Copper sulphate is a moderate to low toxicity, and it does not matter if a small amount of solution contacts the skin. Discarded copper sulphate can be disposed of after disposal, or it can be recycled after treatment. It can not be directly poured into the sewer to avoid polluting the environment.
Treatment method after copper sulfate is treated and then discarded:
A small amount of calcium hydroxide can be added to the discarded copper sulfate to precipitate copper ions, and some biochemicals can also be added, which can also achieve good results. It is also possible to directly add an appropriate amount of the NA2S solution to precipitate a CuS which is difficult to dissolve, and then pour off the precipitate and the suspension of the solution (CuS, Na2SO4), thereby preventing the free heavy metal ion Cu2+ from contaminating the water.
Industrially, waste copper sulphate can be treated and recycled, as follows:
Adding NAOH to copper sulfate produces copper hydroxide precipitate, then filtering leaves a precipitate, and the filtrate (Na2SO4) is poured off. The precipitate is washed and dried to prepare Cu(OH)2 precipitate, then Cu(OH)2 The precipitate is mixed with a certain proportion of 98% concentrated sulfuric acid to regain the CuSO4•5H2O crystal.