Assessment of chromium bioaccumulation in Pseudokirchneriella subcapitata (Korshikov) Hindak by the Central Composite Design (CCD) and Response Surface Methodology (RSM)

Abstract

The effects of chromium bioaccumulation in Pseudokirchneriella subcapitata were evaluated by Central Composite Design (CCD), factorial 2 2 and Response Surface Methodology (RSM). All the models of regression generated by CCD were highly significant, with R 2 between 77 and 88%, which is the percentual variability in the response that the model can account for. This is indicative of a satisfactory representation of the process models whose data can be used for simulations of response. The maximum shrinkage biovolume presented 28–69% reduction compared to controls. Results from this study suggest that the smaller algal cells amplify metal binding sites, leading to an increased bioaccumulation and a consequential increased capacity to accumulate chromium. Nevertheless, the absorption capacity decreases for more elevated chromium concentrations and for longer exposure. Keywords : Algae, Biovolume, Central Composite Design, Metal, Selenastrum capricornutum .