Bioremediation

Bioremediation is the deliberate use of microorganisms or plants to clean up environmental pollution - treating contaminated wastewater, industrial waste and solid waste, and specifically targeting the removal of oil, petrochemical residues, pesticides or heavy metals from polluted soil or groundwater. Compared with conventional physical or chemical remediation methods, bioremediation is frequently both cheaper and more environmentally sustainable, and it can often deal effectively with contaminant concentrations too low for physical/chemical methods to economically target at all. In practice, bioremediation strategies fall into a few recognisable approaches: using naturally occurring (indigenous) microbial populations already present at a site as an indicator of contamination and a starting point for cleanup; deliberately adding adapted or purpose-designed microbial inoculants to boost degradation; and using plants directly for remediation, sometimes described as a 'green technology' approach. Several of these strategies have their own specific names worth knowing individually: phytoremediation (plants used to remediate environmental pollutants directly), mycoremediation (fungi used for the same purpose), bioventing (increasing oxygen/air flow through contaminated soil to accelerate microbial degradation of pollutants), bioleaching (using microorganisms in solution to recover metal pollutants from contaminated sites or ore), bioaugmentation (adding selected microbes specifically to speed up an ongoing degradation process), composting (using microbes to convert solid waste into nutrient-rich manure for plant growth), rhizofiltration (uptake of metals, or degradation of organic pollutants, by microorganisms living in the root zone/rhizosphere), and rhizostimulation (boosting plant growth in the rhizosphere by improving growing conditions or reducing toxic material levels there). Bioremediation does have real, practical limits, though: it can only ever br …