Removal Of O-Chlorophenol And Methyl Orange By Sulfate Radicals

The advanced oxidation process based on sulfate radicals received attentions because of its unique advantages.It had a large number of applications in the field of waste water treatment, groundwater treatment and soil restoration. In this study, two techniques of sulfate radicals generation:heat activation of potassium persulfate and cobalt catalytic activation of potassium hydrogen sulfate. The two methods were applied to degrading o-chlorophenol. influences of factors including...were explored. The respective reaction mechanisms were also deduced in details. The removal of o-chlorophenol by sulfate radicals generated by heat activation of potassium persulfate was investigated. This research focused on the influence of temperature, pH, humic acid (HA), and inorganic ions to the removal efficiency. The results indicated that the increasing temperature and persulfate concerntration promoted the degradation of o-chlorophenol. Degradation of o-chlorophenol exhibited a second-order kinetics and the activated energy was 4.32 kJ·mol-1. Acidic condition is more beneficial for the o-chlorophenol degradation than alkaline condition. Both HA and CO32- inhibited the o-chlorophenol degradation. Cl- also inhibited the reaction at acidic and neutral conditions. However, at basic condition, such inhibition was not significant. It was presumed that o-chlorophenol was eventually mineralized. However, chlorophenol dimers as intermediates were detected during this process.The removal of o-chlorophenol by sulfate radicals generated by cobalt ion catalytic of potassium hydrogen sulfate was also investigated.It was found that o-chlorophenol could hardly be removed by the single reactant of PMS.The increasing concerntration of PMS and Co2+ promoted the degradation of o-chlorophenol. Both HA and CO32- inhibited the o-chlorophenol degradation. The existence of high Cl- concentration decreased o-chlorophenol degradation and on the contrary, low Cl- concentration promoted the o-chlorophenol degradation. In the end, o-chlorophenol was eventually mineralized to small molecule organic matters such as acetic acid.The removal of methyl orange by sulfate radicals generated by cobalt ion catalytic of potassium hydrogen sulfate was studied.It was found that methyl orange could be effectively degraded through the method of cobalt ion catalytic of potassium hydrogen sulfate. The increasing concerntration of Co2+ and Cl- promoted the degradation of o-chlorophenol but CO32- inhibited the o-chlorophenol degradation.The researches about using advanced oxidation process based on sulfate radicals to remove o-chlorophenol, methyl orange in water were helpful to explain the generation mechanism of sulfate radicals, and also helpful to provide technical support for actual applications in waste water treatment processes.