Innovative Toilet Technologies for Smart and Green Cities

For the way to a smart and green urban society, sanitation is an important concern. Currently, using toilets is neither smart nor green. Every flush of common toilets sends about 13 - 16 liters of fresh water to wastewater treatment centers. These processes require 3 – 15 kWh for treating just one cubic meter of wastewater. Another problem is the mixing of urine and feces from the source, necessitating wastewater treatment. This treatment leads to the waste of a high amount of valuable nutrients in the urine, and causes many environmental problems. Also due to common technical water supply problems such as pipe blockage, current toilet systems are not funtional in disasters or other emergency situations. However, many of these problems can be solved using smarter designs. In this study, innovative designs have been suggested for toilet systems. These designs use less or no water for reducing water consumption, apply systems such as bi-sloped conveyor belts to separate the urine and feces into two different tanks with biological digestion processes, improve flushing systems using alternative methods to reduce pipe blockage potential, and use special light and handy toilet seats for sanitation in emergency. Following these designs, new products have been made in lab scale to prove that these innovative technologies can reduce water and energy consumption, thereby taking positive steps towards building smarter and greener cities in the future.