WASTEWATER TREATMENT FOR PIG FARMS
Date public: 31-05-2024||View: 2080
Pig farming is a significant business activity that impacts the economy. However, the treatment of pig farming wastewater poses a serious environmental threat that must be strictly regulated by the government to protect the living environment. So, what is the correct and most effective treatment method? Let's explore this with Đại Nam Environmental.
1. Overview of Livestock Wastewater
Livestock wastewater is defined as wastewater generated from livestock activities such as cattle, poultry, and animal farming, typically from pig and cattle farms.
Usually, when domestic wastewater is combined with livestock wastewater, it is considered livestock wastewater.
According to the latest national technical standards for livestock wastewater, before being discharged into the environment, the parameters within the wastewater must not exceed the allowable limits.
The parameters within the livestock wastewater must not exceed the allowable limits
2. Components of Pig Farming Wastewater (Pig Farming Wastewater Treatment Technology)
Compared to other types of wastewater, pig farming wastewater does not contain many harmful chemical components such as acids, alkalis, heavy metals, etc., but it does contain many types of bacteria, larvae, and parasites.
Current components of livestock wastewater
The components in pig farming wastewater pose a high risk of directly affecting human health, especially when living in a polluted environment for an extended period.
Some diseases easily recognized due to the impact of pig farming wastewater include respiratory diseases such as lung cancer, skin diseases such as skin cancer, caused by pollutants present in the water.
Organic matter: Organic compounds make up 70–80% of the wastewater, including cellulose, protein, amino acids, fats, carbohydrates, and their derivatives, as well as leftover food. Inorganic compounds make up 20–30%, including sand, soil, salts, urea, ammonium, chloride salts, and SO4.
N and P: The absorption of N and P by livestock is very poor, so when they consume feed containing N and P, these elements are excreted through feces and urine. Pig farming wastewater often contains high levels of N and P. Total N = 200–850 mg/l, with N-NH4 accounting for about 80–90%; total P = 60–100 mg/l.
Pathogens: Livestock wastewater contains many types of bacteria, viruses, and parasite larvae that can cause disease.
3. Pig Farming Wastewater Treatment Process Using Biogas Technology
There are many solutions for treating pig farming wastewater depending on the scale of the farm and economic conditions, such as composting, biogas technology, and biological ponds. Among these, biogas technology is highly regarded for several advantages:
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Maximally eliminates odors from the wastewater
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Utilizes biogas as fuel, helping to save significant costs
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Reduces the pollution level of the wastewater
So, how is the pig farming wastewater treatment process using biogas technology carried out?
Pig farming wastewater is channeled into a biogas digester to process organic matter, significantly reduce the emission of harmful gases, kill pathogens in the wastewater, and simultaneously provide a low-cost fuel source.
Pig farming wastewater treatment process
After the wastewater fills the biogas digester, it flows through pipes into an equalization tank, where it is mixed to balance the concentration and flow of the wastewater.
Then, the wastewater is directly transferred to the bottom of the UASB tank, where it is evenly distributed. It then flows upward through a layer of small granular biological sludge (sludge flocs), where organic contaminants are consumed. Methane and carbon dioxide bubbles rise to the surface, where they are collected by a gas cap and channeled out of the tank.
The wastewater continues to flow into the anoxic tank. Under the influence of obligate and facultative anaerobic bacteria, complex compounds are broken down and converted into simpler substances that are easier to treat through various biological reactions.
The wastewater then flows into the aerotank, an aerobic tank containing a mixture of wastewater and activated sludge. Air is continuously supplied to the tank to mix and suspend the sludge in the wastewater, providing sufficient oxygen for microorganisms to oxidize the organic matter in the wastewater.
Suspended particles act as nuclei for bacteria to reside, reproduce, and grow into sludge flocs, known as activated sludge. Substrates (BOD) and nutrients (N, P) serve as the main food source, converting them into insoluble inert substances and new cells of bacteria and living microorganisms.
The amount of activated sludge produced during the retention time in the aerotank for the initial wastewater is not sufficient to rapidly reduce organic matter, so a portion of the activated sludge that has settled at the bottom of the biological settling tank is recirculated back to the aerotank to maintain the concentration of microorganisms in the tank.
Excess activated sludge is sent to a sludge tank, then to a sludge drying bed. The sludge is collected for fertilizer production.
For the aerotank to operate effectively, it must be continuously supplied with sufficient air. The treated wastewater from the aerotank continues to flow into the settling tank, where the clean water is transferred to the disinfection tank.
In the disinfection tank, NaOCl is added to kill any remaining bacteria. The water then flows into a biological pond, helping to stabilize the water and reduce pathogenic microorganisms.
To effectively understand and apply the pig farming wastewater treatment process in your farm, you can contact Đại Nam Environmental Solutions via hotline 0909 378 796 or email info@dainam-enviro.com for consultation and the most effective livestock wastewater treatment solutions.
