BIOSORPTION OF HEAVY METALS BY VARIOUS ORGANISMS (BACTERIA, ALGAE AND FUNGI)

Environmental bio-remediation of various heavy metal by the process biosorption, with help of living or dead bacteria, algae and fungi.

1. COURSE WORK SEMINAR ON BIOSORPTION OF HEAVY METALS BY VARIOUS ORGANISMS (BACTERIA, ALGAE AND FUNGI) Presented by Swayam Prakash Nanda Regd No:1981002011 Environmental Science Department of chemistry

2. Contents Introduction Objective Biosorption Mechanism Factors affecting Biosorption Organisms for biosorption Advantages and disadvantages Conclusion References

3. Heavy Metals Source Threshold limit value (mg/m3) Arsenic Pesticides 0.5 Cadmium Welding 0.2 Lead Paint 0.2 Manganese Fuel addition 5 Chromium Mines 1 Zinc Refineries 5 Copper Mining, chemical industry 1

4. Removal Technology Extraction Chemical precipitation Others Ion exchange Limitation • Tedious • Time consuming • Expensive. Biosorption A solution for eliminating the tedious heavy metal removing process SO AN ALTERNATIVE METHOD IS NECESSARY Electrodialysis Ultrafiltration

5. Objective Conventional methods for the removal of metal ions such as chemical precipitation and membrane filtration are extremely expensive. efficient at low concentrations of metal Biosorption and bioaccumulation are eco-friendly alternatives . natural materials like microbial biomass, agro-wastes, and industrial by-products have been suggested as potential biosorbents for heavy metal removal.

6. Biosorption Biosorption can be defined as a simple metabolically passive physicochemical process involved in the binding of metals ions ( biosorbate ) to the surface of the biosorbent which is of biological origin. Biological removal includes the use of microorganisms, plant-derived materials, agriculture or industrial wastes, biopolymers, and so on . Microorganisms (live and dead) and other industrial and agriculture byproducts can be used as biosorbents for the process of biosorption . Biosorption can remove contaminants even in dilute concentrations and has special relevance with respect to heavy metal removal owing to toxicity at ppb levels. Biosorption Sorbent Sorbate

7. The metal biosorption process involves a two-step process. In the first step metal ions are adsorbed to the cell surface by interactions between metals and functional groups displayed on the cell surface. In second step due to active biosorption metals penetrates into the cell wall. Continued….. biosorption is a metabolically passive process , it does not require energy, and the amount of contaminants a sorbent can remove is dependent on kinetic equilibrium and the composition of the sorbents cellular surface. Contaminants are adsorbed onto the cellular structure. Bioaccumulation is an active metabolic process driven by energy from a living organism and requires respiration . Both bioaccumulation and biosorption occur naturally in all living organisms however, in a controlled experiment conducted on living and dead strains of bacillus sphaericus it was found that the biosorption of chromium ions was 13–20% higher in dead cells than living cells . In terms of environmental remediation, biosorption is preferable to bioaccumulation because it occurs at a faster rate and can produce higher concentrations. Since metals are bound onto the cellular surface, biosorption is a reversible process whereas bioaccumulation is only partially reversible .

8. Mechanism

9. Types of mechanism Biosorption mechanism Metabolism dependant Non metabolism dependant Transport across cell membrane Precipitation Physical adsorption Ion exchange complexion

10. Types of mechanism Biosorption mechanism Intracellular Accumulation Cell surface accumulation/precipitation Extracellular accumulation/precipitation Transport across cell membrane complexion Physical adsorption Precipitation Transport across cell membrane is common to both type of mechanisms intracellular and metabolism dependent.

11. Factors affecting Biosorption Effect of pH increase in pH from 1 to 4 increased the biosorption of Cr (VI) from wastewaters by  Saccharomyces cerevisiae   biomass. biosorption of Cr by pretreated   Aspergillus niger  the optimum pH was found to be 3. increase in pH from 2.0 to 4.5 increased the biosorption of Cd by  Rhizopus cohnii   biomass. Effect of temperature 25 to 40°C is the optimum temperature for biosorption . Initial metal concentration The biosorption capacity of the biosorbent increases initially with the increase in metal ion concentration and then reaches a saturation value. Effect of biosorbent dose Effect of contact time Effect of agitation speed: The optimum speed of agitation for the biosorption of Cd and Zn by  Aspergillus niger  was found to be 120  rpm.

12. Algae as Biosorbents Because of their large surface area and high binding affinity they have been reported to effectively remove metals from waste water. High uptake capacities, similar to commercial ion-exchange resins and their availability is nearly unlimited amounts from the ocean Algae Optimum pH range Adsorbed metals Laminaria japonica 4.3-6.5 Cd 2 +, Cu 2 +, Ni 2 + and Zn 2 +. Chlamydomonas reinhardtii 6 Copper and lead Oedogonium sp. 5 Cu, Co, Cr, Fe, Hg, Ni, Zn, and U. Ulothrix cylindricum 6 As(III) Parvathy et al.2016

13. Fungi as Biosorbents Economical and constant supply source of biomass to remove metal ions from waste water • Can easily grow in substantial amounts using unsophiscated fermentation techniques • Can also easily grow using inexpensive growth media Fungi pH range Metal Adsorbed Fungalia trogii 6 Hg 2 +, Cd 2 + and Zn 2 + Trametes Versicolor 6 Cu 2 +, Pb and Zn 2 +, Rhizopuscohnii 4.5 - 6.5 Cadmium Parvathy et al.2016

14. Bacteria as Biosorbents The bacterial cell wall is the first effective compartment for adsorbing heavy metal particles because it contains many anionic functional groups, capable of binding to heavy metals, such as peptidoglycan, teichoic acids, phospholipids and lipopolysaccharides Bacteria pH range Metals adsorbed Tsukamurella paurometabola 6 Cd 2 + and Zn 2 + Thermophilic bacteria 2.3 strontium Bacillus sp. 9 cadmium and nickel Geobacillus toebii 3-6 Cd 2 +, Cu 2 +, Ni 2 +, Zn 2 + and Mn 2 + Parvathy et al.2016

15. Algae Chlorella vulgaris removes Cd(II) with an efficiency at 96.8% (dead) and 95.2(alive) Bacteria Bacillus subtilis was most efficient in Zn removal with an efficiency 99.2(dead) and 96.3(alive) Fungus Phanerochaete chrysosporium removes 64.25 % Cr and 57% Ni

16. Advantages Very rapid and takes place between a few minutes to a few hours. A wider range of operating conditions such as pH, temperature and metal concentration is possible. No aseptic conditions are required. Low operating cost High efficiency Minimisation of chemical and/or biological sludge . No additional nutrient requirement. Regeneration of biosorbent . Possibility of metal recovery.

17. Disadvantages Early saturation Potential for biological process improvement is limited Re-generation of biosorbent materials

18. A useful and effective alternative against the conventional system From studies it is inferred that the microbial cells retain the activity in an optimum pH range and depend on other factors like concentration of metal ion and biomass . This will help in identifying the suitable biosorbent for biosorption process . Even though this is a cumbersome task, engineers are actively working to develop a biosorption optimization by modelling More research on recombinant organism should be done for better result in biosorption . Conclusion

19. Referances Sri Lakshmi Ramya Krishna Kanamarlapudi , Vinay Kumar Chintalpudi and Sudhamani Muddada 2018 Application of Biosorption for Removal of Heavy Metals from Wastewater, Biosorption . F Veglio , Removal of Metal Ions by Biosorption . R. Flouty , G. Estephane / Journal of Environmental Management 111 (2012) 106e114 . M. Akbari et al. / Journal of Environmental Chemical Engineering (2014) R. Black et al. / Journal of Environmental Chemical Engineering 2 (2014) 1663–1671 effluent . Heavy metal biosorption by white rot fungi, by Ulkii Yetis . Biosorption of uranium and heavy metals using some local fungi isolated from phosphatic fertilizers, by Amany