溶液中Fe2+强化Fe0还原NO3-的机制

通过不同条件下Fe0还原NO3-的研究发现，在中性条件下溶液中Fe2+明显强化了Fe0对NO3-的还原，最终还原产物以NH4+-N为主，而反应过程中Fe2+消耗与NO3-还原量存在明显的正相关性。在Fe2+初始浓度为1~8 mmol·L-1条件下，6 g·L-1的Fe0对初始浓度为100 mg·L-1 NO3-的还原符合零级反应动力学过程，结合电化学和X射线衍射分析，证明Fe2+通过沉积到Fe0表面，加速了电子传递过程，促进Fe0表面活性，从而强化了Fe0对NO3-的还原。

Mechanism of promotion effect of Fe2+ on nitrate reduction by Fe0

In this work, nitrate reduction by Fe0 under different conditions was studied. The results indicated that dissolved Fe2+ promoted the reduction of NO3- at a neutral pH. NH4+-N was the main reduction product, and the amount of consumed Fe2+ correlated positively with the amount of nitrate reduction. Moreover, with an initial concentration of 1 to 8 mmol·L-1 Fe2+, 100 mg·L-1 of nitrate (initial concentration) was reduced by 6 g·L-1 Fe0; this process conformed to zero-order reaction kinetics. Electrochemical measurements and X-ray powder diffraction (XRD) results indicated that Fe2+ accelerated the electron transfer process by precipitating on the surface of iron, which in turn promoted the surface activity of Fe0, and accelerated nitrate reduction.