【摘要】 利用液相还原法制备壳聚糖稳定纳米铁、油酸钠稳定纳米铁和普通纳米铁,在无氧条件下将其分别与反硝化细菌耦合用于地下水中硝酸盐污染物的去除研究,探讨不同纳米材料与反硝化菌的耦合体系去除硝酸盐的速率和产物,并通过测定体系中反硝化细菌总RNA浓度的变化来研究纳米材料对反硝化菌的毒害作用。结果表明,耦合体系均在9d内将硝酸盐完全去除,反应过程中有大量亚硝酸盐产生,但随着反应的进行又逐渐消失,3种耦合体系的脱氮产物中均有氨氮产生,油酸钠稳定纳米铁体系、普通纳米铁体系、壳聚糖稳定纳米铁体系产生的氨氮比例分别为15、37和58。反应后3种耦合体系中反硝化菌总RNA浓度的降低率分别为壳聚糖稳定纳米铁体系37、纳米铁体系30、油酸钠稳定纳米铁体系21,可见不同纳米材料对细菌毒性大小顺序为壳聚糖稳定纳米铁>普通纳米铁>油酸钠稳定纳米铁。综合反应速率、产物和对细菌的毒性各个方面因素,油酸钠稳定纳米铁与反硝化细菌的耦合效果最好。更多还原

【Abstract】 An integrated nitrate treatment using nanoscale zero-valent iron(NZVI) and Alcaligenes eutrophus,which is a sort of hydrogenotrophic denitrifying bacteria,was conducted to remove nitrate and decrease ammonium generation.In this paper,nano-scale chitosan-Fe0,sodium oleate-Fe0 and nano-Fe0 were synthesized respectively using liquid-phase reduction method and then integrated with denitrifying bacteria to remove nitrate from groundwater under anaerobic condition.Experiments were carried out to examine the removal rate of nitrate,the reaction products and the RNA concentrations in these particle-bacteria systems.The results showed that nanoparticles-bacteria systems removed all nitrate within 9 days.During the reaction,the nitrite increases firstly,achieving the maximum value and then decreased.The ammonium increased monotonously,the ratio of ammonium was as follows:58% in chitosan-Fe0 system,37% in nano-Fe0 system,and 15% in sodium oleate-Fe0 system.The total RNA concentrations of the bacteria decreased in content by 37%,30%,and 21% in the chitosan-Fe0,nano-Fe0 and oleate-Fe0 nanoparticles-bacteria systems respectively,which suggested the toxicities of these nanoparticles to denitrifying bacteria should be in the following sequence:chitosan-Fe0>nano-Fe0>sodium oleate-Fe0.In summary,considering the various factors synthetically(removal rate of nitrate,reaction products,and toxicities to bacteria),sodium oleate-Fe0 could be applied as a promising reactive material for the reduction of nitrate in groundwater under anaerobic condition together with denitrifying bacteria.更多还原