Modelling of butylated hydroxytoluene (BHT) transport in water in PE-HD pipe including chemical reaction of BHT oxidation

Abstract

This paper presents laboratory and modelling studies of antioxidant butylated hydroxytoluene leaching from a water supply PE-HD pipe for laminar and turbulent flow. The reaction of BHT oxidation to BHT-OH was included in our calculations. Required input data, initial and boundary conditions were based on laboratory measurements performed for a new PE-HD pipe. Laboratory measurements covered tests of BHT content and homogeneity in pipe material as well as measurements of BHT concentration in water flowing inside the pipe loop with different velocities. The BHT content of the PE-HD pipe and its concentration in water were determined by GC-MS method. Modelling calculations of BHT concentration in water for two different types of flow were performed using the commercial CDF software Fluent (Ansys Inc.). Non-homogeneous BHT distribution in pipe material and leaching of the antioxidant to the water were observed during laboratory tests. Numerical prediction of BHT concentration in water showed acceptable agreement between measured and calculated data. Nonetheless, the universality of the developed model is limited by the great diversity of available plastic pipe materials with various contents and technological amendments.