Environ Technol. 2014 Mar-Apr;35(5-8):917-24. doi: 10.1080/09593330.2013.856926.
Nitrate pollution in groundwater shows a great threat to the safety of drinking water. Chemical reduction by zero-valent iron is being considered as a promising technique for nitrate removal from contaminated groundwater. In this paper, Fe0/Pd/Cu nano-composites were prepared by the liquid-phase reduction method, and batch experiments of nitrate reduction by the prepared Fe0/Pd/Cu nano-composites under various operating conditions were carried out. It has been found that nano-Fe0/Pd/Cu composites processed dual functions: catalytic reduction and chemical reduction. The introduction of Pd and Cu not only improved nitrate removal rate, but also reduced the generation of ammonia. Nitrate removal rate was affected by the amount of Fe0/Pd/Cu, initial nitrate concentration, solution pH, dissolved oxygen (DO), reaction temperature, the presence of anions, and organic pollutant. Moreover, nitrate reduction by Fe0/Pd/Cu composites followed the pseudo-first-order reaction kinetics. The removal rate of nitrate and total nitrogen were about 85% and 40.8%, respectively, under the reaction condition of Fe-6.0%Pd-3.0%Cu amount of 0.25 g/L, pH value of 7.1, DO of 0.42 mg/L, and initial nitrate concentration of 100 mg/L. Compared with the previous studies with Fe0 alone or Fe-Cu, nano-Fe-6%Pd-3%Cu composites showed a better selectivity to N2.
地下水硝酸盐污染对饮用水安全构成了巨大威胁。采用零价铁的化学还原法被认为是一种从受污染地下水中去除硝酸盐的有前途的技术。本文采用液相还原法制备了 Fe0/Pd/Cu 纳米复合材料，并在不同操作条件下进行了用制备的 Fe0/Pd/Cu 纳米复合材料还原硝酸盐的批实验。结果表明，纳米 Fe0/Pd/Cu 复合材料具有催化还原和化学还原的双重功能。Pd 和 Cu 的引入不仅提高了硝酸盐的去除率，而且减少了氨氮的生成。硝酸盐去除率受 Fe0/Pd/Cu 的用量、初始硝酸盐浓度、溶液 pH 值、溶解氧（DO）、反应温度、阴离子和有机污染物的存在的影响。此外，Fe0/Pd/Cu 复合材料的硝酸盐还原符合准一级反应动力学。在反应条件为 Fe-6.0%Pd-3.0%Cu 用量为 0.25 g/L、pH 值为 7.1、DO 为 0.42 mg/L、初始硝酸盐浓度为 100 mg/L 时，硝酸盐和总氮的去除率分别约为 85%和 40.8%。与单独使用 Fe0 或 Fe-Cu 的先前研究相比，纳米 Fe-6%Pd-3%Cu 复合材料对 N2 具有更好的选择性。
