ABSTRACT
Because of the increased amount of cobalt and Congo red dye effluents attributable to the industrial operations, the capacity of Enteromorpha intestinalis biomass as a sustainable source to achieve significant biosorption percent for both pollutants from dual solution was assessed. A fifty batch FCCCD experiments for biosorption of cobalt ions and Congo red dye were performed. The complete removal of Congo red dye was obtained at 36th run using an initial pH value of 10, 1.0 g/L of Enteromorpha intestinalis biomass, 100 and 200 mg/L of Congo red and cobalt for a 20-min incubation time. Meanwhile, a cobalt removal percent of 85.22 was obtained at 35th run using a neutral pH of 7.0, 3.0 g/L of algal biomass, 150 and 120 mg/L of Congo red, and cobalt for a 60-min incubation time. For further illustration and to interpret how the biosorption mechanism was performed, FTIR analysis was conducted to inspect the role of each active group in the biosorption process, it can be inferred that -OH, C-H, C=O, O-SO3- and C-O-C groups were mainly responsible for Co2+ adsorption of from aqueous dual solution. Also, scan electron microscope revealed the appearance of new shiny particles biosorbed on E. intestinalis surface after the biosorption process. EDS analysis proved the presence of Co2+ on the algal surface after the biosorption process.
ABSTRACT
This study characterized the extruded polymeric substances (EPS) secreted from Synechococcus mundulus cultures under the effect of 2-KGy gamma irradiation dose. The EPS demonstrated seven monosaccharides, two uronic acids and several chemical functional groups: O-H, N-H, =C-H, C=C, C=O, COO-, O-SO3, C-O-C and a newly formed peak at 1593 cm-1 (secondary imide). The roughness of EPS was 96.71 nm and only 28.4% total loss in weight was observed at 800 °C with a high degree of crystallinity quantified as CIDSC (0.722) and CIXRD (0.718). Preliminary comparative analyses of EPS exhibited high protein content in the radiologically modified (R-EPS) than control (C-EPS). Modified EPS were characterized with a high biosorption efficiency, which could be attributed to its high content of uronic acids, protein and sulphates as well as various saccharide monomers. Data revealed that 0.0213 mg L-1 h-1 is the maximum biosorption rate (SBRmax) of Cr(VI) for R-EPS, whereas 0.0204 mg L-1 h-1 SBRmax for the C-EPS respectively.