Application of Polyaluminum Chloride in Aquaculture

    Polyaluminum chloride, also known as polyaluminum, polymeric aluminum, abbreviated as PAC, is an organic polymer water purifier with excellent performance, has good water purification and decolorization performance, and has a wide range of uses, including purification of potable water, sewage; purification of industrial water, industrial wastewater, mines, oilfield refill water, purification of water, gold, coal washing, leather and various chemical sewage treatment, etc. and industrial production applications.

    Working principle

The hydrolysis-polymerization product generated by adding trivalent aluminum salt of polyaluminum chloride into water carries out the physicochemical effects of electrical neutralization, destabilization and adsorption bridging on organic matter in water, generating coarse particles of flocs to purify water quality.

Performance characteristics

    Flocculants are divided into inorganic flocculants and organic flocculants, traditional inorganic flocculants include aluminum sulfate, aluminum chloride, ferric sulfate, ferric chloride, etc. Compared with these inorganic flocculants, the advantages of polyaluminum chloride are very prominent.

1. pH stability. polyaluminum chloride after a large number of inputs can still maintain pH stability, unlike aluminum sulfate that is easy to make the water acidic.

2. Small dosage and low cost. As a high-efficient water purification agent, polyaluminum chloride is used in small dosage, the purified water quality is better than aluminum sulfate flocculant, and the cost of water purification is 15-30% lower than that of aluminum sulfate flocculant.

3. Fast purification speed and high efficiency. polyaluminum chloride flocs form fast, fast settling speed, than aluminum sulfate, sodium thiosulfate and other traditional products with strong processing capacity; microorganisms in the water and other organic matter removal rate is high, good adsorption effect of heavy metal ions, can effectively reduce the COD in the water, BOD, the experimental data show that the use of the effect of aluminum sulfate than the traditional 2-4 times higher.

4. High decolorization efficiency. High turbidity, high chromaticity of the water body has a high purification effect.

    In recent years, with the aquaculture water quality eutrophication, tail water discharge pollution and other issues are becoming increasingly prominent, in order to ensure the green and healthy development of the fisheries industry, China vigorously carry out aquaculture water quality pollution control work, and to manage water quality problems, the use of polyaluminum chloride, then polyaluminum chloride in the aquaculture water is how to apply it, specifically the following aspects.

1. Breeding tail water treatment.

Pond aquaculture water quality contains a large number of breeding residual bait and fish feces and other organic matter, resulting in a decline in the transparency of the water body, water quality eutrophication, direct discharge will cause environmental pollution. It is necessary to filter and purify the pond breeding water to meet the emission standards before discharge or recycling. The use of polyaluminum chloride can make the colloidal particles in the water difficult to precipitate rapid and efficient coagulation, agglomeration, flocculation into larger particles and precipitation, significantly reducing the COD, BOD, greatly improving the efficiency of tail water treatment.

2. Special extreme weather water quality treatment.

High temperature and rain in summer, easy to cause flooding, a large number of mud, all kinds of surface debris easily into the breeding pond, resulting in water turbidity, and then stimulate the breeding of fish, resulting in stress death. At this time you can add polyaluminum chloride, can be quickly settled in the water body of sediment and organic matter, to avoid turbidity of the pond water, so that the pond quickly restore the transparency, and improve the phytoplankton oxygen generation capacity. At the same time, after the flood, the water body pH is easy to over-acid, polyaluminum chloride pH alkaline, can also play a role in stabilizing the water body pH.

3. Pond "water" treatment

Due to hot weather, improper use and other factors, easy to cause the death of algae in the pond, thus affecting the survival of fish, may start the effect of the oxygenator is not obvious, resulting in the so-called "inverted algae" or "turn the water". The algae that died after the "water transfer" are decomposed into various kinds of large molecules and small molecules of organic matter, which makes the water quality look black or red. polyaluminum chloride has good complexation, adsorption, through the use of polyaluminum chloride, rapid adsorption, complexation of dead algae, and then refill the new water, water quality adjustment, so as to achieve the management of the "turn of the water effect.

4.Deodorization and sterilization

    Polyaluminum chloride in aquaculture with deodorization, antibacterial, disinfection, can decompose oxides to generate organic matter, organic sulfides, organic nitrogen, absorption and decomposition of ammonia, nitrite and other toxic substances, and can quickly kill harmful organisms, prevent the growth of decay microorganisms.

Precautions

1. polyaluminum chloride has water absorption. It should be kept dry and away from heat, and the preservation environment is strict.

2. polyaluminum chloride is corrosive. When using it, wear mask, gloves and working clothes to avoid splashing on the skin and damaging the staff's health.

3. Pay attention to environmental factors. In the higher temperature, breeding density of ponds using polyaluminum chloride water purification effect is obvious, in the use of bactericidal, insecticidal disinfectant before splashing polyaluminum chloride can better ensure the effect of disinfection, insecticidal. However, this effect is only temporary, only the toxic and harmful substances in the breeding water body are temporarily stored in the bottom of the pond. Avoid using it in bad weather such as cloudy and rainy days, so as not to cause the lack of oxygen in the pond; use it when the temperature is low.