Shrimp farming wastewater treatment

The shrimp farming industry tends to grow rapidly, with shrimp farms springing up in large numbers across the country. However, the shrimp farming process also generates many environmental consequences that need attention. In today’s article, we would like to send readers information about shrimp farming wastewater andtreatment methods for this type of wastewater.

Process of shrimp farming in the lagoon

            The shrimp farming process goes through the following three stages:

• Phase 1: Preparation
  • Water collection and water treatment
  • Choose breeds, care for and manage nursery ponds
• Phase 2: Shrimp farming
  • Shrimp transfer, care and management of nursery ponds
• Phase 3: Harvest
  • Harvesting and preservation

Basic shrimp farming process

Characteristics and pollution components of shrimp farming wastewater

Shrimp farming wastewater contains large amounts of organic matter and nutrients derived from leftover food and shrimp feces. Wastewater also contains many antibiotics and medicines to treat diseases for shrimp. Wastewater has high levels of nitrogen and phosphorus nutrients when discharged, causing eutrophication of water sources. In addition, the presence of organic substances and nutrients causes the content of BOD, COD, H2S,… to increase rapidly while the amount of oxygen in the water decreases, affecting the growth and development of farmed shrimp. as well as other organisms if shrimp farming wastewater is discharged without treatment.

Parameter table of shrimp farming wastewater pollution parameters

Choose treatment technology

Shrimp farming wastewater has extremely high levels of suspended solids, organic matter, and even nitrogen and phosphorus. Therefore, an anoxic process is needed to process nitrogen and phosphorus; flocculation – flocculation process to remove suspended solids and combine anaerobic and anoxic treatment of organic matter. The appropriate technology is to use AAO (Anaerobic –  Anoxic – Oxic) technology for treatment. The technological line is as follows:

Shrimp farming wastewater treatment technology line diagram

Explanation of shrimp farming wastewater treatment technology

Air conditioning tank

Wastewater is put into the regulation tank to help stabilize the concentration and flow before treatment.

Aerobic tank

Wastewater from the equalization tank is transferred to the anaerobic tank for anaerobic treatment. Here the anaerobic decomposition process takes place, anaerobic microorganisms work to help treat long-chain organic substances that are difficult to decompose, chlorine compounds and some heavy metals in wastewater. Part of the phosphorus in wastewater will be processed through the nutrient absorption mechanism of microorganisms.

Anoxic tank

Wastewater after treatment in the anaerobic tank is combined with the waste stream containing NO2-, NO3- circulating from the aerotank and transferred to the anoxic tank. Here the process of nitrite reduction and denitrification occurs, converting NO2-, NO3- into N2. After the treatment process, wastewater is transferred to the aerotank

Aerotank

Organic substances will be decomposed by aerobic microorganisms in an environment continuously supplied with oxygen. After aerobic treatment, wastewater is transferred to the coagulation – flocculation tank.

Flocculation tank

Here, use coagulants to help the flocculation – flocculation process take place better. The process of flocculation – flocculation increases the size and volume of flocs in water.

Settlement tank

The sludge will settle to the bottom of the tank while the clear water flows through the disinfection tank. The mud at the bottom of the tank is partly circulated to the aerotank, and partly transferred to the sludge tank for treatment.

Disinfection tank

The settled wastewater is transferred to the disinfection tank, where chlorine chemicals are added to eliminate disease-causing bacteria and viruses. The treated water is discharged to the receiving source.

Advantages and disadvantages of shrimp farming wastewater treatment system using AAO technology

Advantages

• Thoroughly treat the content of organic matter, nitrogen, phosphorus
• Low construction and operating costs
• Can easily increase capacity or relocate

Disadvantages

• Need large construction area
• Using many types of microorganisms requires specialized operators

The above is information and knowledge about shrimp farming wastewater as well as treatment methods. Hopefully this article will help readers gain more knowledge and aquaculture investors have an additional technology to treat shrimp farming wastewater.

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