Nutrient Recovery Systems for Human Urine - Ways to Realize Closed Loop Sanitation and Future Sustainable Agricultural Systems

This paper provides an overview on the concept of closed loop sanitation systems. A brief outline has been given on existing sanitation facilities in India, ways to implement ecological sanitation and retrofitting of nutrient recovery systems into existing sanitation facilities. In recent times, though India has witnessed phenomenal development in water resources, access to adequate sanitation facilities remain one of its major development issues. Urine Diversion Systems as a sustainable sanitation alternative can help India move closer in achieving such goals. Today, a new paradigm is being formed in wastewater management that focuses on what resources can be recovered from wastes rather than what constituents must be removed from it. Such a paradigm can help us develop a „closed loop fertility system‟ that can re-circulate nutrients from human beings back to agricultural fields. At present a wide research gap exists in this sector as research has been more focused on engineering better sanitation facilities. Sanitation systems could be re-designed in order to incorporate processes that simultaneously recover and recycle nutrients being flushed away. Any proposed project to implement these ideas can only be regarded successful if the agricultural trials of urine recycling provide useful data on agricultural benefits and potential savings in chemical fertilizers.