Since money is tight for these projects, the EPA and PRP's (Potentially Responsible Parties, but let's just call them "perps") should be happy to know that there is a lower cost method available to remediate heavy metal contamination in soils. Heavy metals are elements of high density (> 5 g/cc) and include Cd, Cu, Hg, Ni, Pb, and Zn. These metals are often left in the soil after manufacturing, mining, and disposal operations have moved on and can also be spread far and wide on the wind, especially from stack gases. They make it into the food chain via plants, and easily transform wholesome food into poison or ruin crops altogether. In some projects, activated carbon is used to sorb the heavy metals, but research has found that some less costly biochars do a better job.
|CONTAMINATION by luc borell|
With the loss to date of 1 billion acres of degraded, abandoned farmland, recovering that land is important for both the climate and public health. Estimates show the global activated carbon market to be growing exponentially due to environmental needs. Biochar made from animal manure, and then steam-activated, could satisfy 35% of worldwide granulated activated carbon (GAC) demand. It is cheaper than regular GAC and recycles another overloaded waste stream to useful ends. Other processes have used different biochar feedstocks and additives and proven helpful, as well, but manure's high phosphorus fraction seems to give it better heavy metal adsorption ability, according to Dr. Isabel Lima. Lead and mercury are adsorbed particularly well by phosphorus functional groups.
With energy companies like Shell dipping their toe into biochar production, there may be a better chance that their man Pruitt and the EPA will look into this solution.