这个是净水系统加进去的，目的是防止管道氧化生锈：Hydrazine hydrate is mainly used as a raw material for plastic foaming agents, with 28% of hydrazine used in water treatment and pH control. Oxygen dissolved in water causes corrosion. Because hydrazine removes this oxygen via the reaction N2H4 + O2 → N2 + 2H2O, it is useful in preventing corrosion.