Remediation

Bioremediation

Bioremediation is an umbrella term for a group of related concepts and processes for decontaminating a location, or even the environment in general.

Types of bioremediation can be split two ways: by prefix and by affix. If you change the prefix you get things like: phytoremediation, mycoremediation, bacteriremediation and zooremediation. If you change the suffix you get things like: Bioaccumulation and Biotransformation. 

Phytoremediation

Phytoremediation refers to bioremediation that only or primarily involves plants.

Mycoremediation

Bioaccumulation

Bioaccumulation occurs when an organism accumulates, adsorbs, or absorbs a substance into or onto its body, removing it from the general environment. The terms: Bioabsorption, bioextraction, and biomagnification are related terms that are sometimes used interchangeably with Bioaccumulation.

Biotransformation

Biotransformation is a biochemical process that modifes an element, a chemical compound, or a mixture of things in some way.

In terms. of Bioremediation, the three main types of biotransformation are: biodegradation, biostabilization, and biovolatilization.

Biodegradation

Biodegradation refers to a lifeform breaking down substances at a chemical level. Effectively eliminating certain chemicals while creating others as byproducts.

Stabilization

Biostabilization is the act of an organism or biological materials altering the chemical state of a substance such that it is more stable. This generally means, decreases in the risk posed by a waste by converting the contaminant into a less soluble, immobile, bioavailable, and/or toxic form. It is a type of Biotransformation. The inverse of biostabilization is biovolatilization.

Volatilization

Biovolatilization is the act of an organism or biological materials altering the chemical state of a substance such that it is more volatile. This generally means, increases in the risk posed by a waste by converting the contaminant into a more soluble, immobile, bioavailable, and/or toxic form. It is a type of Biotransformation. The inverse of biovolatilization is biostabilization.

Chemical Remediation

Chelation Therapy

Physical Remediation

Many toxins aren’t stable. Radioactive substances decay over time into different elements releasing radiation in the process. Some complex chemicals are unstable enough to decay into other chemicals over time. Most chemicals and elements, even relatively stable ones, will change into something else given enough time. Often a substance will change into multiple different substances at multiple points in time.

Dig and Dump

One of the oldest and historically cheapest methods to “remediate” a plot of land was to dig the contaminated soil up, haul it to a hazardous waste dump, and refill the area with fresh uncontaminated soil. This has met with several problems: 1. It doesn’t fix the pollution, it only moves it elsewhere. 2. The rising costs of hauling and dumping the soil. 3. The shrinking supply and rising costs of uncontaminated soil.

Other Key Concepts

Rhizosphere

The Rhizosphere is the zone of chemical, biological, and physical influence generated by root growth and activity. The concept usually pertains to the soil-root interface but is sometimes extrapolated to other media-root interfaces.(2)

Bioreactors

A Bioreactor is an artificial containter, device, or enclosure that supports biological organisms. Generally this also refers to having organisms or biologocial componenets carry out a chemical reaction.

     Waste Water Treatment

A common usage of a bioreactor is in waste water treatment. Many modern sewage treatment plants have one or more bioreactors that contain microorganisms that biodegrade the waste water.

     Compost Tea

Compost tea is made by a simple bioreactor that can be set up with fairly common materials, which propagates the growth of aerobic microorganisms. The liquid substance that is produced is then applied to home gardens and farms to promote soil health. This can improve several properties of the soil including promoting plant growth and disease resistance. (3, 4)

Fate of transport

Fate of transport refers to where a substance ends up and what it form its in. In terms of the environment in general transport means where in the environment the substance ends up after natural forces have moved it. In organisms, it refers to where in the organism,  the substance ends up. In Human health it refers to what part or parts of the body a toxin ends up in and in what form.

In Situ / Ex Situ

In situ can refer to where a clean up or remediation of a polluted site is performed using and stimulating the natural processes in the soil, contrary to ex situ where contaminated soil is excavated and cleaned elsewhere, off site.

Monoculture and Polyculture