• 2025-07-22

How to Remove Selenium from Water

Core pollution control standards

Drinking water selenium concentration limit ≤ 0.05mg/L (GB 5740-2022)

Total selenium in industrial wastewater needs to be < 0.2mg/L (GB 8978-1996)

Dual process deep purification system

1. High-pressure reverse osmosis unit

Use cross-linked aromatic polyamide composite membrane (desalination rate ≥ 99.2%)

Adaptive adjustment of working pressure 4.0-6.5MPa

Pre-activated carbon adsorption tank intercepts colloidal selenium (COD_Mn reduction rate > 85%)

2. Selective ion exchange system

Strong base anion resin (exchange capacity ≥ 1.2eq/L)

Dynamic adsorption of selenate (SeO₄^2-) takes precedence over sulfate

Selenium concentration in acid-base regeneration waste liquid is concentrated to 8g/L (recyclable resource)

Key parameters for project implementation

Control links Technical measures Performance indicators

Pretreatment Multi-media filtration + micro-flocculation Turbidity stability ≤ 0.3NTU

Membrane pollution prevention and control High-frequency pulse backwash (every 2h/time) Membrane flux attenuation rate <3%/month

Resin regeneration 4%NaOH gradient elution Selenium analysis efficiency > 98.5%

System operation benefits

Water outlet guarantee:

Selenium concentration ≤ 0.005mg/L (10 times better than the national standard)

Energy consumption per ton of water treatment < 1.2kWh (RO+IX coupling process)

Operation and maintenance advantages:

Automated regeneration system reduces manual intervention by 70%

Membrane life extended to 60 months (pH value intelligent control)

Compliance certification:

Passed NSF/ANSI 58 certification

Meets HJ 1091-2020 water quality automatic monitoring standard