A system for making use of rainwater falling on houses and buildings, which comprises
a means for removing a predetermined quantity of initial precipitation from the
rainwater collected form the roof surface of the building; and a purifier receiving
the subsequent rainwater from which the initial precipitation has been removed.
The purifier includes a filtering tank, a sterilization tank, and a supply tank
connected to the sterilization tank. The filtering tank has a physical filter and
a pH adjusting agent, the sterilization tank contains a primary reactive catalyst
for producing active oxygen species, and the supply tank supplies aqueous hydrogen
peroxide to the primary reactive catalyst. The system also has a storage tank that
stores the purified rainwater supplied from the purifier. The storage tank contains
a secondary reactive catalyst for decomposing and eliminating residual active oxygen
species remaining in the purified rainwater supplied from the purifier.
