Sustainable semi-, decentralized sewage treatment - wastewater reuse, nutrient recovery and biogas production in the Delhi metropolitan area, India
Prof. h.c. Dipl.-Ing. Erhard Hoffmann
Dipl.-Geol. Miriam Leicht
Suburbs and peripheral areas of large cities, such as the capital Delhi in India, have major infrastructural problems, especially in the field of sanitation and wastewater treatment. This is one the one hand due to logistical and on the other hand due to financial problems. That’s mainly why the City Council in Delhi today is no longer automatically connecting new housing estates to the main central collector. One way to solve these problems are semi- and decentralized technical solutions. The proposed demonstration plant partly already exists (a Rotating Biological Contactor unit (RBC) with a capacity of 340 PE) and was formerly studied in the framework of the BMBF project „Analysis, Modeling and Demonstration of the Capability and Flexibility of Rotating Biological Contactors”. It was formerly bought and now assigned and transferred to the Delhi Jal Board (DJB). Up to today there was no utilization concept from the Indian side, and thus, after consulting the DJB, the plant will be involved in the proposed project. The demonstration plant will be reinstalled at the sewage treatment plant Okhla, Delhi and supplemented by additional elements. Thus the project shows research, development and demonstration purposes. Following a sustainable, modular approach, the main targets of the project are aimed at wastewater treatment (micro sieve, RBC) and disinfection (membrane technology) and reuse of the treated and disinfected wastewater (washing the buses of the “Delhi Transport Cooperation” (DTC)), as well as nutrient recovery (phosphorus and nitrogen as fertilizer) and energy production (biogas). The plant shows a modular structure, reduced development costs, little transport route for recycled water and low energy and maintenance requirements which makes this technology suitable for future semi-central wastewater treatment.