The Process And Procedures of The Wastewater Treatment Equipment for Aquaculture

In recent years, with the rapid development of large-scale and intensive livestock and poultry farming in China, the environmental pollution caused by livestock wastewater has become increasingly prominent. How to efficiently and economically treat livestock wastewater has become an essential issue for farming enterprises. This article will analyze the processes and workflows of livestock wastewater treatment equipment, providing readers with a clear and practical technical pathway.

Key Characteristics of Livestock Wastewater

Livestock wastewater mainly comes from barn washing water, urine, and small amounts of feed residue. It is characterized by high concentrations of organic matter, high suspended solids, high ammonia nitrogen content, and large fluctuations in water quality and flow. If discharged directly without proper treatment, it can easily cause severe pollution to surrounding soil, water bodies, and air. Therefore, selecting a mature and stable set of treatment equipment and processes is not only a necessary requirement for environmental compliance but also an important guarantee for sustainable enterprise development.

Core Treatment Processes

Currently, the widely adopted livestock wastewater treatment process in the industry generally combines solid-liquid separation, anaerobic fermentation, aerobic biochemical treatment, and advanced treatment. Each step is interconnected, forming a complete purification chain.

I. Solid-Liquid Separation

Solid-liquid separation is the first step in the treatment process and is key to reducing the load on subsequent treatment units. Livestock wastewater first passes through equipment such as screens, sieves, or screw press separators to effectively intercept and separate large suspended solids and manure residues. The separated solid fraction can be composted to produce organic fertilizer, achieving resource utilization. The liquid fraction then moves to the next stage for further treatment.

II. Anaerobic Fermentation

After solid-liquid separation, the wastewater enters an anaerobic reactor (such as UASB, IC, anaerobic tank, etc.). In an oxygen-free environment, anaerobic microorganisms decompose organic matter in the wastewater and convert it into biogas (mainly methane). This process not only significantly reduces the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of the wastewater but also produces biogas that can be used for power generation or heating, providing additional energy benefits for the enterprise.

III. Aerobic Biochemical Treatment

The effluent from anaerobic treatment still contains certain amounts of organic pollutants and ammonia nitrogen, requiring further treatment through an aerobic biochemical system. Common aerobic processes include A/O (anoxic/aerobic), A²/O, and MBR (membrane bioreactor) . By supplying oxygen through aeration, aerobic microorganisms decompose residual organic matter into carbon dioxide and water while efficiently removing ammonia nitrogen and total nitrogen through nitrification and denitrification, significantly purifying the water quality.

IV. Advanced Treatment and Disinfection

After biochemical treatment, the effluent usually requires advanced treatment to further remove suspended solids, phosphorus, and trace pollutants. Common advanced treatment units include coagulation sedimentation, filtration (sand filters, carbon filters), advanced oxidation, and disinfection using ultraviolet or chlorine dioxide. The final effluent quality can meet the national Discharge Standard of Pollutants for Livestock and Poultry Breeding (GB 18596-2001) or stricter local discharge and reuse requirements.

Intelligent Equipment Enhances Operational Efficiency

With the development of automation and the Internet of Things, modern livestock wastewater treatment equipment has been upgraded toward intelligent and integrated systems. The application of PLC automatic control systems, online water quality monitoring instruments, and remote operation and maintenance platforms makes equipment operation more stable and simpler to manage. Operators can view equipment status, water quality indicators, and operational reports in real time via mobile phones or computers, promptly adjust operating parameters, effectively reducing labor costs and operational risks.

Resource Utilization Becomes a Trend

Against the backdrop of the "dual carbon" goals, livestock wastewater treatment is no longer limited to "compliant discharge" but is gradually shifting toward "resource utilization." In addition to the aforementioned biogas recovery and solid manure composting, the treated effluent that meets standards can also be used for landscaping irrigation, barn washing, and surrounding farmland irrigation, forming a virtuous cycle model of "turning wastewater into resources and creating benefits through pollution control."

Selection Recommendations

When selecting wastewater treatment equipment, farming enterprises should consider the following factors:

- Type and scale of farming: Different livestock species and farming densities result in significant variations in wastewater volume and quality;

- Discharge standard requirements: Clarify whether national direct discharge standards, irrigation standards, or reuse standards apply;

- Site conditions and investment budget: Reasonably choose between integrated equipment or civil engineering systems, balancing investment and operating costs;

-Operation and maintenance capabilities: Prioritize equipment suppliers with a high degree of automation and reliable after-sales service.

Conclusion

Livestock wastewater treatment is not only a mandatory requirement of environmental policies but also an important lever for the farming industry to achieve green transformation and enhance overall efficiency. A scientifically designed set of treatment equipment and processes can help enterprises achieve stable compliance, reduce operating costs, and promote resource recovery. As environmental protection technologies continue to advance, livestock wastewater will transform from a "treatment burden" into a "source of value," injecting new momentum into the sustainable development of the industry.