Assessment of the metal removal capability of two capsulated Cyanobacteria, Cyanospira capsulata and Nostoc PCC7936

Experiments were conducted using two capsulated, exopolysaccharide-producing cyanobacteria (namely Cyanospira capsulata and Nostoc PCC 7936) to evaluate their metal removal performance. These experiments utilized copper as a model metal. These experiments were implemented using sole cyanobacterial biomass suspended in distilled water and confined into small dialysis tubings. Evidence from these tests showed that C. capsulata biomass provided the best efficiency for removal of metals from solution. Data from both of the tested microorganisms were found to fit well with the Langmuir sorption isotherm. The optimal pH value for treatment was found to fall in the range of 6.1-6.2. Factors that acted to reduce the copper removal performance of the two microorganisms are discussed.