Sodium Hypochlorite (Javel NaOCl 10% – 12%) Concentration Lookup Table to Available Chlorine (ppm) & Disinfection Dosing Formulas

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In municipal waterworks, industrial wastewater disinfection basins, and cooling water circuits, accurately converting commercial Sodium Hypochlorite NaOCl 10% – 12% (Javel Solution) concentrations into g/L and ppm Available Chlorine directly governs microbial kill rates (Coliform ≤ 3,000–5,000 MPN/100 mL under QCVN 40:2025/BTNMT) and chemical consumption. With an oxidizing equivalence of 1.00 g NaOCl = 0.9525 g Cl₂ and solution specific gravity d = 1.14–1.21 kg/L, each liter of commercial 10%–12% Javel delivers 110.5 to 136.7 g of Available Chlorine (110,500 – 136,700 ppm).

Standard ZDHC compliant IBC tote storage at Loc Thien Chemical warehouse

1. Electrochemistry of “Available Chlorine” & pH-Dependent HOCl / OCl⁻ Speciation

Commercial Sodium Hypochlorite is manufactured by absorbing elemental Chlorine gas (Cl₂) into chilled Liquid Caustic Soda NaOH below 30–35 °C:

Synthesis Reaction: Cl₂ + 2NaOH → NaOCl + NaCl + H₂O (ΔH = -103 kJ/mol)
Mass Equivalence Factor: Because Cl⁺ in NaOCl (M = 74.44 g/mol) accepts 2 electrons when reducing to Cl⁻—identical to 1 molecule of Cl₂ (M = 70.91 g/mol)—1.000 g of pure NaOCl equals 70.91 ÷ 74.44 = 0.9525 g of Available Chlorine (Cl₂).

When dosed into water, NaOCl hydrolyzes into Hypochlorous Acid (HOCl) and Hypochlorite ions (OCl⁻) with dissociation constant pKa = 7.53 (at 25 °C):

Hydrolysis & Dissociation: NaOCl + H₂O ⇌ HOCl + Na⁺ + OH⁻ and HOCl ⇌ H⁺ + OCl⁻ (pKa = 7.53)

Because neutral HOCl molecules penetrate negatively charged bacterial membranes without electrostatic repulsion, HOCl is 80 to 100 times more bactericidal than OCl⁻:

Contact Basin Water `pH`	Active `HOCl` Fraction (`%`)	Weak `OCl⁻` Fraction (`%`)	Disinfection Efficiency & Operational Evaluation
`pH = 5.5`	`99.1%`	`0.9%`	Rapid germicidal action, but risk of corrosive `Cl₂` off-gassing if pH drops further.
`pH = 6.5`	`91.5%`	`8.5%`	Optimal pH zone for potable water and secondary effluent disinfection.
`pH = 7.0`	`77.3%`	`22.7%`	Standard operating target, balancing rapid bacterial kill and stability.
`pH = 7.5`	`51.7%`	`48.3%`	Germicidal speed halved; requires minimum `30-minute` contact retention time.
`pH = 8.0`	`25.3%`	`74.7%`	Majority exists as slow-acting `OCl⁻`; higher dosage required.
`pH = 9.0`	`3.3%`	`96.7%`	Poor disinfection; suitable only for textile bleaching or Cyanide (`CN⁻`) oxidation.

2. Standard Conversion Table: Javel NaOCl (6% – 12.5%) to g/L & ppm Available Chlorine

Table 1: Specific Gravity, Baume, NaOCl % w/w, and Available Chlorine (ppm) at 20 °C

Commercial Grade	Specific Gravity at `20 °C` (`d`, g/cm³)	Baume Degree (`°Be`)	Mass Concentration (`% w/w NaOCl`)	Volumetric Available Chlorine (`g Cl₂/L`)	Equivalent Available Chlorine in `ppm` (`mg Cl₂/L`)	Volume of Javel per `1 m³` Water for `1 ppm Cl₂` Dose (`mL/m³`)
Javel `6.0%` (Light Cleaning)	`1.095`	`12.6 °Be`	`6.0%`	`62.6 g/L`	`62,600 ppm`	`16.0 mL / m³`
Javel `8.0%` (General WWTP)	`1.125`	`16.1 °Be`	`8.0%`	`85.7 g/L`	`85,700 ppm`	`11.7 mL / m³`
Javel `10.0%` (Industrial Standard)	`1.160`	`20.0 °Be`	`10.0%`	`110.5 g/L`	`110,500 ppm`	`9.05 mL / m³`
Javel `11.0%` (High-Grade WWTP)	`1.178`	`21.9 °Be`	`11.0%`	`123.4 g/L`	`123,400 ppm`	`8.10 mL / m³`
Javel `12.0%` (FDI / ZDHC Grade)	`1.196`	`23.8 °Be`	`12.0%`	`136.7 g/L`	`136,700 ppm`	`7.32 mL / m³`
Javel `12.5%` (Commercial Max)	`1.206`	`24.8 °Be`	`12.5%`	`143.6 g/L`	`143,600 ppm`	`6.96 mL / m³`

3. Dosing Pump Flow Rate Formula & 2,400 m³/day WWTP Calculation Example

General Dosing Pump Setting Formula (L/h): Q_pump (L/h) = [Water Flow Q (m³/h) × Target Dose C_dose (mg/L or ppm)] ÷ Available Chlorine C_Javel (g Cl₂/L)
- Potable / Groundwater: C_dose = 1.5 – 3.0 ppm.
- Cooling Tower Recirculation: C_dose = 3.0 – 5.0 ppm.
- Secondary Biological Effluent: C_dose = 5.0 – 10.0 ppm (maintaining 0.5–1.0 mg/L Free Residual Chlorine after 30 min).

Technical Illustration (Reference Engineering Model): A central industrial wastewater plant treats Q = 2,400 m³/day (100 m³/h). Jar-test chlorine demand is 6.2 mg/L, plus a required 0.8 mg/L free residual chlorine at the outfall (C_dose = 7.0 mg/L).

Hourly Available Chlorine Demand: 100 m³/h × 7.0 g/m³ = 700 g Cl₂/h (16.8 kg Cl₂/day).

Dosing Pump Flow Rate Using Commercial Javel 10% (110.5 g Cl₂/L, d = 1.16 kg/L): Q_pump = 700 ÷ 110.5 = 6.335 L/h (152.0 L/day or 176.4 kg Javel 10%/day).

4. Preventing Chlorate Decomposition & Pump “Vapor Lock” (Air-Binding)

Above 30–35 °C or in the presence of trace transition metals (Fe, Cu, Ni), NaOCl degrades via two pathways: (1) disproportionation to inactive Chlorate (3OCl⁻ → ClO₃⁻ + 2Cl⁻), and (2) catalytic oxygen evolution (2OCl⁻ → 2Cl⁻ + O₂↑). Micro-bubbles of O₂ gas trapped inside diaphragm pump chambers compress without opening the discharge ball valve (Vapor Lock).

Mandatory Engineering Controls: Store Javel in UV-opaque HDPE/FRP tanks under shaded roofs (≤ 30 °C), design flooded suction piping below tank bottom level, and specify diaphragm dosing pumps with Auto-Degassing Valve Heads vented back to the storage tank top.

5–30-ton bulk tanker fleet of Loc Thien Chemical delivering NaOCl nationwide

5. ZDHC MRSL v3.1 Level 1 Certified Javel (NaOCl 10%–12%) Supply by Loc Thien Chemical

Loc Thien Investment Development Co., Ltd. (LOC THIEN INVESTMENT DEVELOPMENT COMPANY LIMITED — Tax ID: 0313650856) is a specialized commercial supplier and distributor of industrial chemicals in Vietnam:

Official ZDHC MRSL Version 3.1 Conformance Level 1 Credential: Javel / NaOCl (Sodium Hypochlorite) supplied by Loc Thien holds Conformance Summary Report (CSR) and Analytical Test Report No. 248162921-04 (issued 22/10/2024) by TÜV Rheinland Vietnam.
6 Strategic Warehouses (3,000+ tons/month, 5–30-ton tanker fleet): Ba Ria - Vung Tau (Phu My 1 IP), Dong Nai (Long Thanh IP), Binh Duong (Di An City), Da Nang (Hoa Khanh IP), Can Tho (Tra Noc IP), and Bac Ninh (Tien Son IP). Legal Headquarters: 452/6B Tinh Lo 10, Binh Tri Dong Ward, Binh Tan District, Ho Chi Minh City.
Quotation & Delivery SLA: Technical quotation within 15 minutes; delivery within 4 hours in inner HCMC, 24–48 hours across Southern & Mekong Delta industrial zones, and 2–3 days in Northern & Central Vietnam. Contact hotline 0979 891 929 for detailed delivery procedures.

Product Pages: Industrial Sodium Hypochlorite Javel NaOCl 10%–12% | Liquid Caustic Soda NaOH 32%–50% | Poly Aluminium Chloride PAC 31%
GHS Safety Data Sheets (MSDS): MSDS Sodium Hypochlorite NaOCl | MSDS Liquid Caustic Soda NaOH 32%
Technical Comparison: Comparing Liquid Javel (NaOCl) vs Calcium Hypochlorite (Ca(OCl)₂ 70%)
Technical Inquiry & 15-Minute Quotation: Hotline 0979 891 929 (tel:0979891929) — Email: [email protected].