生物质炭负载纳米零价铁对水中硝态氮的还原去除机理研究

摘要

采用液相还原法成功制备纳米零价铁,并组装出生物质炭负载纳米零价铁复合材料(NZVI/BC).XRD图谱显示,NZVI/BC由生物质炭(BC)和纳米零价铁(NZVI)两种成分复合而成;SEM图像显示,加入生物质炭之后,NZVI颗粒在炭表面分散良好.研究考察溶液pH值、还原剂投加量、铁/炭比和NO3初始浓度等因素对NZVI/BC还原性能的影响.结果表明,NZVI/BC显示出优良的还原性能.在相同条件下,反应2h,NZVI对NO3-的去除率为75％,而NZVI/BC对NOr的去除率为96％.NZVI/BC是一种具有应用前景的硝态氮净化材料.%In this study,biochar supported nanosized zero valent iron composite (NZVI/BC) was assembled from biochar and nanoscale zerovalent iron (NZVI),while NZVI was prepared by liquid phase reduction method.The XRD patterns showed that NZVI/BC was composed of biochar and NZVI.SEM indicated that NZVI particles agglomerated greatly,and dispersed well after being distributed on biochar grains.The focus was placed on the effects of the solution pH,dosage and ratio of Fe/C for the composite as well as the initial concentration of NO3-on the reduction of nitrate by NZVI/BC.The research clearly demonstrates that NZVI/BC exhibits highly efficient reductive capability.The reductive removal rate of NO3-reached approximately 75 ％ within 2 h by using NZVI,and reached approximately 96 ％ by NZVI/BC under the same certain condition.Therefore,NZVI/BC is a promising scavenging material for nitrate.