The "invisible killer" in water - ammonia nitrogen, unseen pollution and an efficient removal solution

Ammonia nitrogen (NH₃-N) refers to the nitrogen present in water in the form of free ammonia (NH₃) and ammonium ions (NH₄⁺). It is an important part of the nitrogen cycle in water environments, and its main sources are biological metabolism and chemical processes.

Application fields and sources

Ammonia nitrogen is widely present in various fields such as agriculture, industry and daily life:
Agriculture:
Fertilizer application, emissions from livestock and poultry farming (accounting for more than 50% of total emissions) 
Industry:
Industrial wastewater from sectors such as fertilizer production, coking, pharmaceuticals, food processing, and textile printing and dyeing. 
Life:
The nitrogen-containing organic matter in domestic sewage decomposes (approximately 10 grams of ammonia nitrogen is produced per person per day) 
Natural: Decomposition of biological remains in water bodies and release of sediments

The "duality" of ammonia nitrogen
Beneficial aspects:
Nutritional source of aquatic plants
Moderate ammonia nitrogen in aquaculture is part of the microbial cycle
Harmful aspects:
Consumption of dissolved oxygen in water bodies:
The ammonia nitrogen oxidation process consumes a large amount of oxygen in water (1 mg of ammonia nitrogen requires 4.57 mg of oxygen for complete oxidation)
Water body eutrophication:
Promotes explosive reproduction of algae, causing "algal blooms" and "red tides"
Toxic effects:
Free ammonia has direct toxic effects on aquatic organisms (the acute poisoning concentration for fish is 0.2 - 2.0 mg/L)
Impact on water supply safety:
Increases the difficulty of water treatment and generates harmful by-products with disinfectants
Corrosion of water distribution network systems: The nitrification process produces acidic substances that corrode the water supply pipes.

Except for ammonia nitrogen resin

Strongly acidic cation exchange group (-SO₃⁻): R-SO₃H  +  NH₄⁺   ↔   R-SO₃NH₄  +  H⁺
R-SO₃Na  +  NH₄⁺   ↔   R-SO₃NH₄  +  Na⁺
Has a good affinity for ammonium ions (NH₄⁺)
Weak acidic group (-COOH): -COOH + NH₃ → -COO⁻NH₄⁺
Higher selectivity, applicable within a specific pH range
Special chelating groups:
Such as crown ethers and carboxylic acid groups, have specific recognition ability for ammonium ions
Natural zeolite modification groups: Low cost and suitable for the removal of medium to low concentrations of ammonia nitrogen.

The unique advantages of the ammonia nitrogen resin

1. High exchange capacity: up to 2.0-3.0 meq/mL, which is more than 10 times that of zeolite.
2. Excellent selectivity: the selectivity coefficient for NH₄⁺/Na⁺ is up to 10-100.
3. Wide application range: the temperature adaptation range is wide, and it maintains high efficiency within the pH range of 3-10.
4. Deep treatment: it can reduce ammonia nitrogen from 10 mg/L to below 0.1 mg/L.
5. Quick start-up: it takes effect immediately upon operation, without the need for a lengthy cultivation period of several weeks through biological methods.
6. Simple regeneration: it can be regenerated using hydrochloric acid or sulfuric acid solutions, with simple operation and less waste liquid. 7. Long service life: Can last for 3 to 5 years under normal use, with controllable operating costs.

The application of ammonia nitrogen resins
◆ Drinking water treatment: Ensure that the ammonia nitrogen in the effluent is less than 0.5 mg/L to ensure drinking water safety
◆ Municipal sewage treatment: In the advanced treatment stage, ensure stable and compliant discharge
◆ Industrial wastewater: From industries such as electronics, chemicals, pharmaceuticals, and food processing
◆ Aquaculture: Maintain low ammonia nitrogen levels in the water body and increase the stocking density ◆ Landscape water bodies: Control eutrophication and maintain water clarity