Biocide Whitepaper
Published by ZEELCHEM™ Technical R&D
Choosing the Best Biocides for Industrial Water Treatment: Mechanisms & Rotation
Key Summary: Uncontrolled microbiological growth in cooling towers and industrial water systems leads to biofouling, loss of heat transfer, Under-Deposit Corrosion (UDC), and hazardous pathogens (Legionella). An effective biological control program requires strategic rotation between oxidizing biocides (TCCA 90) and non-oxidizing biocides (CIT/MIT, BKC, Glutaraldehyde).
1. Oxidizing vs Non-Oxidizing Biocides
Oxidizing Biocides (TCCA 90%)
Oxidizes cellular proteins and enzymes indiscriminately via hypochlorous acid (HOCl). Fast kill rate, broad-spectrum, but can be deactivated by high organic load or high pH.
Non-Oxidizing Biocides (CIT/MIT, BKC, GLUT)
Target specific metabolic pathways or physically disrupt bacterial cell walls and extracellular polysaccharide (EPS) biofilm slime layers. Stable across broad pH ranges.
2. Non-Oxidizing Biocide Portfolio Breakdown
| Biocide Formulation | Kill Mechanism | Typical Slug Dose | Primary Advantage |
|---|---|---|---|
| CIT/MIT 14% (ZEELCHEM 501) | Cellular respiration inhibition | 15–30 ppm shock | Extremely broad spectrum at low active concentration |
| BKC 50% (ZEELCHEM BKC) | Cell membrane disruption + surfactant | 50–100 ppm slug | Superior algaecide & bio-dispersant action |
| Glutaraldehyde 50% (ZEELCHEM GLUT) | Cross-linking bacterial proteins | 25–100 ppm slug | Rapid biofilm penetration, destroys Sulfate-Reducing Bacteria (SRB) |