The Green Water Capstone project is to purify and desalinate contaminated water using only green energy. This system is portable, solar powered, and simple to use. One can pour ocean water, river water, or lake water into it and come out with clean drinkable water. It was originally designed for emergency situations like being stranded at sea but can also be used as basis for clean drinking water in developing countries or as a camping purification system. Drinking unclean water can cause catastrophic health problems suchas cholera, typhoid, and amoebic and bacillary dysentery. W aterborne illness causes an estimated five million deaths per year (Gleick). The water is purified using electrolysis and desalinated with capacitive deionization. This system is self-contained, requires no outside agents, and is activated by the push of a button.
First the water goes through a course filter, removing all of the larger particles. Then the electrolysis unit basically runs and current through the water converting less than one percent of the total water to hydroxide, which kills all living bacteria it touches. R unning thisstep for 5 minutes at 12 volts and about a quarter of an amp resulted in having over 99% of the bacteria killed. Finally the water is streamed between two electrodes sandwiching activated carbon sheets. As the salt and other small metal particles ionize they get pulled to electrodes and get trapped in the carbon sheets. These are easily cleaned by reversing the polarity of the electrodes and running water through it. This repels the once attracted ions and results in a much saltier output brine. All of this is easily covered by a 30 watt panel that also charges several lithium ion batteries. Taking about 10 minutes for one gallon to complete its cycle on a sunny day the green water unit can clean about 50 gallons of water without dipping into the batteries energy stores.