Characteristic of KMnO 4 -modified corn straw biochar and its application in constructed wetland to treat city tail water

Biochar prepared from straw as constructed wetland (CW) substrate reduces straw pollution and simultaneously promotes the wastewater treatment efficiency of CW. In order to further analyze the pollutant removal mechanism of KMnO 4 -modified biochar substrate, the KMnO 4 -modified biochar was characterized. The experiment on city tail water treatment by CW with biochar was analyzed. The research showed that the surface property improvement on KMnO 4 (0.1 mol/L)-modified biochar was the most obvious. The biochar modified by 0.1 mol/L KMnO 4 increased the SSA and the number of oxygen functional groups and alcohol hydroxyl. KMnO 4 -modified biochar improved the removal efficiency of NO 3 − -N in CW. KMnO 4 -modified biochar substrate with plants improved the TP removal efficiency (about 45%). KMnO 4 as modifier reduced the influence of biochar on electrical conductivity tracing experiment. This study will improve the utilization value of straw and the removal efficiency of CW.