Comparative Study for Biosorption of Heavy Metals from Synthetic Wastewater by Different Types of Marine Algae

Pollution by heavy metal ions is one of the major environmental problems in many countries. In this study, four different species of dried marine macroalgae, Ulva lactuca, Jania rubens, Pterocladia capillacea and Colpomenia sinosa were used for the removal of toxic heavy metal ions Pb+2, Cd+2 and Ni+2 from synthetic wastewater. In general, the highest efficiency of metal ion bioremoval was recorded for red alga J. rubens followed by C. sinosa and the lowest one was recorded for U. lactuca, with mean removal values of 91%, 89% and 85%, respectively. The effect of several parameters such as contact time, algal dose, effect of pH, and initial concentration of metal ions on the adsorption process was estimated. The optimum adsorption was found to occur at pH 5.0, contact time 60 min, adsorbent dose 20 g/L and initial concentration 40 mg/L. This work confirms the potential use of red macroalga J. rubens as an inexpensive and efficient alternative technology, for sequestering heavy metal ions from wastewater.