1. Principle of UV Disinfection
Ultraviolet (UV) disinfection is a physical method that destroys the DNA/RNA structure of microorganisms using UV light, rendering them unable to reproduce and causing their death.
Technical Advantages
• High-Efficiency Disinfection: Inactivates bacteria and viruses with ≥99.9% efficacy
• Chemical-free: No disinfection by-products, no secondary pollution
• Instant sterilization: No contact time required; disinfects instantly as you pass through.
• Low operating costs: low energy consumption, only 1/2-1/3 of chlorine disinfection.
2. UV Dose Calculation
UV Dose is the core parameter for measuring disinfection effectiveness, expressed in mJ/cm². Dose = UV Intensity × Exposure Time.
1. Dosage Standards
• Level A Standard: Fecal coliform ≤ 1000 CFU/L, UV dose ≥ 30 mJ/cm²
• Class B Standard: Fecal coliforms ≤ 10000 CFU/L, UV dose ≥ 20 mJ/cm²
2. Correction Factor
• UVT Correction: Domestic wastewater UVT 60-70%
• Bulb aging correction: approximately 80% intensity after 10000 hours of operation
• Sleeve fouling correction: approximately 90% transmittance
• Safety Factor: 1.2-1.5
III. Lamp Configuration Plan
1. Select Bulb Type
• Low-voltage, low-intensity lamps: 30-100W power, 10000-12000 hour lifespan
• Low-voltage, high-intensity lamp tubes: 100-300W power; suitable for medium-scale wastewater treatment
• Medium-voltage high-intensity lamps: 1-5kW power, suitable for large-scale wastewater treatment plants
2. Bulb Quantity Calculation
Calculate total power and lamp count based on flow rate, design dosage, and per-lamp power, with 10-20% spare capacity.
IV. Operation and Maintenance Guidelines
• Routine Inspection: Check lamp operation status and UV intensity
• Scheduled Maintenance: Clean the quartz sleeve quarterly and replace the lamp annually.
• Cleaning methods: Online mechanical cleaning, online chemical cleaning, offline cleaning
V. Conclusion
Ultraviolet (UV) disinfection is a highly efficient, eco-friendly technology widely used in wastewater and drinking water treatment. Shandong Zhongnan Environmental Protection Equipment Co., Ltd. provides customers with UV disinfection system design, installation, and operations & maintenance services.
About the Data and Author
Compiled by the Technical Department of Shandong Zhongnan Environmental Protection Equipment Co., Ltd. This content is derived from parameter records and common issues identified during equipment design, full-unit manufacturing, and on-site commissioning. It should not be used to replace field testing based on a single project conclusion.
Refer to standards including GB 18918 "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants," GB 8978 "Comprehensive Discharge Standard of Water Pollutants," GB/T 31962 "Water Quality Standard for Sewage Discharged into Urban Sewers," and HJ 2010 "Technical Specification for Membrane Bioreactor Wastewater Treatment Engineering." For specific projects, applicable standards shall be determined based on environmental impact assessment approval, discharge permits, and contractual agreements.
If you have questions about the parameters or selection methods in this article, pleaseContact UsAccompany with water quality test reports and operating conditions; we will provide explanations based on the specific project requirements.