Treatment of Azole-Containing Industrial Wastewater by the Fenton Process

Some semiconductor fabrication processes generate high-strength wastewater that may contain high concentrations of azoles, amines, hydrogen peroxide, organic, and inorganic co-contaminants, making the treatment of this wastewater challenging. In this study, the Fenton process was utilized for the treatment of 53 mM pyrazole and 34 mM 2-(2-aminoethoxy) ethanol (known as diglycolamine, DGA) in a lab-prepared aqueous mixture containing 3.5 M hydrogen peroxide and 16 mM inorganic fluoride. The effects of operational variables for the Fenton process, such as temperature (10, 18, or 25 degrees C), iron dosing (32.3, 37.3, or 74.5 mM), and pH (2.5, 3.0, or 3.5), on the degradation rates were investigated. The chosen variables were then used to treat wastewater from a semiconductor fabrication facility. The Fenton process was effective in treating both the lab-prepared mixture and semiconductor industrial wastewater. The degradation of pyrazole and DGA yielded a range of byproducts including inorganic ions and organic acids.