Keywords: algae, heavy metal, removal, bioremediation
Summary:The contaminations of heavy metals from industrial wastewater into natural water resources affect life significantly. Heavy metal ions can accumulate in the environment and into the food chain. Therefore, an efficient process capable on removing heavy metal from wastewater is essential and very important. Old treatment technologies used for heavy metal removal have several disadvantages such as high cost, high chemical requirement and the production of large volumes of residual sludge. Bio-sorption processes are new alternatives that can be used effectively for heavy metal removal. Biological processes including algae as sorbent was proposed as an alternative for heavy metals removal from industrial wastewater due to its low cost, low sludge production, high efficiency, and it considered environmental friendly In the present study batch bio-sorption of Nickel, Copper, and Aluminum ions from Qatari industrial wastewater using Spirulina green blue green algae (cyanobacteria) was studied. The effect of initial metal ion concentrations, bio-sorbent dosage, temperature and pH on heavy metal removals efficiencies were reported. Moreover, the efficiency of heavy metal removal from synthesis wastewater compared to real industrial wastewater were investigated. Both live and dead algae were used in the study the performance of each were reported and compared. Figure 1 shows that algae can remove heavy metal ions from wastewater under all the studied concentration. The efficiency of heavy metal removal by bio-sorption increasing by increasing the heavy metal ion concentration in the wastewater suggesting high capacity for metals uptake. It was also observed that the number of binding sites available on microalgae for complexation of ions are extremely high suggesting high electrostatic interactions between the biomass and ions. For the studied heavy metals, the optimum biomass dosage and pH ranged from 0.5 to 1.2 g/L and 5-6.8, respectively. The maximum metal uptake by blue green algae was 19.82 mg/g of Aluminum, 3.24 mg/g of Nickel, and 13.08 mg/g of Copper. Results suggest that bio-sorption can be successfully employed as heavy metal removal technology.