio-removal efficiency was examined under the effects of salinity and contact time. The results of this experiment revealed that algae achieved high bio-removal efficiency of the examined dyes in both fresh and saline water, but the removal percentages were higher in saline water compared to fresh conditions. The highest removal percentage recorded after 8 h by fresh U. fasciata in saline water reached 82.75 and 83.23% for RY2 and RR195 dyes, respectively. Contact time has the highest impact on dye removal in both algal species. The highest removal values were obtained in the case of dried U. fasciata, which achieved impressive removal percentages that reached 100% for RB195 and RB5 and fresh P. capillacea which had high removal percentages of 91.11, 94.85 and 97.13% for RR195, RB19, and RB5 dyes, respectively, after 8 h. Our results revealed that the used algal species were highly significant in the biosorption of most used dyes.