WATA®

To prevent waterborne diseases it is fundamental to deliver safe water at the point of use. The 2017 published Joint Monitoring Programme (JMP) report from WHO and UNICEF shows that recontamination occurs very often between the point of collection and the point of use and thus leads to an increase in waterborne diseases. It is thus fundamental to find a solution to enable populations to address their drinking water problem in a self-sufficient and perennial way. To respond to the need of BoP communities to have access to simple and affordable water treatment methods at the household level, WATALUX proposes a range of WATA devices (Mini-WATA^®, WATA-Standard^®, WATA-Plus^®, Midi-WATA^® and Maxi-WATA^®), and control reagents (the WataBlue^® & WataTest^®). Until today WATA^® kits have been used in over 100 countries.

The WATA^® is a handy, robust device designed specifically for the production of active chlorine through the electrolysis of salted water under conditions in developing countries. The resulting solution can be used for drinking water disinfection (1 Liter of chlorine per 4.000 Liters of contaminated water) since the strong oxidising power of the chlorine will destroy most of the pathogenic germs and the water will be drinkable after 30 minutes.

This sodium hypochlorite solution can also be used as a disinfectant for home use. The WATA^® system is extremely adaptable to meeting the disinfectant needs of larger institutions such as health facilities also. Additionally, the sodium hypochlorite solution is similar to Dakin’s solution, a neutral disinfectant, and can be used directly for cleaning wounds.

The device requires only water, salt and electricity to function. It is important to note that clear water is a requirement for both the production process and as an input for the disinfection process. For the production process, highly turbid water will interfere with the electrolysis process and the resulting solution may not be at 6g of active chlorine per liter. If the turbidity (a measure of the suspended solids in the water) of the water to be disinfected exceeds 5 units of turbidity (NTU), it could diminish the treatment’s efficiency and not guarantee adequate inactivation of microbes. If highly turbid water is the only source available, the suspended solids need to be removed, for example by (cloth) filtration, sedimentation or flocculation. The WATA^® is appropriate for urban and rural areas and foster people’s autonomy where the technology is implemented. Since the WATA^® devices need a reliable electricity supply to operate, the Mini-WATA^®, WATA-Standard^® and the WATA-Plus^® are designed to be easily powered with solar energy with dedicated solar kits supplied by WATALUX.

Preparation of the Saturated solution: The user first prepares salt water at 25g NACl/Liter. The WATA^® device needs to be immersed in the salt water and connected to a reliable source of electricity. The salt water is converted into sodium hypochlorite solution with a 6 g/L concentration of active chlorine through a process known as electrolysis. Potentially contaminated water can be made potable by adding a small dose of chlorine (5 mL chlorine per 20 L water). Despite the simplicity of operating a WATA^® device, the production of active chlorine and disinfection of potable water for a community is a responsibility, and thus requires skilled people as operators, specially trained and dedicated for that purpose.

Preparation of the solution for use of the electrolyser: Using a large syringe (50 mL), add190 mL of the saturated solution per 2 L of water to be electrolysed. Then continue to fill your container with clear water (total volume 2 L).

Testing the solution after the installation and connection of the WATA-Standard: 

WataTest^® and WataBlue^® reagents are part of the WATA^® kits and allow the user simple onsite water quality control. WataTest^® and WataBlue^® are non-toxic and inexpensive reagents which are used to measure the active chlorine concentration of sodium hypochlorite and free residual chlorine in the water, respectively. Free residual chlorine (FRC) is important because sufficient levels are required to ensure adequate inactivation of microbes and to guarantee the residual effect that chlorine has of preventing the recontamination of water during handling or consumption. Since increasing levels of FRC makes the water taste and smell unappealing, the WHO recommends a level of FRC between 0.2 and 0.5 ppm in order to strike a balance between disinfection and water taste and smell. 0.5 ppm is the level of FRC that the WHO recommends as striking the balance between effective disinfection and acceptability in terms of taste and smell. The. WataBlue^® allows the user to carry out a safe and systematic quality control of the treated drinking water to ensure that this level is reached.

Devices need to be rinsed after each procedure with clean water. Since 2018, a production controller performs 2 key assets:

• Timer: it stops the electrolysis when the process is done
• Polarity reversal: it cleans the electrodes and prevents the operator to clean the device.

Properly used, well maintained and carefully stored after each use, WATA^® devices are designed to operate for a minimum of 10,000 operating hours, meaning not less than 5 years of use. Active chlorine is very sensitive to light. It is therefore very important to store the solution produced with the WATA^® devices in closed and opaque, non-metallic recipients and label it with the production date. Place the container in a cool place, out of reach of children. Do not expose it to sunlight. The sodium hypochlorite should be used within 24 hours as the concentration of active chlorine will decline if the solution is not stabilized.

Our objective is to make safe water treatment a profitable activity for communities of developing countries. In the long run, the production and sale of chlorine should create an income generating activity for the local population and ensure their independence in water treatment. The cost for one litre of active chlorine concentrate stands at US$ 0.06.

WATA^® is more than a device, it can be combined with health education, technical training, and the creation of an economic model based on sodium hypochlorite and chlorinated water production and sales. Making safe water treatment a profitable activity while insuring autonomy.

Several dissemination models have been tested and approved in the field:

• Through health centres: The WATA^® device can produce, at a very low-cost, the large quantity of quality disinfectant needed to ensure hygiene standards in health facilities. This reduces nosocomial diseases and decreases mortality during childbirth. In addition, the sodium hypochlorite solution can be used as an effective, low-cost wound disinfectant (Dakin’s solution).
• Through economic structures (i.e. women’s groups, salesperson in kiosks, pharmacies): Direct chlorine sales or disinfection of drinking water, with subsequent sale at kiosks or home delivery, using the chlorine produced by the WATA^® device creates an income-generating activity;
• Through school structures: One WATA^® device can ensure that the school’s supply of drinking water is disinfected and be a source of disinfectants to clean floors, surfaces and latrines. They also create an opportunity for promotional and awareness activities around the themes of safe drinking water and sanitation;
• Through water user associations and water utilities: As an autonomous chlorine generator, the WATA^® device can substitute for other chlorinated products in regions where chlorine gases and powders are under embargo, as in armed conflict areas.

To appropriately implement WATA^® devices in your specific environment it is recommended to design and test the implementation, pilot it together with the users and customers, adapt and amend the dissemination strategy and the respective business model in order to scale-up and replicate the successful approaches that have been pioneered with the WATA^® devices.