海绵铁作为渗透反应墙介质去除地下水中NO_3^--N的初步研究  

Preliminary study on nitrate removal from groundwater by permeable reactive barrier with sponge iron as the media

作　　者：顾莹莹[1] 雷亚妮 高孟春[3] 贾永刚[3] 李鸿江[4] 

机构地区：[1]中国石油大学(华东)环境与安全工程系,山东青岛266580 [2]青岛骄鹏工程技术研究所,山东青岛266023 [3]中国海洋大学环境科学与工程学院,山东青岛266100 [4]清华大学环境学院,北京100084

出　　处：《环境污染与防治》2013年第4期33-37,42,共6页Environmental Pollution & Control

摘　　要：采用孔隙率高、比表面积大的海绵铁作为渗透反应墙(PRB)介质,通过3批动态实验讨论了海绵铁+锰砂单层介质、海绵铁+锰砂+活性炭单层介质,以及海绵铁+锰砂和活性炭的双层介质对地下水中NO3--N的去除效果。结果表明,经过292h的PRB动态实验,填充海绵铁+锰砂单层介质、海绵铁+锰砂+活性炭单层介质、海绵铁+锰砂与活性炭双层介质的反应器的NO3--N去除率分别达到了70.65%、84.22%、88.09%,采用海绵铁与活性炭的单层介质或双层介质的反应器对地下水中NO3--N和TN的去除效果显著增强,出水中NH4+-N浓度相对也有所降低;扫描电镜和X射线衍射分析结果表明,经过PRB动态实验后,海绵铁表面覆盖了厚厚的膜,微孔隙被许多新的物质堵塞,这会导致海绵铁的氧化还原反应能力减弱,阻碍地下水中NO3--N的进一步还原去除,这也是以后实际应用中需要解决的问题。Sponge iron with high porocity and large specific area was used as the reactive media of permeable reactive barrier to removal nitrate from groundwater. Three batches of dynamic experiments were carried out to investi~ gate the effects of different reductive media （sponge iron 4- manganese sand mixed media, sponge iron 4- manganese sand 4- granular activated carbon mixed media, and sponge iron 4- manganese sand and granular activated carbon double layer media） on nitrate removal efficiency. Results showed that the removal effeciencies of nitrate from groundwater by the three permeable reactive barriers were 70.65%, 84.22 % and 88.09 %, respectively after 292 h of reaction. It indicated that the addition of granular activated carbon could enhance the removal of the nitrate and total nitrogen from groundwater, the effluent NH4＋-N of permeable reactive barrier was also decreased in a certain degree. The surface image and mineral composition of sponge iron before and after reaction were also observed and analyzed by scanning electron microscopy and X-ray diffractometer, it was found that a thick film was covered on the surface of sponge iron, and lots of micro pore were choked up with new substances, this would decrease the redox ability of sponge iron and further hindered the removal of NO3-N from groumdwater. This problem should be solved in the futhre prictical application.

关 键 词：海绵铁 硝酸盐 地下水 渗透反应墙 

分 类 号：X523[环境科学与工程—环境工程]