纳米铁炭微电解体系去除地下水中硝酸盐的机理及应用研究

Nitrate level in groundwater is increasing in China and conventional water treatment techniques are faced challenge. Nanocrystalline iron and carbon micro electrolysis process as a new technique, can remove nitrate in groundwater potentially. Study on this process may tackle the shortage of water resources and problem of groundwater contamination. Based on the previous achievements, good adsorption and desorption of activated carbon in this project is combined with strong reducing property of nano iron. The effect of iron carbon micro electrolysis system will be investigated on degradation of nitrate pollutants and some common characteristics will be explored. The objections of the study include developing nanometer iron-carbon particles and dispersed suspension, showing the relationship between features and geometry size of material, showing the relationship between effective loads of carbon particles and reducing property of nano iron, detecting the mechanism of removal improvement and the mechanism of nitrate degradation and reaction kinetic. Through the study, a theoretical and scientific supports can be provided with development and mechanism of iron carbon micro electrolysis materials. Additionally, the study can indicate a new technical process and method to improve nitrate removal in groundwater.

针对我国地下水硝酸盐氮污染日益严峻的形势和常规地下水处理技术存在的不足，研究纳米铁炭微电解技术去除地下水硝酸盐氮的关键科学问题，对于解决水资源匮乏和地下水污染问题有着十分重要的意义。本课题拟在已有工作的基础上，结合活性炭良好的吸附解吸性能和纳米铁的强还原性质，研究铁炭微电解体系降解硝酸盐氮污染物过程中的共性特征和基本规律，力争在纳米铁炭复合颗粒及分散悬浮液的宏量制备、材料基本性能与其微观几何尺寸之间的关系、炭颗粒有效负载和纳米铁还原性能的构效关系、去除过程的优化控制和去除效率提高的基本规律、硝酸盐的降解机理及反应动力学等方面做出有益的探索。为新型铁炭微电解复合材料研制及其机理研究提供较系统的理论基础和科学依据，为地下水硝酸盐污染物的有效去除提供新的技术路线和方法。

我国地下水硝酸盐氮污染日益严峻并且常规地下水处理技术不足，而研究纳米铁炭微电解技术去除地下水硝酸盐氮存在一系列问题，我们针对这些关键科学问题进行了深入研究。采用液相还原法制备纳米铁炭复合材料，讨论了制备材料过程相关工艺参数如硼氢化钠加料速率、炭铁比例、加炭时间以及制备反应体系机械搅拌强度等对材料去除硝酸盐性能的影响，获得了最佳的制备条件参数；对纳米铁炭微电解体系进行探讨，研究电解作用影响因素；对反应过程进行系统分析，包括材料的前后变化，N的转化，溶液中pH变化等，从而找出主要的反应途径；通过对不同动力学模型的拟合，包括一级反应、二级反应、一级吸附、二级吸附、非均相催化模型等，建立适合的动力学模型以及适用条件，为纳米铁炭微电解体系的实际应用提供一定的理论支撑；采用鼠李糖脂对纳米铁进行改性后负载在活性炭上制备出改性纳米铁/炭,将其作为PRB填充材料,并采用有机玻璃柱模拟连续墙式PRB来进行水中硝态氮地去除研究。