Study on Nitrate Removal with Nanoscale Zero-valent Iron Prepared by Hydrogen Reducing Goethite

Nanoscale zero-valent iron(NZVI) with particle size of 14 nm was prepared by hydrogen reducing natural goethite.The nitrate removal by NZVI and the effect factors were investigated,and the comparison between NZVI and ordinary zero-valent iron(OZVI) was made.The results show that the removal efficiency of nitrate by NZVI is less influenced by pH value when compared with OZVI.The removal rate of nitrate can reach more than 90% when the iron-to-nitrate ratio is 40 ∶1,the reaction time is 5 h and the nitrate concentration is 60 mg/L.NZVI has high reduction activity for nitrate,and the end products have no nitrite.The dissolved oxygen and natural goethite particle size have less effect on nitrate removal.This method is relatively simple and low in cost,so NZVI has potential application in nitrate removal from groundwater.