Terragon - Model WETT - Water from Waste - Wastewater Electrochemical Treatment Technology
Increasingly and in many parts of the world, clean water is difficult and costly to obtain. Unlike energy, which is available from different sources, there are no substitutes for water, which is required for all life forms.
Terragon is developing and commercializing products that will enable people to reuse their water within their habitat, or safely discharge it if reuse options are not possible.
This effort has been supported by Sustainable Development Technology Canada, the Canadian Department of Defence and the US Navy and has led to WETT™ (Wastewater Electrochemical Treatment Technology), a new wastewater treatment technology for small communities. WETT™ combines a variety of advanced treatment processes based on electrochemistry, and is a compact system that can be operated by non- technical persons. Treatment of greywater, blackwater and oily water have been extensively investigated.
Reusing water means accepting that not all applications require the same quality of water. Terragon envisages three principal classes of water, , each with its own applications, namely:
- Drinking or potable water that can be used for drinking, cooking, bathing and showers
- Utility or technical water that can be used for laundry, toilet and urinal flushing, and cleaning
- Irrigation water that can be used for plants, lawns and gardens or that can be discharged safely to the surrounding environment
WETT is an extremely compact and effective wastewater treatment system designed specifically for relatively small habitats and enterprises. It addresses the needs of this niche market by allowing the practical recovery of utility or irrigation water from wastewater (such as greywater) generated by the habitat. WETT is different, more robust and more effective than most commonly available technologies used for this purpose in small habitats. Unlike many approaches, WETT can be configured to treat all types of wastewater, including water from toilets (black water), from sinks, showers and laundry (gray water), and water contaminated with oils, solvents, heavy metals and other pollutants.
WETT uses neither micro-organisms nor chemicals to clean essentially any wastewater. WETT is a proprietary technology that uses only electrochemistry to sequentially remove both suspended and dissolved pollutants from wastewater as well as pathogens. The first stage of WETT involves treatment in a reactor making use of a process known as Electrolytic Coagulation (EC). In the EC reactor, aluminum ions and micro-bubbles are released into the wastewater. The aluminum ions coagulate the suspended pollutants while the micro-bubbles float the coagulated matter to the surface. EC followed by a proprietary filtration approach removes between 70% and 99% of pollutants in the water, including free and emulsified oils, suspended solids, pathogens and heavy metals. Depending on the wastewater source, the water generated using this approach is typically suitable for 'irrigation'. For the generation of higher quality water that can be used as 'utility water', additional treatment stages are required and these are selected based on the quality of the wastewater being treated. Additional stages may include a secondary treatment based onElectrolytic Oxidation (EO). EO uses special electrodes that generate hydroxyl radicals. These radicals are highly oxidizing agents which oxidize any dissolved organic pollutant in the partially treated wastewater. A final stage to adjust residual oxidant is often required, depending on the intended reuse and other factors.
Ultimately, WETT will generate both clean reusable water and sludge. While there are a number of alternatives for the use or disposal of the sludge, one of the most practical is its thermal destruction using MAGS. Thus, many of the small habitats that would be interested in WETT would also be interested in MAGS. Consequently, Terragon is integrating the two technologies (STEP) and will likely demonstrate WETT for habitats with approximately 150 people within the demonstrations planned for STEP.