Technology Description

A technique has been developed through which R. tropici-derived biopolymer can be produced in an aerobic bioreactor. The biopolymer is separated from the growth media and derivatized in order to produce a nonreactive (non-crosslinking) material. During this process, the biopolymer can also be functionalized to improve its adsorption of heavy metals. This nonreactive material can then be transported as a low-density, dry solid and applied to the soil using one of two methods. The first method involves mixing the dry biopolymer with water at the site of use, producing a viscous liquid, or gel, which is applied to the soil surface. The second method involves mixing the dry biopolymer into the soil, then applying water. Using either application method, the biopolymer will form a gel within the soil matrix when wetted. With the soil acting as a buffer, the ionic character of the biopolymer salt is neutralized and the biopolymer can begin reacting with itself and the metal constituents of the soil matrix. The reactive, crosslinked biopolymer has a larger molecular weight, a reduced water affinity, and links together the individual soil particles within the biopolymer matrix. The individual soil particles of the amended soil have greatly reduced mobility, significantly reduced hydraulic conductivity, and compressive strength equal to that produced by synthetic polymer amendments. This change in the physical form of the soil on a particle level will result in increased soil strength, reduced air transport, and decreased soil erosion.