Pilot 10 – Nitrate removal using IEMB reactor

Location: Chennai (Tamil Nadu)
Pilot Leaders: BGU/IITM

Water challenge in this location: The SBR plant at IIT Madras features a tertiary treatment system consisting of ultra-filtration and ozonation. Though anoxic system is provided in the SBR, the treated water is still having significant levels of nitrate (10-25 ppm) and nitrite (7 – 9 ppm). As a result of residual nutrients, the storage ponds are having significant amount of eutrophication. This also limits the reuse potential of the treated water. Providing a treatment system to reduce the residual nutrients will increase the treated water reusability significantly.

Benefits of the technology: Providing a treatment system that reduces the residual nitrogen-based nutrients significantly increases usability of the treated secondary and tertiary effluents. The main advantages of the technology include:

  • Bioreactor kept separate from the water treated – so no need to remove back-contamination of bacteria or organic load;
  • Simple to operate – just two process flow streams and simple controls for pH; and
  • It is flexible in that multiple modules in parallel allow increase in capacity and multiple modules in series allows to reach whatever extent of nitrate/nitrite removal that is required.

Potential for India: Greatly reduce health risks of using recycled water for irrigation and drinking – many supplies are presently compromised, and this would help to provide safe drinking and irrigation water from these supplies.

Scope of replication/upscaling across India: Nutrient pollution is a major problem in India. Most of the existing sewage treatment plants do not have the facility to remove nutrients. Hence, such a system can be used as add on units to any existing wastewater treatment plant with excess nitrate and nitrite levels. Hence there is significant potential for replication and upscaling across India.

Pilot 9 – Disinfection by means of sand pressure filter plus UV and ultrasound

Location: Burhanpur (Madhya Pradesh)

Water challenge in this location: An existing WWTP will be upgraded with a tertiary treatment.

Benefits of the technology: The aim is to provide a sustainable and robust tertiary treatment train which can be easily employed in the upgrading of obsolete existing STP or new ones. The combination of UV-LED lamps (lower energy costs) and chlorination guarantees the safe reuse of the reclaimed water (maintenance chlorination avoids the reactivation of pathogens after the UV- disinfection).

Potential for India: Decentralized wastewater treatment plants that do not provide sufficient treatment to provide safe reuse are very common across India. Therefore, there is a high potential for low cost post treatment systems to enhance effluents of existing treatment plants to be safe for reuse. In particular there is a high demand for agriculture to use safe treated wastewater as more than 60 percent of India’s irrigated agriculture is dependent on groundwater which is depleting fast in many areas. The implementation of low- cost and low O&M treatments for the reuse of treated wastewater in agriculture, such as those included in this pilot action, will significantly contribute to reducing the negative effects derived from overexploitation of conventional resources and the drought on the agricultural sector of India.

Scope of replication/upscaling across India: As the technology will be locally constructed and implemented at an existing wastewater treatment plant there is a large demand for post treatment of existing treatment plants, there is a great potential for replication and up-scaling of this technology.