Trichloroisocyanuric acid (TCCA, C₃Cl₃N₃O₃) is a potent chlorine-based disinfectant and oxidizing agent widely used in water treatment (e.g., swimming pools, drinking water, industrial cooling systems). Its compatibility with other water treatment chemicals depends on chemical stability, reactivity, and safety. Below are guidelines for mixing TCCA with common agents:
1. Compatible Agents (Safe to Mix)
These chemicals can generally be used alongside TCCA if properly dosed and dissolved separately:
(1) pH Adjusters
Sodium Carbonate (Soda Ash, Na₂CO₃)
Raises pH (TCCA works best at pH 6.5–7.5).
Sodium Bicarbonate (NaHCO₃)
Mild pH stabilizer, less aggressive than soda ash.
(2) Algaecides
Quaternary Ammonium Compounds (Quats, e.g., Benzalkonium Chloride)
Non-oxidizing algaecides; add separately to avoid chlorine depletion.
Polyquaterniums
Often used in pools; compatible if added at different times.
(3) Scale & Corrosion Inhibitors
Phosphonates (e.g., HEDP, ATMP)
Stable with chlorine at low concentrations (used in cooling towers).
Silicate-Based Inhibitors
Often compatible but test for precipitation.
(4) Flocculants/Coagulants
Polyaluminum Chloride (PAC)
Works synergistically with TCCA in wastewater treatment.
Anionic Polymers
Typically safe but avoid cationic polymers (risk of reaction).
2. Incompatible Agents (Do NOT Mix Directly)
These chemicals may react violently, lose efficacy, or produce toxic byproducts:
(1) Reducing Agents
Sodium Thiosulfate (Na₂S₂O₃)
Neutralizes chlorine; defeats TCCA’s purpose.
Sulfites/Bisulfites (e.g., NaHSO₃)
Rapidly deplete active chlorine.
(2) Ammonia & Nitrogen Compounds
Ammonium Sulfate, Urea
Forms chloramines (irritating/toxic gases).
Amines (e.g., Morpholine, Cyclohexylamine)
Risk of explosive chloramine formation.
(3) Acids
Muriatic Acid (HCl), Sulfuric Acid (H₂SO₄)
Releases toxic chlorine gas if mixed directly:
TCCA+HCl→Cl2↑+CyanuricAcid
Always pre-dilute and add separately.
(4) Other Oxidizers
Hydrogen Peroxide (H₂O₂), Potassium Monopersulfate (MPS)
Can cause uncontrolled reaction