Ferrous sulfate is usually light green crystal or light white powder, which is due to the different crystal water contained in ferrous sulfate. Strictly speaking, ferrous sulfate with different crystal water is not the same substance, but from the perspective of use, the difference in the use effect of ferrous sulfate with different crystal water is not too big.

At present, ferrous sulfate is widely used in the following aspects:

1. Ferrous sulfate can be used as flocculant for water treatment, which has good effect in the treatment of urban sewage and industrial wastewater, especially in the treatment of some sewage containing more phosphorus, and can effectively avoid eutrophication of water body.

2. Ferrous sulfate has strong reducibility and can reduce all kinds of metal compounds.

3. Ferrous ion in ferrous sulfate is an important part of hemoglobin in human and animal blood, so ferrous sulfate can be used for medical processing and as an iron supplement for human body.

4. Ferrous ion in ferrous sulfate is also a component of plant chlorophyll, so it is often used in agriculture and flower cultivation, which can achieve a good effect of plant iron supplement.

5. Ferrous sulfate is also one of the commonly used drugs in some laboratories. We can use ferrous sulfate for some experiments.

Ferrous sulfate has many uses, but reasonable use can achieve the desired effect, so we need to have a certain understanding of ferrous sulfate.