OIL AND GAS PRODUCED WATERS VERSUS COMMERCIAL DUST SUPPRESSANTS APPLIED TO GRAVEL ROADS:AIR QUALITY IMPACTS

Oil and gas produced water (OGPW) is used as a less expensive dust suppressant for some gravel roads in the USA. OGPW efficacy as a dust suppressant was studied and did not prove to be better than untreated roads. However, the concentrations of trace and major elements in the dust generated from roads treated with dust suppressants have not been studied in detail. The aim of our study was to compare the quality of dust (represented in PM₁₀ and PM₁) generated from roads treated with commercial brines (calcium chloride) or OGPW to dust from untreated roads. Three OGPW and a calcium chloride were used to treat samples of road aggregate, which were then tumbled using rotary drum in a bench-scale experiment. PM₁₀ and PM₁ generated from the tests were collected and measured for radioactivity (radium 228 and 226 and trace elements including: Al, As, Ba, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Sr, and Zn. Trace elements were measured by ICP-AES and radium activity was measured using Canberra small-anode germanium (SAGe) gamma spectrometer. Results show that mean values of Al, As, Cr, Fe, K, Mn were highest in samples, followed by OGPW, and commercial brines, respectively. However, Cu and Ba were highest in dust collected from roads treated with commercial brines than each of untreated and OGPW. OGPW was higher than untreated samples in Sr. Relatively high Sr and Ba results in OGPW could indicate high Ra activity.