On-site sodium hypochlorite generation is becoming one of the most reliable and efficient methods for producing disinfectant directly at the point of use. Instead of transporting and storing concentrated chlorine chemicals, facilities can create low-concentration sodium hypochlorite automatically using only salt, water, and electricity. This method greatly improves operational safety, eliminates complicated logistics, and ensures a steady supply of fresh disinfectant.
How the Technology Works
1. Preparation of the Brine Solution
The system starts by mixing ordinary food-grade salt with clean water to create a brine solution. The concentration is carefully controlled, usually around 2.5–3% salt content. This low-cost raw material makes the process economical and eliminates the need to handle dangerous chemicals.
2. Electrolysis Inside the Electrolyzer
The brine is then pumped into an electrolyzer, which is the heart of the system. The electrolyzer contains specially designed electrodes-typically made from durable, corrosion-resistant materials such as titanium coated with mixed metal oxides.
When electric current is applied, the following reaction takes place:
Chloride ions (Cl⁻) from the salt are drawn to the anode and oxidized into chlorine (Cl₂).
At the same time, water molecules at the cathode are reduced to form hydrogen gas and hydroxide ions (OH⁻).
The chlorine produced at the anode quickly dissolves in the water and reacts with the hydroxide ions to form sodium hypochlorite (NaOCl).
In simplified form:
NaCl + H₂O → NaOCl + H₂↑
Hydrogen is safely vented out of the system, while the sodium hypochlorite solution remains in the generator.
3. Output Concentration Between 0.6% and 0.8%
The system is engineered to produce sodium hypochlorite at a low concentration-usually between 0.6% and 0.8%, often referred to as "low-strength bleach."
This concentration is ideal for disinfection because:
It is safer to handle than commercial bleach (which is often 10–12%).
It avoids rapid degradation that high-concentration bleach experiences.
It provides strong and stable disinfection efficiency.
4. Continuous and On-Demand Production
On-site generators operate automatically and continuously. As long as salt, water, and power are available, the system keeps producing disinfectant. This ensures a steady supply, eliminates delivery delays, and guarantees the disinfectant is always fresh.
5. Better Purity and Stability Compared to Commercial Bleach
Commercial bleach degrades quickly during transportation and storage, losing active chlorine content over time-especially when exposed to heat or sunlight.
On-site generation avoids these problems because the sodium hypochlorite is used immediately after production. Fresh hypochlorite naturally has:
Higher available chlorine
Better stability
Fewer impurities
More consistent disinfection performance
This makes on-site generated disinfectant much more reliable for municipal water systems, hospitals, hotels, industrial plants, and other continuous-use environments.
Features:
Advanced Raw Material Feeding System
The on-site sodium hypochlorite generator is equipped with a highly efficient raw material feeding system designed to ensure stable operation and long-term durability. HCZHUN's patented salt feeding machine features a combination of PVC and 304 stainless steel, offering strong corrosion resistance and a negative-pressure feeding structure that makes salt delivery safer and more efficient. The system also incorporates a corrosion-resistant mechanical water replenishment valve that operates without electrical components, greatly improving stability. At the bottom of the salt dissolving tank, a patented salt filtration device ensures proper brine concentration, while a dedicated concentrated brine metering pump provides steady and independent brine supply. In addition, the dilution water pump is equipped with constant-pressure control to minimize fluctuations caused by changes in water supply pressure.
High-Performance Electrolytic System
The electrolytic section uses high-quality MAGNETO electrodes imported from well-known international brands. These electrodes are made from pure titanium and coated with MMO (Ruthenium–Iridium precious metal oxide), ensuring excellent electrochemical performance and efficient chlorine generation. The system also uses a transparent plate-tube electrolytic cell, another HCZHUN patented design, allowing operators to visually monitor the electrolysis process at any time. Multiple sensors are installed throughout the generator room to track temperature, flow, pressure, and other real-time parameters, ensuring safe and stable electrochemical reactions.
Safety-Enhanced Hydrogen Exhaust System
To guarantee safe operation, the equipment integrates a robust hydrogen management and exhaust system. A forced hydrogen exhaust fan is installed to ensure that diluted hydrogen concentration remains below 1%, meeting strict safety requirements. Wind pressure monitoring is also included in the hydrogen discharge pipeline to verify proper airflow and prevent system failures. In addition, a built-in hydrogen detector continuously monitors hydrogen levels within the equipment room. If concentrations exceed a preset safety threshold, the electrolysis unit will automatically shut down to prevent risks and protect personnel and equipment.
Intelligent and Fully Automated Control System
The system's intelligent control platform incorporates IoT-enabled bidirectional communication, allowing real-time data exchange, precise operational algorithms, and predictive monitoring of all key components. This ensures fully automated system operation with minimal human intervention. It also features automatic fault alarms and supports remote fault diagnosis to simplify maintenance. The integrated intelligent dosing module provides accurate, fully automatic dosing control based on real-time water quality and demand. Users can also monitor system performance remotely through a mobile app, enabling convenient networking, data access, and off-site management.
Cost Savings and Operational Efficiency
Cost reduction is a major driver of adoption. By producing disinfectant directly on-site, companies avoid transportation fees, storage costs, and price fluctuations of commercial bleach. Maintenance requirements are generally low, and energy consumption is highly efficient. Over time, users gain predictable budgeting and lower overall operating expenses. For municipal water plants, food processing factories, hotels, hospitals, and commercial buildings, these savings can be significant.
Typical Applications Across Industries
Wide Application in Water Purification Projects
On-site sodium hypochlorite generation systems are widely used in large and medium-sized water purification projects where stable, continuous, and safe disinfection is essential. Municipal water treatment plants rely on these systems to ensure the microbiological safety of drinking water.
Efficient Disinfection for Sewage Treatment Facilities
Sewage treatment plants also benefit significantly from this technology, especially in the tertiary disinfection stage. Sodium hypochlorite produced on-site provides strong bactericidal performance, helping facilities meet strict effluent discharge standards.
Circulating Water and Cooling Tower Applications
Circulating water systems-such as those used in industrial cooling towers, power plants, and HVAC systems-require continuous disinfection to prevent biofouling, algae growth, and Legionella contamination. On-site sodium hypochlorite generation is particularly suitable for these environments because it can run 24/7 and automatically adjust dosing levels based on water quality changes.
Industrial and Commercial Sanitation Applications
Beyond municipal and industrial water systems, on-site sodium hypochlorite generators are also used in large hotels, hospitals, shopping centers, and commercial buildings that rely on their own water treatment equipment. The technology ensures safe and reliable disinfectant production without the need to store hazardous chemicals.
Applications in Desalination and Environmental Engineering
Marine desalination plants and comprehensive environmental treatment projects also incorporate on-site hypochlorite generation as part of their disinfection strategy. These large systems benefit from the ability to generate disinfectant directly at the point of use, improving operational safety and removing the need for bulk chemical deliveries to remote or coastal locations.
