Environmental impact of hydraulic fracturing in the United States tuberculosis, kidney disease, autoimmune disorders and airway disease such as asthma and bronchitis. Most of these debilitating and potentially fatal diseases are preventable with occupational control measures regarding respirable crystalline exposure. Hydraulic fracturing uses abundant amounts of sand in the process of fracturing as part of the hydraulic fluid. The fracturing fluid consists of a base fluid, proppant and chemical additives. The majority of proppant used in fracturing are made of silica (sand). Truck loads of sand are delivered to the sites, then loaded to sand movers that are then transferred to a blender that mixes the hydraulic fluid. The
Sol–gel process Sol–gel process In materials science, the sol–gel process is a method for producing solid materials from small molecules. The method is used for the fabrication of metal oxides, especially the oxides of silicon (Si) and titanium (Ti). The process involves conversion of monomers into a colloidal solution ("sol") that acts as the precursor for an integrated network (or "gel") of either discrete particles or network polymers. Typical precursors are metal alkoxides. In this chemical procedure, a "sol" (a colloidal solution) is formed that then gradually evolves towards the formation of a gel-like diphasic system containing both a liquid phase and