Vietnam’s pig farming industry, from household scale to large-scale industrial farms, plays a crucial role in the country’s food security and economy. However, this rapid development brings with it a “serious problem”: environmental pollution from wastewater and solid waste.

Characterized by extremely high organic pollution, concentrations of Ammonia, Nitrogen, and Phosphorus exceeding thresholds, a large volume of solid waste from manure, along with unpleasant odors and the risk of disease outbreaks, pig farm wastewater, if not treated thoroughly, will cause severe pollution of water, land, and air, and directly affect public health. Is your farm facing pressure to comply with QCVN 62-MT:2025/BTNMT, are the operating costs of your existing treatment system too high, or are you simply looking for a “greener,” more efficient solution?

I. Characteristics of pig farming in Vietnam.

Household scale (or traditional farming):

• About 4 million households with a scale of 10-100 pigs in a small area, often combined with fish farming or cultivation
• Pig farming waste is used for fish feed or as manure for crops

Farm scale (industrial farming):

• About 5,000 farms with a scale of over 100 pigs in a large area
• Farms are divided into sow farms (with piglets) and market hog farms. Some farms mix sows and market hogs.

1.2. Distribution of pig farms in Vietnam

Pig farms are mainly distributed in the Red River Delta, Central Highlands, Northern mountainous region (25%); North Central Coast and South Central Coast (19%); Mekong River Delta (13%); Southeast and Central Highlands (11% and 7%)

II. Composition of pig farm wastewater.

Livestock wastewater in general and pig farm wastewater in particular is a mixture of animal excretions and water used for cleaning pens. Although it does not contain toxic substances like wastewater from other industries (acids, alkalis, heavy metals…), it contains many bacteria, larvae, and helminths, posing numerous risks to human health.

According to survey statistics from pig farms with over 1000 pigs, on average, one pig consumes 15-60 liters of water per day. The average wastewater volume is 25 liters/pig. Additionally, the amount of manure from market hogs is estimated at 2.7 kg/hog/day , which is not separated but discharged along with pen cleaning water into the biogas digester.

Currently, most pig farms do not collect and treat solid waste separately. Pig manure, leftover feed, urine, and cleaning water are all treated in a biogas digester. This results in very high wastewater pollution concentrations, with COD ~6000mg/l and Ammonia ~1200mg/l.

Analysis results from the Hanoi Institute of Environmental Technology in 2012 at several pig farms in the Northern region show that pig farm wastewater has COD, Nitrogen, Ammonia, and SS concentrations many times higher than the permitted wastewater standards.

Wastewater composition at some pig farms in the northern region

	pH	T0C	COD (mg/l)	T-N (mg/l)	N-NH4+ (mg/l)	T-P (mg/l)	SS (mg/l)
Vinh Phuc	7.32	29	4590	967.3	870	295	9520
Hung Yen	7.87	30.5	3584	202	158	54.9	1880
Thai Binh	7.3	30	2575	425	425	102	800
Hanoi	7.5	32	7219	247	237	120	3200

(Hanoi Institute of Environmental Technology)

However, the characteristics of pig farm wastewater vary significantly depending on the farming method and facility management (such as whether solid waste and wastewater are separated), and the specific conditions of each province. These conditions have a significant impact on the scale of treatment and make maintaining the treatment system difficult and costly.

III. Livestock Wastewater Treatment Technology

3.1 Disadvantages of current treatment technologies

Currently, many livestock wastewater treatment technologies are applied in Vietnam, including composting, biogas technology, biological ponds, etc., where biogas helps control odors, reduce pollutant content in wastewater, and can be used as fuel.

However, practical implementation shows that these technologies still have serious shortcomings, leading to high costs and failing to ensure long-term effectiveness.

1

Clogging & Costly Operation

• The system is constantly overloaded, with pipes frequently clogged by waste and scale buildup.
• Requires the use of many nutrient-supplying chemicals and additional expensive investments like flaring towers or gas recovery systems for power generation.

2

Air Pollution

• Biogas ponds and anaerobic tanks generate large amounts of greenhouse gases (Methane) and foul odors, directly affecting the living environment and surrounding areas.
• To comply with regulations, the project owner needs to invest further in an off-gas treatment system

3

Fails to Meet New Standards

Although they can treat organic pollution, old systems struggle to completely remove Nitrogen and Phosphorus, failing to meet the discharge standards of QCVN 62-MT:2025/BTNMT because high pollutant concentrations make it difficult to control the microbial treatment process in practice

Space-Saving – No Biogas Ponds Needed – Effluent Meets Grade A Standard

Some construction photos of a pig farm wastewater treatment project