GLUTARALDEHYDE REMOVAL FROM FLOWBACK AND PRODUCED WATERS USING PHOTOLYSIS

Glutaraldehyde (GA) has been used extensively as a biocide in hydraulic fracturing fluids leading to the contamination of the compound in flowback and produced waters. Photolysis of GA in water was performed under UV irradiation using monochromatic lamps with a wavelength of 254 nm. The results indicated that photolysis of GA followed pseudo-first order kinetics. GA can be photolyzed by UV at all studied conditions; however, the degradation rates of GA were different at different light intensities, pHs, initial GA concentrations and salt concentrations. The degradation rate of GA increased with increasing incident light intensity and decreasing pH. Increasing in initial GA concentration resulted in decreasing rate of GA. At lower salt concentrations, notable retardation of GA degradation rate was observed. Quenching experiments were also conducted to further explore the mechanisms of GA photolysis. Higher molecular weight compounds were identified as the main photolytic byproducts.