Background: Industrial effluents loaded with heavy metals are a cause of seirous hazards to human and other forms of life. However, conventional methods such as precipitation, ion exchange, electrodialysis, etc. used for the removal of heavy metals from wastewater, are often cost prohibitive having inadequate efficiencies at low metal ion concentration. Biosorption can be considered as an alternative technology which has been proved as more efficient and economical for the removal of heavy metals from the industrial wastewater. This study aimed to review the use of some natural biosorbents for removing toxic heavy metals from water and wastewater.

Materials and Methods: In this research different biosorbents were used. Biosorbents were ground and sieved into size 250-500 µm. The samples were analyzed using various methods for the determination of metal ions concentration.

Results: The biosorption of metals such as copper, zinc, lead, iron and cadmium by coffee beans showed that all metals were adsorbed at low pH 3-5. The absorption capacity of egg shell (160 mg/g) for Cr (III) was reported.

Conclusion: The recent survey shows the potential use of natural products such as tea leaves, tea waste, rice husk, orange peel, coffee seeds, wheat stem, egg sell, etc., as biosorbents for removing heavy metals from aqueous solutions. Mathematical modelings are also helpful for biosorption process optimization.