Study On The Mechanism Of Chlorophenols Degraded By Ultrasound/Iron And The Structure-Activity Relationship

In this study, the degradation efficiency of pentachlorophenol (PCP) by ultrasound in the presence of iron was reported. The major affecting factors on PCP degradation such as iron loading, initial pH value of solution, initial concentration of PCP were studied. This study focus on the synergistic mechanism of the enhanced degradation of PCP by ultrasound in the presence of iron and the degradation pathway of PCP. At the same time, the structure-property relationship of chlorophenols was also studied.Ultrasound combined with elemental iron (US/Fe0) was effective in oxidizing organic contaminants in water. The sonolysis degradation of pentachlorophenol (PCP) was significantly enhanced with the addition of elemental iron. The effect of pH, iron loading and initial PCP concentration on the degradation of PCP by elemental iron combined with ultrasound radiation was investigated. It was shown that the degradation of PCP was enhanced by ultrasound and the degradation appeared to be a first order reaction. With the pH range of 2~11, iron loading range of 0.25~1.5gL?1 and initial dye concentration of 5~200 mgL?1, the PCP removal rate decreased with the increasing pH or initial PCP concentration, but increased with the increase of iron loading. With iron loading range of 1.5~3.0gL?1, the PCP removal rate decreased with the increase of iron loading. Under the same condition, the destruction of chlorophenols (CPs) follows an apparent first-order kinetic and the rate constant increased with the increased number of Cl on the benzene ring: 2-CP<2,4-DCP<2,4,5-TCP<2,3,4,6-TeCP