Pig farming wastewater: How to calculate volume & treat effectively

Water supply for pig farming(Pig)

Water supply for daily drinking needs

• The daily drinking water needs of pigs depend on many factors such as breed, age, diet, food quality, environmental temperature, health status… each age group has different water needs.

• According to TCVN 3772:1983 on pig farms – design requirements, the maximum water supply for adult pigs is about 10 liters/head/day.

Water supply for activities, bathing pigs, washing pens and equipment

• According to TCVN 3772:1983 on pig farms – design requirements, water supply standards for pig bathing and barn washing with pigs is 5 liters/m2.

Wastewater from pig farming

Among the types of livestock waste, liquid waste is the type of waste with the largest volume. Especially when the wastewater from bathing and cleaning the barn is mixed with the urine excreted by pigs. This is also a type of waste that is difficult to manage and treat as well as greatly affects the environment. Livestock wastewater includes:

The amount of urine excreted is estimated according to the following standards:

• Wastewater generated is calculated at 80% of the amount of water for pigs to drink

• Chemical composition in urine excreted by pigs

[Source: Truong Thanh Canh and collaborators (1997-1998). Excerpt from Nguyen Ha My (2002)]

Amount of wastewater from cleaning barns and bathing pigs:

• Because water from cleaning barns and bathing pigs will be lost into barns and pigs, wastewater accounts for about 80% of the water supply.

• The most important characteristic of wastewater generated from livestock farms, especially pig farms, is the content of organic substances and nutrients expressed through parameters such as: COD, BOD5, TN, TP, SS…These parameters are the main causes of environmental pollution. These are easily decomposable components, causing foul odors, generating toxic gases, reducing the amount of dissolved oxygen in water and especially if not treated when discharged into receiving sources, it will pollute the environment, cause eutrophication of the ecosystem, affect crops and be an important source of nutrients for harmful bacteria to grow. In addition, wastewater from livestock farms contains a large amount of disease-causing bacteria, which is a factor that directly affects the health of humans and animals in the area.

• In pig farms, cleaning manure with water is widely used, creating a large amount of wastewater. In wastewater, organic compounds account for 70-80%, including cellulose, protein, amino acids, fats, carbohydrates and their derivatives in manure and leftovers. Most organic substances are easily decomposable, inorganic substances account for 20-30% including sand, soil, salt, urea, ammonium, salt, chloride, SO42-… Chemical compounds in manure and wastewater are easily decomposed, pollution characteristics are shown specifically in the following table:

• Characteristics and composition of livestock wastewater of the project contain many easily decomposable organic impurities shown through the parameters of BOD, total N, total P and pathogenic microorganisms.

Table: Quality of untreated wastewater

Source of article : Institute of Strategy and Policy on Natural Resources and Environment

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