How Plants and Microorganisms Can Clean up the Mess We Make

Avoiding pollution in the first place would be best. But as we transition to a post-carbon future, biological solutions can help us find a path forward.

Close-up of a person standing in the forest holding a handful of moss, Russia
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Bioremediation is a fascinating area to explore if you are interested in ecology, ecosystems, and nature restoration. This is the process by which we use plants, bacteria, or fungi to clean up contaminated air, soil, or water. There is a wide range of natural processes that can be co-opted to clean up the mess we make.

We all know that human development often comes at a cost to the environment. Many landscapes and ecosystems have been severely degraded by human activity—and polluted by industry and poor waste management. But the good news is that bioremediation techniques can be utilized to remove or reduce pollutants and "fix" ecosystems that have already been damaged.

Here are a few examples of bioremediation, which serve as illustrations of what can be done.

Cleaning the Air

The first interesting thing to look at is biological carbon capture. The Algoland carbon capture project is one example of how the biological process of photosynthesis can be harnessed to capture carbon at a factory level.

Microalgae are being sought as alluring biofactories for the sequestration of CO2 and simultaneous production of renewable biofuels, food, animal and aquaculture feed products, and other value-added products such as cosmetics, nutraceuticals, pharmaceuticals, bio-fertilizers, bioactive substances. At Drax power station in the UK, for example, they are looking at turning CO2 into food for fish. Seaweed is also being explored for its potential to sequester carbon in biorefinery.

Bioremediation also involves using microorganisms to remove other atmospheric pollution. Biofiltration is now used in place of chemical scrubbing in many factories to remove volatile organic compounds from industrial emissions. Microorganisms living in a replaceable culture medium degrade contaminants into carbon dioxide, water, or salts. This is the only biological technique currently available to remediate airborne pollutants.

A range of enzymatic processes can also be used within industrial processes to reduce the number of harmful pollutants within a factory system. (Enzymes have also been discovered which could help to combat other forms of waste—there is a plastic-eating enzyme, for example.)

In the wider environment—in cities and around industrial sites, there are also other biological solutions that can help clean the air. Planting more trees can help to reduce air pollution. But mosses have been shown to be effective tools in measuring atmospheric pollution. And certain moss species are considerably more capable of accumulating heavy metals than tree leaves..

Nitrogen oxide, ozone, and particulate matter are absorbed by mosses, offsetting many tonnes of CO2 equivalents per year. This has led to the invention of the "City Tree"—a moss filter used as a "biotech fine dust filter for urban spaces," already employed in Norway, France, Germany, Belgium, the UK, Macedonia, and Hong Kong. One CityTree is said to be equivalent to 275 trees—not only sequestering carbon but also ridding city air of other harmful substances. Placement of these structures close to industrial sites and around cities will help clean up the air that we breathe.

Cleaning Water

Bioremediation using microorganisms is being increasingly used in the decontamination of polluted water using bioreactors. And soil and groundwater can be decontaminated using in-situ bioremediation methods using bacteria and fungi. Microfauna such as nematodes and protozoa are also being investigated for their ecological functions and potential for bioremediation of contaminated soils.

Water can also be cleaned through the agency of reed bed filtration systems and constructed wetland systems. Vegetated swales and other hydrological landscape management features can take runoff from hard surfaces like roads and prevent contamination of surrounding ecosystems. Using plants for bioremediation is known as phytoremediation.

Cleaning Soil

Certain mushrooms can also be used in ecosystem restoration and bioremediation. Using mushrooms for remediation is often referred to as mycoremediation. Many reports have been published to emphasize the role of mushrooms in the bioremediation of wastes by the process of biodegradation, biosorption, and bioconversion.

Hyperaccumulator plants can also be grown on polluted sites (phytoremediation) to extract heavy metals and other pollutants from the soil. By recognizing the ability of certain specific plants to accumulate toxic substances, landscapes that have been polluted can be restored.

Nature is a wonderful thing. Often, it can deliver all the solutions we need to repair the damage humanity is doing and has done. While there is still a lot of work to be done, it is clear that the biological solutions offer hope that we can clean up some of the mess we have made.

Of course, working out how we can avoid damaging and degrading natural environments in the first place is of vital importance. We cannot become complacent in reducing emissions and pollution. But as we transition to a post-carbon future, biological solutions can certainly help us find a pathway forward.

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  7. (Akinyele et al. [2012], Kulshreshtha et al. [2013a]; Kumhomkul and Panich-pat [2013]; Lamrood and Ralegankar [2013]).