电化学/催化加氢工艺去除硝酸盐的动力学及机理

摘要

为解决地下水硝酸盐(NO3--N)污染问题,采用电化学/催化加氢耦合工艺对其进行去除,重点考察该工艺对NO3--N的降解动力学及反应机理.结果表明,电化学/催化加氢耦合工艺在厌氧条件下能够在短时间内将NO3--N完全去除,去除速率(以N计)可达72.6 mg.L-1.h-1 ,反应符合二级反应动力学规律,常数k=0.005 5 cm2.mA-1.min-1 . 水中NO3--N一部分由电化学反硝化降解去除,另一部分由催化加氢还原去除,两种反应通过电解水产H2反应耦联成为一个整体,宏观上符合电化学反硝化机理.%The kinetics and mechanism in the electrochemistry/catalytic hydrogenation ( E/C ) coupling process, which was employed to remove nitrate ( NO3--N ) from groundwater, was investigated in this paper. The results demonstrated that the NO3--N could be rapidly removed by E/C under anoxic conditions, and the degradation efficiency of NO3--N followed the increasing current density(ID) with observed second order reaction rate and the constant( k ) value of 0. 005 5 cm2·mA-1·min-1 . The NO3--N reductive by E/C with two kinds of reactions, electrochemistry denitrification and catalytic reduction, both of which aggregated by the reaction of brine electrolysis.