Description |
In nature, boron is generally found as soluble salts. The high level of solubility of these salts leads to the wide distribution and dispersed concentration of boron in the Earth's crust. This dissertation addresses the capture and environmental sequestration of low levels (less than 20 ppm) of boron in water and wastewater streams. Sequestration combines removal of boron from the water with boron containment in a relatively stable state or form that is not readily re-solubilized into the aqueous environment. Often, boron removal techniques sufficiently capture boron from the primary water source, but produce waste regeneration streams. These streams require significant further treatments or specialized containments to keep the boron from being easily re-introduced into the environment. The research here presents a technique to capture and chelate boron as a stable ester integral with a polymeric matrix. This captured boron-polymeric material when adsorbed onto disposal solids, can be disengaged from the water using techniques of liquid solid separations. The chelated boron ultimately reports with the waste solids to a landfill disposal. Boron as a stable ester in this form is thermodynamically robust, and natural conditions of the landfill do not present sufficient driving force to liberate the boron from the ester complex. This keeps the boron in a sequestered form without the need for special treatments or environmental isolation. |