Copper sulfate to hydrogen peroxide

Copper sulfate and hydrogen peroxide can react chemically to produce copper peroxide and oxygen copper sulfate. It is a blue transparent crystal that can weather in dry air and becomes weakly acidic when dissolved in water. It is a relatively important metal salt. Copper sulfate is often used for disinfection in the aquaculture industry. Next, let’s take a look at some of the effects of copper sulfate.

The reaction of copper sulfate with hydrogen peroxide

The precipitate should be brown copper peroxide, producing oxygen. The process is as follows: (→← indicates reversible)

CuSO4+H2O2→←CuO2+H2SO4

CuO2+H2O→←CuO2·H2O

2CuO2·H2O→←2Cu(OH)2+O2

Cu(OH)2+H2SO4→←CuSO4+H2O

All the above processes are reversible, so the actual overall reaction can be considered as the decomposition of hydrogen peroxide.

Characteristics of copper sulfate and factors affecting its effects

Copper sulfate is a blue transparent crystal block or crystalline granule or powder with a metallic taste. It will slowly weather when exposed to dry air. This product is easily soluble in water and its aqueous solution is weakly acidic. Copper sulfate belongs to the class of heavy metal salts. Its hydrolyzed copper ions (Cu2+) can combine with proteins to form protein salts, which have a strong toxic effect on protozoa and lower algae with colloid.

The main factors affecting the toxicity and safe concentration of copper sulfate include pool water temperature, hardness, pH value, organic matter content, etc. Generally speaking, the higher the water temperature, the more toxic the copper sulfate is, and the lower the safe concentration. In summer, 0.5 ppm is enough to kill filariasis, while 1.4 ppm is needed in winter to be effective. The greater the hardness of the water, the lower the toxicity of copper sulfate, because carbonates can react with copper sulfate to form a blue-green alkaline carbonate precipitate. Thereby reducing the efficacy of the drug; the pH value is related to the carbonate content. The more carbonate, the higher the pH value and the lower the toxicity. The dissolved organic matter in the water, especially proteins and polyhydroxy compounds, can form organic complexes with copper sulfate, thereby reducing its toxicity; secondly, the metal compounds in the water can react chemically with copper sulfate to reduce its toxicity. For example, the toxicity of copper sulfate decreases when the water contains salt or calcium chloride.

In addition, different fish species have different tolerance to copper sulfate. It is reported that the sensitivity of fish to copper sulfate is as follows: salmon, followed by grass carp, silver carp, and then carp, crucian carp and tilapia. It has been determined that when the copper ion (Cu2+) content in water is 0.012 mg/L, the food intake of salmon fry is significantly reduced, and when it exceeds 0.017 mg/L, they stop eating. When the copper ion content in water reaches 5-10 micrograms per liter, the nitrogen fixation and photosynthesis of blue algae are inhibited. Silver carp's 50% avoidance concentration of copper sulfate is 0.3ppm. When the copper sulfate concentration is lower than 0.5ppm, it has no killing effect on fish parasites. When it exceeds 0.8ppm, it can easily cause fish poisoning and death, thus reducing the safe concentration. The risk increases.

Another problem in the use of copper sulfate is that copper ions easily accumulate in the body, causing kidney necrosis in fish, decreased hematopoietic function, reduced activity of intestinal digestive enzymes, and causing digestive system disorders.