1、 The hazards of pig farm wastewater

The discharge of manure from aquaculture farms causes serious pollution of surface water, groundwater, soil, and ambient air, directly affecting people's health. Untreated manure contains a large amount of pollutants. If this organic wastewater is directly discharged or washed into rivers, lakes, and reservoirs with rainwater, it will consume a large amount of dissolved oxygen in the water, causing the water to turn black and odorous, resulting in water pollution.

Fecal wastewater contains a large amount of nutrients such as N and P, which is one of the important reasons for eutrophication of water bodies. Discharging it into fish ponds and rivers gradually leads to the death of aquatic organisms sensitive to organic pollution, and in severe cases, the loss of functional use of fish ponds and rivers.

The long-term infiltration of aquaculture wastewater into the ground increases the concentration of nitrate or nitrite nitrogen in the groundwater, reduces the dissolved oxygen content in the groundwater, and increases the amount of toxic components, leading to deterioration of water quality and seriously endangering the water quality of surrounding domestic use. High concentration sewage can also cause soil pore blockage, resulting in decreased soil permeability, compaction, and salinization, seriously reducing soil quality, and even damaging crops, causing crop growth obstruction or death.

2、 Treatment ideas for pig farm wastewater

The wastewater discharged from pig farms belongs to organic wastewater, which has the best anaerobic fermentation effect. However, the treated wastewater has not yet reached the optimal standard and cannot be directly discharged. Moderate use in farmland and fish ponds is an excellent nutrient solution. Therefore, the sewage treatment of pig farms must be considered from a combination of biology and ecology, which is the most economical and effective way for the mutual promotion and development of breeding and animal husbandry. At present, the treatment methods for large-scale pig farm manure at home and abroad mainly include two categories: comprehensive utilization and treatment to meet emission standards. Comprehensive utilization is the sustainable development path of biomass energy through multi-level utilization, creating ecological agriculture, and ensuring harmonious coexistence between agriculture and the environment. After treatment, it can be discharged to various places such as fish ponds, farmland, or orchards within the daily allowable emission concentration range, in order to minimize environmental pollution to the greatest extent possible.

3、 Pre treatment methods for pig farm wastewater

Regardless of the process and measures taken to treat wastewater from pig farms, certain pretreatment methods should be adopted. The use of pretreatment methods can reduce the load of wastewater pollutants in subsequent treatment steps, while preventing large solids or debris from entering the subsequent treatment process, causing congestion or damage to the treatment equipment. For the large particle components in manure, pig farms can use solid-liquid separation technologies such as sedimentation, filtration, and centrifugation to achieve pretreatment. Common grids, sedimentation tanks, and sieves belong to this category. Sedimentation is one of the most widely used methods in wastewater treatment, which is a treatment process that allows suspended solids to naturally settle and separate from water under the action of gravity. At present, pig farms with wastewater treatment facilities on a large scale generally have 2-3 sedimentation tanks connected in series to treat manure through filtration, sedimentation, and oxidative decomposition. In addition, some mechanical filtration equipment, including automatic drum filters and centrifugal disc separators, can be used in the pretreatment steps of pig farm manure.

This article is compiled by aquaculture wastewater treatment equipment and does not represent the views of this website.