Can our soils help us clean our waste water? You Decide!

One of the items we hear a lot is that septic sand mounds are an eyesore. Instead of a large grassed mound, maybe a beautiful and functional wetland cell would provide a more aesthetically pleasing solution, as well as a habitat for our backyard friends.

Soils are so amazing…

There are more microorganisms in a handful of soil than there are people on earth
It takes 500 years to produce just under an inch of topsoil, this is the most productive layer of soil.
Soil is a living system
Soil acts as a filter for underground water, filtering out pollutants
Approximately 10% of the world’s carbon dioxide emissions are stored in soil
Soil consists of 45% minerals, 25% water, 25% air & 5% organic matter

If plants and soils can do this…

Phytoremediation, or using plants to remove toxic metals and contaminants, is accomplished by four different techniques. The first Rhizofiltration, uses plants to clean water system, such as septic. Second is Phytostabilization, which immobilizes the pollutant rather than removing the pollutant from the soil. Third, Phytovolatization, occurs when plants extract contaminants and release them in to the air. Fourth is Phytoextraction, where metals are translocated and accumulated in harvestable shoots and removed for incineration of plant material and the contaminants. Lastly, Phytodegradation occurs when the plant uptakes the contaminants and breaks down the pollutant into less severe contaminants.

One well known disaster site, Chernobyl, has had multiple instances of hyperaccumulators (plants that complete phytoremediation) and bioremediation. In Germany, France, Sweden and Russia, months after the meltdown, fresh mushrooms contained 4 times the acceptable rates of Cesium traceable to Chernobyl. Dried mushrooms showed 20 times the allowed amount. Mushrooms, in the kingdom Fungi, acquire food by dissolving the nutrients in soils, including metals and other contaminants. Twenty-two species of mushrooms were found to have Strontium-90 and Cesium-137 just a few months after the disaster. Sunflower, another hyperaccumulator, are being used at Japan’s Fukushima nuclear disaster site after the experimentation at Chernobyl showed great result. The plants harvestable biomass is easier to incinerate, then a non-renewable containment soil, which is generally either stored at a nuclear waste facility or incinerated for some contaminant.

…can wetland cells treat our sewage more effectively and look better in our backyards? (YES!!)

Further Readings

On-Site Sewage Facilities

https://ossf.tamu.edu/constructed-wetland/

Why are wetlands so important?

https://www.epa.gov/wetlands/why-are-wetlands-important

Phytoremediation Studies

http://2013.igem.org/Team:TU-Munich/Project/Phytoremediation

Healthy Soil Microbes, Healthy People

https://www.theatlantic.com/health/archive/2013/06/healthy-soil-microbes-healthy-people/276710/

Using Plants to Clean Soil

http://www.mhhe.com/biosci/pae/botany/botany_map/articles/article_10.html