Salinity-fluctuation alters phycoremediation capacity of lead by Spirulina platensis

Abstract

Phycoremediation has emerged as a proven economical technique for removing heavy metals, including lead (Pb). However, the phycoremediation capacity of Pb by Spirulina platensis under different environmental condition (including salinity) has not yet been investigated. Hence, this study aims to examine the phycoremediation capacity of Pb by S. platensis at different levels of salinity. S. platensis was exposed to Pb (4 mg/L) at different levels of salinity (up to 30 ppt) for 12 days. The results indicated that salinity fluctuation was able to reduce phycoremediation capacity of Pb. The highest removal efficiency of Pb was observed in optimum salinity and decreased significantly both in lower and higher salinity treatments. Physiological disturbances in S. platensis were indicated by changes in functional groups and morphology. The morphology of Spirulina platensis both in lower and higher salinity treatments appeared to have changed its shape, resembling a disjointed thread with fading color.