Adaptable wind/solar powered hybrid system for household wastewater treatment

Sustainable and cost-effective water treatment systems are critical elements to developing nations. In India, the human population is escalating while the water availability is lagging behind. An adaptable, affordable, and sustainable wastewater treatment system powered by wind/solar energy is proposed based on proven theory and technology. A household in India is singled out to illustrate the workings of the proposed system, where the wastewater is recirculated through a hybrid of water purifiers powered by solar/wind energy. The system demonstrated here is specifically designed for small-scale applications, i.e., for a single household. The solar still has been divided into four stages. Partial vacuum is created inside the still so as to obtain boiling point temperatures of 70 °C, 67 °C, 62 °C and 50 °C in the four stages. Dhanbad, India 23.79°N, 86.43°E, with an average solar intensity of 850 W/m2 for 6 h a day, has been used for this study. A lumped parameter mathematical model was developed for this study. With an aperture area of 2.5 m2, the total amount of water distilled is found to be 43.3 kg/day. The system proposed is more efficient than existing systems as it is able to achieve efficiencies as high as 53%. The effect of wind speed on distillate output yield has also been discussed.