中文摘要：

采用不同液相还原法制备纳米Fe0、Fe/Ni和Fe/Cu粒子,将其与反硝化细菌混合应用于地下水NO3--N去除研究。考察3种体系对NO3--N去除速率的影响,并对其脱氮产物及RNA水平上纳米铁系双金属对反硝化细菌的毒性效应进行了分析和讨论。结果表明,9 d内纳米Fe0体系可完全将NO3--N去除,过程中伴随NO2--N先升高后降低的生成趋势,NH 4＋-N生成52%;纳米Fe/Ni体系脱氮速率最快,6 d内可将NO 3--N完全去除,几乎未检测到NO 2--N的生成,而NH 4＋-N的转化率高达69%;纳米Fe/Cu体系7 d内可将NO3--N去除完全,NH4＋-N的生成率降低,仅39%,但是出现33%NO2--N积累。从反应前后反硝化细菌总RNA浓度变化看,3种纳米粒子对反硝化细菌的毒性大小为纳米Fe/Ni﹥纳米Fe/Cu﹥纳米Fe0。

英文摘要：

In this study,nano-scale Fe0,Fe/Ni and Fe/Cu synthesized with different liquid-phase reduction methods,were studied integrated with denitrifying bacteria to remove nitrate from groundwater.Batch experiments were carried out to examine the removal rate of nitrate and the products of the denitrification in these three systems.Also,the total RNA content of bacteria were studied to evaluate the toxicity of bimetallic nanopaticles to the integrated bacteria.The results showed that almost 100% removal of nitrate was reached within 9 days in the Fe0 nanoparticles system with nitrite transitory accumulation,and the ratio of ammonium to TN was 52%.The Fe/Ni nanoparticles system significantly enhanced the rate of nitrate reduction,removing almostly nitrate within a period of 6 days,hardly detecting the product of nitrite,while the ammonium of the final products was high to 69%.Nano-scale Fe/Cu system took 7 days to complete 100% removal of nitrate,producing less ammonium,only 39%,but there was 33% nitrite remained in the system.Experimental results also showed that the toxicity of these three types of nanoparticles to denitrifying bacteria should be in the sequence： nano-scale Fe/Ninano-scale Fe/Cu nano-scale Fe0.