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 °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.