Dingxi, a major livestock and poultry breeding area in Gansu Province, has a wide distribution of pig farms of all sizes. Pig farm wastewater is typical high-concentration organic wastewater, containing large amounts of fecal residue, organic matter, ammonia nitrogen, phosphorus compounds, and suspended solids. It is characterized by high concentration, strong odor, easy bacterial growth, and strong pollution. Many pig farmers in Dingxi often face problems such as wastewater exceeding standards, failing environmental inspections, and indiscriminate discharge of wastewater polluting soil and water sources. To operate in compliance with regulations and consistently meet wastewater discharge standards, it is necessary to select appropriate wastewater treatment processes and equipment based on local environmental standards in Dingxi and the scale of the pig farm.
DIEN wastewater treatment equipment
To effectively treat pig farm wastewater, it is essential to first understand its characteristics. Pig farm wastewater in Dingxi mainly consists of pigsty flushing water, urine, and fecal leachate. The COD, ammonia nitrogen, and total phosphorus levels far exceed those of domestic sewage, and the water quality and quantity fluctuate significantly, with noticeable differences in concentration between morning and evening, and between different seasons. Meanwhile, Dingxi is mostly mountainous farmland, and many pig farms are located near arable land and water sources. Direct discharge of wastewater can easily cause eutrophication of water bodies and soil pollution, making it a key target for local environmental inspections. Unlike industrial wastewater, livestock wastewater is more suitable for a low-cost, stable treatment model that combines pretreatment, biological treatment, and resource utilization, aligning with the local integrated farming and livestock development characteristics.
Dingxi pig farms use a mature wastewater treatment process suitable for the vast majority of local pig farms. The first step is solid-liquid separation pretreatment, where a solid-liquid separator intercepts large particles such as pig manure, residue, and flocculent matter in the wastewater, preventing clogging of subsequent equipment pipelines and siltation in the biological treatment tank. The separated dry manure can be fermented into organic fertilizer, achieving resource recycling. The pretreated wastewater enters an equalization tank to balance water quality and quantity, buffering wastewater concentration fluctuations and ensuring stable operation of subsequent systems. This is a crucial step for small pig farms to avoid equipment failure.
The second step is core biological treatment, which is also a key link in achieving wastewater standards. The industry mainstream adopts a hydrolysis acidification + A/O biological contact oxidation process, suitable for the high ammonia nitrogen and high organic matter wastewater characteristics of pig farms in Dingxi. The hydrolysis acidification tank decomposes large, recalcitrant organic molecules in the wastewater, improving its biodegradability. Subsequent anoxic and aerobic biological treatment units, through specialized microbial communities, efficiently degrade core pollutants such as COD, ammonia nitrogen, and total phosphorus in the water, purifying the wastewater at its source. This results in stable treatment effects and low operation and maintenance costs, meeting the low-cost operation and maintenance needs of the Northwest livestock industry. Some large-scale pig farms can combine this with a black membrane anaerobic pond process, suitable for the resource-based treatment model of returning wastewater to farmland in Dingxi.
DIEN wastewater treatment equipment
The third step is deep treatment and disinfection. After biochemical purification, the wastewater passes through a sedimentation tank to remove sludge, and then through a disinfection module to remove pathogens and insect eggs. The final effluent consistently meets the discharge standards for livestock and poultry wastewater. The treated wastewater can be used for farmland irrigation and farm watering, fully complying with the local environmental protection policies of integrated crop and livestock farming and the resource utilization of manure in Dingxi, achieving zero discharge, no pollution, and recyclable treatment results. The wastewater treatment for pig farms in Dingxi does not require complex processes. The core is to adapt to local water quality, climate, and environmental policies by adopting a scientific pretreatment + biochemical treatment process, and selecting appropriate equipment based on the scale of the farm. This can not only efficiently solve the problem of wastewater exceeding standards and help pig farms operate in compliance with regulations, but also realize the resource utilization of manure and reduce the environmental protection costs of farming.
