Biochar Water Treatment
research to functionalized biochars to remove arsenic and fluoride
Caminos de Agua is currently in the trial testing stages of utilizing biochar for arsenic and fluoride remediation of contaminated groundwater resources in northern Guanajuato (with global applications).
A colaboration with Aqueous Solutions, born out of Executive Director Dylan Terrell´s participation in a January 2016 workshop organized in Thailand, has exponentially moved forward our research in biochar application for fluoride removal.
Our work on fluoride remediation is much further along than our arsenic research and is nearly ready for small-scale pilots in real community homes. Our fluoride system utilizes “bone char” – biochar made from animal bones – and has proven highly effective in removing fluoride from contaminated groundwater. Fluoride is aggressively “attracted” to calcium, which is why it is most often found bound with calcium in nature. That is also why fluoride accumulates in the teeth, bones, and even the pineal gland in the brain – all areas high in calcium. Thus, the high calcium carbonate content in bone char targets fluoride by exchanging the calcium ions in the bone char with the fluoride ions in the contaminated water – essentially locking up the fluoride in the bone char and not allowing it to pass through into the drinking water supply. This all happens through a combination of chemical adsorption processes known as ion-exchange and contact precipitation.
What is biochar?
Biochar is a sustainability strategy for food, climate and environmental management. Similar to charcoal, biochar is made by heating biomass in an oxygen-starved environment, with usable bioenergy as a co-product. Based on recently discovered agricultural practices of ancient Amazonia, and supported by solid science, biochar has been demonstrated in field trials to increase yields while reducing agrochemical inputs, shorten harvest cycles, enhance pest resistance and improve drought tolerance. Its stable carbon matrix resists biological decay, so biochar soils are persistently fertile. And since its sequestered carbon originated in the atmosphere (through photosynthesis), biochar actually reduces atmospheric carbon, making it a “carbon negative” technology for addressing climate change. Biochar can also be used as filtration media (similar to activated carbon) and to address other environmental management challenges.