How Does NaDCC Perform in Surface Water Treatment?
Surface water from lakes, rivers, ponds, and reservoirs can contain microorganisms and other substances that affect water quality. Effective disinfection is therefore an important part of surface water treatment. Sodium dichloroisocyanurate (NaDCC), also known as SDIC, is a stabilized chlorine compound that releases available chlorine in water for microbial control. A study of lake water in Malaysia provides a useful example of how NaDCC performs when applied to a natural water source.
Why Is NaDCC Used for Water Disinfection?
When water comes from a lake, river, or other natural source, controlling microorganisms is one of the first concerns in treatment. NaDCC offers a straightforward solution by releasing chlorine into the water, allowing the disinfectant to work directly on bacteria and other microorganisms.
It is also easy to handle. Unlike liquid chlorine, NaDCC can be supplied as granules or tablets, which makes storage, transportation, and dosing more convenient. This is one reason it has found applications ranging from drinking water treatment to emergency and household water disinfection.
What Happened When NaDCC Was Applied to Lake Water?
Researchers from Universiti Tun Hussein Onn Malaysia selected G3 Lake as the water source for the study. The lake is used by students for kayaking, leisure activities, and jogging, while previous observations had raised concerns about its water quality, including unpleasant odors and reports of skin irritation after contact with the water.
A water sample was collected and treated with NaDCC. The researchers then compared several water quality parameters before and after treatment.
| Parameter | Before Treatment | After Treatment | Change |
|---|---|---|---|
| pH | 5.45 | 4.74 | -0.71 |
| Dissolved Oxygen | 5.36 mg/L | 5.49 mg/L | 2.43% ↑ |
| Turbidity | 6.77 NTU | 5.75 NTU | 15.07% ↓ |
| ORP | 85.20 mV | 141.17 mV | 55.97mV ↑ |
| Electrical Conductivity | 625.67 μS/cm | 425.33 μS/cm | 32.02% ↓ |
The results show that the water changed noticeably after NaDCC treatment. Among the measured parameters, ORP showed the largest change, increasing by 65.69%, while turbidity, TDS, and electrical conductivity also decreased.
What Do the Results Tell Us About NaDCC?
The changes observed after treatment show that NaDCC had a clear effect on the water chemistry. The most notable change was the increase in ORP, which rose from 85.2 mV to 141.17 mV after treatment. ORP reflects the oxidizing conditions of water, so this change is consistent with the introduction of an oxidizing chlorine disinfectant into the system.
The reduction in turbidity, TDS, and electrical conductivity also shows that the treated water was different from the original lake water across several measured parameters. While these changes should be considered together with the characteristics of the source water, they provide useful evidence that NaDCC can actively alter water conditions during treatment.
For a chlorine disinfectant, this is important because effective treatment depends on more than simply adding a chemical to water. The disinfectant needs to release available chlorine into the system and maintain suitable conditions for it to work. The results from this lake water treatment therefore support the practical value of NaDCC as a chlorine source for surface water disinfection.
How Does Water Quality Affect Chlorine Disinfection?
The condition of the source water also affects chlorine disinfection. Turbidity and suspended particles can increase chlorine demand and make it more difficult for chlorine to reach microorganisms.
For surface water, filtration or clarification can therefore be used before disinfection to improve the condition of the water. Chlorine treatment can then provide the microbial control needed after pretreatment.
The appropriate chlorine dose and contact time should be determined according to the actual water quality and treatment requirements.
Where Does SDIC Fit in Water Treatment?
NaDCC and SDIC are two commonly used names for sodium dichloroisocyanurate. SDIC is available in different grades and forms, including anhydrous and dihydrate products. In surface water treatment, it can be used alongside filtration, clarification, and other physical treatment processes, providing the available chlorine needed for disinfection.
The Malaysian lake water study offers useful experimental evidence for this application. The measurable changes observed after treatment, together with the established chlorine chemistry of NaDCC, demonstrate why SDIC remains a practical option when reliable chlorine disinfection is required.
Conclusion
NaDCC provides a practical chlorine-based option for surface water disinfection. The Malaysian lake water study showed measurable changes in water quality after treatment, adding practical evidence to the established use of NaDCC as a source of available chlorine. With suitable pretreatment and proper dosing, SDIC can be applied across surface water, emergency, household, and other water disinfection applications.
About Us
Liuhe Chemicals is a professional manufacturer and global supplier of premium water treatment chemicals, including TCCA, SDIC, and Cyanuric Acid. Whether you require fast-dissolving granules for immediate microbial control or stabilizer tablets for long-lasting pool maintenance, we offer a comprehensive range of solutions. With decades of industry expertise, strict quality control, and a commitment to reliable supply, Liuhe supports clients worldwide across industrial, commercial, and household water treatment applications.
FAQ
Can NaDCC be used directly for surface water disinfection?
NaDCC can be used as a chlorine disinfection step for surface water, but the treatment approach should be based on the quality of the source water. Turbidity, organic matter, pH, chlorine demand, and microbial contamination can all affect disinfection performance. Where necessary, filtration or clarification can be used before chlorination, followed by appropriate NaDCC dosing and contact time.
Is SDIC suitable for different types of water treatment systems?
SDIC can be used in a range of chlorine-based water disinfection systems, including surface water, drinking water, emergency water treatment, and household applications. Its solid formulation allows it to be supplied in forms such as granules and tablets, while different SDIC grades can be selected according to the dosing method and treatment requirements.
Can NaDCC treatment eliminate all skin-irritating contaminants or organic pollutants in surface water?
While NaDCC is highly effective at inactivating bacteria, viruses, and other microorganisms, it is primarily a disinfectant rather than a comprehensive organic filter. Some complex organic compounds causing odors or skin irritations may require physical-chemical pretreatments—such as activated carbon filtration, coagulation, or flocculation—alongside NaDCC dosing to ensure complete removal.