To ensure the environmental protection of NPK fertilizer production lines, the following measures can be taken:

1. Precision fertilizer reduction and efficiency increase: Through accurate formulation and release of fertilizer formula information, increase the application ratio of formula fertilizer and special fertilizer, and reduce unreasonable nutrient input.

2. Environmental protection facilities design: In the fertilizer production line project, environmental protection facilities are included in the preliminary design to ensure that the design meets the requirements of the environmental protection design code.

3. Air pollution prevention and control: In the production process of organic fertilizer equipment, the dust generated in the feeding, mixing and packaging process is treated by the "gas hood + bag dust collector" and discharged by the high exhaust cylinder to reduce air pollution.

4. Waste water pollution prevention: Domestic sewage is treated by the septic tank before entering the park's sewage network, and finally entering the sewage treatment plant for treatment to ensure that the wastewater is discharged up to standard.

5. Prevention and control of solid waste pollution: waste packaging materials are collected and sold to waste collection stations, and domestic waste is collected and handed over to the sanitation department for centralized treatment to reduce the impact of solid waste on the environment.

6. Noise pollution prevention and control: noise reduction, isolation, elimination, absorption, sealing and other noise insulation measures are set for all types of noise sources to ensure that the factory boundary noise emission standards.

7. Green production and manufacturing program: The implementation of green production and manufacturing program aims to reduce resource consumption and pollutant emissions, improve resource utilization efficiency, ensure that the project reaches the domestic leading level, and set a benchmark for green manufacturing in the industry.

Through the above measures, we can ensure the environmental protection of the nitrogen, phosphorus and potassium fertilizer production line in the production process, reduce the impact on the environment, and achieve sustainable development.