Comparison of Biosorption of Heavy Metal Zinc by four different Microbial Biomas (Activated sludge) in Industerial Waste Water in order to Biological Refinement

Subject Areas : Environmental Microbiology

Azita Khosravan ¹ , Javid Amini ² , Samira Sarsalary ³ , Elham Rohanian ⁴

1 - International Center for Science, High Technology & Environmental sciences, Kerman, Iran
2 - Microbiology Department Education Research Center Kerman, Iran
3 - Pooria-taeem Company, Kerman, Iran
4 - Borna-moeen Company, Kerman, Iran

Received: 2009-04-14 Accepted : 2009-05-15 Published : 2009-04-01

Keywords: Zinc, Biosorption, Activated sludge, Microbial Biomass,

Abstract :

Background and objectives: Industrial and agricultural activities have led to a substantial release of toxic heavy metals in the environment, which can constitute a major hazard for the ecosystem and human health.. Today, the use of microbial biomass for removal of heavy metals from aqueous solutions is gaining increasing attention. This study aims to evaluate the ability of the adsorption of heavy metal Zinc by four different biomasses (activated sludge of the systems of waste water refining, non-alcohlic carbonated soda industries, milk, herbal oil, and poultry slaughterhouse) and to determine the optimum conditions of pH for eliminating this metal from industrial waste water. Materials and methods: The different values of this industries activated sludge added to 250mil Zinc solution of specific concentration. Then in different times, we took sample of the result solution and measuring the concentration of Zinc by atomic absorption method.This experimental repeated by solutions that their pH adjusted to 4                         0.2, 5 0.2 and 6.5 0.2. Results: Study of the results delineated that 30mil activated sludge of factories, non-alcohlic carbonated soda, Vegetable oil, Milk and poultry slaughterhouse within 150 min, about 82%, 33.4%, 48.9% and 51.5% of the initial concentration of Zinc in the solution was reduced, respectively. The comparison of Zinc absorption ability of active sludge in each industry in different pH showed that all of the mentioned industries sludge with pH=6.5 had the most ability in Zinc absorption. Conclusion: We can use this material to eliminate Zinc from waste water and their refinement, considering the low cost of the sludge substrast and also is availability. So adjusting the primary pH of solution, the out put of Zinc removal from solution in waste water treatment can be increased.