EAI presents Cleantech Snapshots: a quick summary of some of the most interesting and innovative areas in clean technology that will drive the sustainability movement in future.
This snapshot focuses on Bioremediation. Within this page you will find
- An overview of Bioremediation
- It’s key components
- Types of bioremediation
- Stages involved
- Drawbacks
- Bioremediation Case studies
Overview
- Bioremediation is the use of biological organisms to remove pollutants from a range of media. It is fast replacing conventional processes for pollution control that use chemicals and other harmful synthetics
- Some examples of bioremediation include phytoremediation (using algae), bioleaching, use of bioreactor, composting, rhizofiltration, etc. Many organisms, prominent among them bacteria and algae, are used as bioremediation agents
- While bioremediation presents a sustainable avenue, there is need for significant research before it could become a large scale alternative to conventional pollution control methods
- Bioremediation is a cost-effective, sustainable, natural approach to cleaning up contaminated soil and groundwater through the use of biological agents such as bacteria, microbes, fungi and other organisms
- There are a number of cost/efficiency advantages to bioremediation, which can be employed in areas that are inaccessible without excavation
Bioremediation(Image source)
Key components
- Electron donor: Hydrogen which can be derived from a carbon source such as vegetable oil or lactate
- Electron acceptor: Respiring agent like oxygen, although many microorganisms are capable of using other agents such as nitrate, sulfate or even a chlorinated solvent
Types of bioremediation
- Biostimulation
- Bioaugmentation
- Intrinsic Bioremediation
Stages involved in bioremediation
- Compliance analysis: Requires examination of the contaminated site in light of the regulations that govern it and the actions that needs to be taken
- Site characterization: Involves analysis of the physical characteristics of the site, the source of pollutant(s), the nature of the contaminated soil or water, and the distribution and concentration of contaminants
- Feasibility of a possible bioremediation approach, usually involving assays of pollutant degradation carried out under controlled laboratory conditions, has to be determined. It is at this stage that the suitability of a bioremediation approach falls under severe scrutiny
- The fourth stage in a bioremediation project is the process of remediation itself, which may involve multiple steps, such as pretreatment, or anaerobic followed by aerobic treatment of contaminated soil or material, as discussed above. Monitoring systems are employed to evaluate the progress and extent of contaminant degradation or conversion
- The last stage of a bioremediation project involves final monitoring of the site for the presence of contaminants and closure of the project
Drawbacks
- Process is slow. Time required is in days to months
- Heavy metals are not removed
- It does not remove all quantities of contaminants
