RESUMO
A Pt/biochar electrode reactor was developed to remove humic acid in water. The removal efficiency and characteristics of the reactor were investigated. Experimental results showed that Pt/biochar electrode reactor obtained 74.58% removal rate after 300 min reaction under current density of 20 mA·cm-2. The removal rate was increased by 58.3% comparing with 47.10% removal rate achieved by Pt/graphite electrode reactor. Electrochemical oxidation and air floating played the main roles in removal of humic acid from water. The improved removal efficiency of humic acid in Pt/biochar electrode reactor was attributed to the fact that the biochar cathode could produce more H2O2 than graphite cathode. Three-dimensional excitation emission matrix fluorescence spectroscopy and Gel permeation chromatography measurement revealed that Pt/biochar electrode reactor had strong oxidation capability to mineralize the low molecular weight humic acid directly. It suggests that biochar could be use as an innovative cathode material of electrode reactor for organic pollutants treatment in water.