Pilot 10 – Nitrate removal using IEMB reactor

Location: Chennai (Tamil Nadu)
Pilot Leaders: BGU/IITM
Pilot Status: One pilot module with a capacity 2 m3/day was installed at IIT Madras campus sewage treatment plant (STP) in January 2022 and been monitored since the installation. Automation of the first pilot module was finished recently and now it is running completely automated. Second pilot module will be installed in a municipal STP at Nesepakkam, Chennai by 15th August 2022.

Water challenge in this location: Tamil Nadu is a drought prone area where it is difficult for residents to get sufficient drinking water. Secondary wastewater is considered today a promising source for potable applications, but nevertheless there is a need for additional treatment steps to overcome the social stigma of using this source for potable use. For this purpose, it is stored in water bodies, followed by treating to meet the stringent drinking water standards During the surface water recharging, nitrate removal to a sufficiently low level is required to avoid the eutrophication and further toxification of the water.

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;
  • 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;
  • More energy efficiency compared to other existing methods as no external energy is required for the separation process.

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

Scope of replication/upscaling across India: Treated wastewater has a great potential for reuse as a drinking water source. Currently, membrane processes such as reverse osmosis (RO) are used for treating wastewater for drinking purposes which results in a lot of reject and high maintenance costs. Hence, such a system can be used as an add on units to any existing wastewater treatment plant with excess nitrate and nitrite levels.

Main outcomes: Increase in the reuse potential of treated wastewater, cope up with increasing drinking water demand and solution to prevent to eutrophication of the water bodies.

Public deliverables: Pilot scale system, performance report and standard operating procedure (SOP).

Other public materials: Technological details.

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

Location: Burhanpur (Madhya Pradesh)
Pilot Leaders: CENTA/CEMDS/NITIE

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.

Pilot 8 – Ultrasonic treatment of sludge

Location: Kharagpur (West Bengal)
Pilot Leaders: TU Delft/IITKGP
Pilot Status: In operation.

Water challenges in this location: As IIT Kharagpur is located in a water stressed area, there is no provision of septage management that exist in India and sludge form the septic tank is haphazardly discharged on ground creating a source for surface and groundwater contamination. This proposed technology once successfully demonstrated, shall offer a hygienic solution to the septage management and can be replicated for upliftment of the living condition of the people.

Benefits of the technology: The technology will deliver a solution towards sludge management by lowering the residual organic matter in the sludge, decreasing the pathogen content and reducing the bulking of sludge by destroying filamentous microorganisms. Further, this technology is also expected to reduce refractory organics and potentially organic micropollutants in the treated effluent, such as healthcare products and this would reduce the risk of bio assimilation while reusing treated water. Ultrasonic pre-treatment of sludge will provide better disintegration of sludge which can be further used in anaerobic digestion for enhanced biodegradability and recovery of methane or VFA. An existing sludge digester of 2 cubic metres capacity (demonstrated in Saraswati project earlier) will be used for methane recovery from the disintegrated sludge1. Combined with the acidifying digester and the production of photoheterotrophic biomass, we expect the ultrasound disintegration and disinfection will give boost to the utilization potential of municipal sewage sludge.

Potential for India: Effluent decontamination and management, as well as sewage and bio-sludge management, are increasingly in demand due to India’s rapid industrial progress and population rise. The emergence of persistent pollutants in the sewage stream is a serious concern in the Indian context. Additionally, groundwater contamination of partially/untreated sludge and sewage also diminishes the arable land capacity in the locality. Treatment schemes have to be integrated with the treatment of the xenobiotic compounds in addendum to the conventional treatment of sewage/sludge. Therefore, this technology has a great potential to help solving those water challenges across India.

Scope for replication/up scaling across India: The proposed device is designed using easily sourced, tried and tested technology components. Device fabrication, both for pilot plant and for industrial scale, uses indigenously available techniques and equipment. Thus, the potential for cost savings for India is significant, compared to sourcing intellectual property, technology and equipment from overseas for sludge management and decontamination plants, as well as potentially waste-water recovery plants.

Main outcomes:

  1. The disinfected sludge can be applied as soil conditioner
  2. Ultrasonicated sludge can also be added as a co-substrate in the anaerobic digestion

Pilot 7 – Cambi sludge digestion

Location: Roorkee(Uttarakhand)
Pilot Leaders: Cambi/IITR
Pilot Status: Anaerobic Digesters operation with CAMBI pretreated sludge under variable HRTs and Organic loadings is ongoing.

Water challenge in this location: The management of waste sludge is becoming challenging in metro cities of India. The situation becomes worsened due to the unavailability of landfill area and reluctant to use by farmers. The cost of sludge management is increasing to 20-30 % of the plant operational cost. Anaerobic treatment of sludge for energy rich biogas recovery is a good option to offset the cost of sludge treatment at some extent. However, there are technical and operational difficulties obstructing the utilization of anaerobic sludge digestion method at wastewater treatment facilities. In order to fully utilize the potential of anaerobic digestion, higher gas yield, one of the most successful pre-treatment system is thermal hydrolysis by CAMBI. By providing Cambi pre-treatment process, more than double digester loading can be achieved with shorter retention time: Reducing digester volume and construction cost, as well as saving space or increasing existing capacity.

Benefits of the technology: Key benefits are Pathogen removal (produce Class A biosolids), high biogas yield, intensification of assets (smaller digesters), better dewatering, odour control and less odour of end- product – possibly combined with post-dewatering stabilization/composting and reduction of sludge volume to be disposed. Use digestate directly without dewatering (advantage is less than half volume of digestate – high concentration of nutrients, sterilized).

Potential for India: The technology has a huge potential for India. Cambi can catalyze all inefficient and junk anaerobic digesters of India. Higher methane and high-quality pathogen free digestate can be focal advantage.

Scope of replication/upscaling across India: As sludge treatment market in India is in nascent stage, Cambi can start THP equipment in India. The potentiality of the knowledge obtained in this research project for the valorization in the Indian industries is high.

Main outcomes: Best optimised HRT conditions for effective enhancement of methane generation via thermal hydrolysis in the context of Indian Sludge.

Pilot 6 – Anaerobic digestion with electrically conductive biofilter

Location: Kharagpur (West Bengal)
Pilot Leaders: CENTA/IITKGP
Pilot Status: Pilot Status: Pilot is ready, operation will start after receiving EC media from CENTA

Water challenge in this location: IIT Kharagpur campus and nearby states are facing water challenges where people are mostly relying on groundwater source for meeting the water demand. Also, the sanitary infrastructure in this part of country is extremely poor and most of the people are relying on septic tank for treatment of black water and effluent of the septic tank is released in the environment, leading to pollution of surface and groundwater. Hence affordable solutions need to be demonstrated for sustainable decentralized black water treatment for minimizing the water pollution and protection of public health.

Benefits of the technology: The electroconductive biofilter provides the following benefits: Simple operation, robust design, low space requirements, less energy consumption (apart from pumping if required) and zero production of sludge. The electroconductive biofilter will be followed by sand filtration (providing SS and turbidity removal) and disinfection by means of UV –lamps and electrodisinfection (low energy requirements; on site generation, no handling and storage of chemicals; low generation of trihalomethanes). Solar panels will be employed for energy supply in the disinfection unit; thus, increasing the long-term sustainability of the proposed treatment plant.

Potential for India: This system can either be used as secondary or tertiary treatment as an add-on to existing treatment plants, or in combination with e.g. an UASB reactor as in this pilot for complete treatment of blackwater. As outlined earlier, there is a high need of simple and robust wastewater treatment system and therefore this system has a high potential for application in India.

Scope of replication/upscaling across India: As the technology will be locally constructed and implemented as a post treatment of an existing UASB reactor (which also was locally built as part of the Saraswati project) there is a great potential for replication and up-scaling of both the combined package of UASB reactor and post treatment as proposed in this pilot, and the post treatment as an add-on to existing blackwater treatment plants.

Main outcomes: Reuse of the final effluent obtained for irrigation, gardening, flushing, etc.

Pilot 5 – Anaerobic digestion with photoheterotrophic bioreactor

Location: Kharagpur (West Bengal)
Pilot Leaders: TU Delft/IITKGP
Pilot Status: Fabrication and installation in last phase

Water challenges in this location: The intensive use of groundwater in the region heavily affects the groundwater table. The river water procurement incurs high pumping expenditures in terms of energy expenses, manpower & machinery, and capital establishment. The total treatment cost of fresh water used on campus premises is around 25 INR per cubic metres. Depleting groundwater and water resources in and around the region calls for attention towards recycling and reuse of treated water. This can help remediating this critical situation and moving towards a sustainable future by attempting to divert fresh water for domestic uses. After successful demonstration of this technology, similar models can be adopted in across the state where the scarce sanitation infrastructure results in pollution of surface water bodies and groundwater. This unfavourably leads to high expenses on public health care and severe reduction of man-hours and societal productivity. A sustainable solution for black water treatment needs to be demonstrated to provide a healthy living condition for the mass.

Benefits of the technology: The composite process is attractive by combining production of VFA from organic matter via mixed-culture fermentation and production of a protein-rich photoheterotrophic biomass that can be valorised as fertilizer. The benefits of this attractive environmental biotechnology are multiple. It thrives on the implementation of anaerobic organisms, therefore suppressing aeration and minimizing energy costs, resulting in a full biological removal of nutrients from the wastewater. Overall, the technology will result in treatment of blackwater, full biological nutrients removal, pathogens inactivation, recovery of a high-yield and protein-rich biomass as fertilizer, and recovery of water for reuse, while protecting the environment and human health.

Potential for India: The treatment scheme proposed for this pilot uses minimum energy input and also focuses on resource recovery through a very basic innovative design, which can be constructed easily using local resources. It therefore has a lot of potential in terms of application.

Scope for replication/upscaling across India: The ability to implement this technology at a decentralised household level without much cost implication (by use of existing septic tank after certain minor modifications) and lesser footprint on land makes it more adoptable for upscaling in India. The proposition of resource recovery from sludge as fertilizers and reuse of water with limited, but dedicated manual intervention also increases the suitability of this technology for scaling up, both at household community level as well as for centralised treatment facility.

Main outcomes:

  1. Biological nutrients removal
  2. Pathogens inactivation
  3. Recovery of a high-yield and protein-rich biomass
  4. Recovery of treated wastewater for reuse

Pilot 4 – RBC followed by sandfilter

Location: Mumbai (Maharashtra)
Pilot Leaders: CENTA/NITIE

Water challenge in this location: The principal water challenges are related with: (i) scarcity of water as the water resources are far away from the city and demand-supply gap is increasing, (ii) space constraint for STP installation; need for compact plant design, (iii) Efficient sewage treatment is essential for promoting safe water reuse (iv) use of fresh water (surface and groundwater) for irrigation purposes (v) potential reuse of treated wastewater in the irrigation of current and new plots of land, thus, improving the living conditions of the population (access to safe food).

Benefits of the technology: The combination of robust and compact technologies for wastewater treatment (RBC and Sand filtration) and for water reclamation (Electrochemical disinfection) guarantees the safe reuse of the treated wastewater for irrigation purposes. Besides, the use of Electromagnetic treatment improves the physicochemical quality of the water that leads to an enhanced crops’ production. Further, as the RBC is closed tank aeration, it will be odourless. It will be able to handle shock load due to better aeration. It is cost effective. It will require minimal civil work and will be an automated process.

Potential for India: RBC is a technology that is compact and scalable and can be installed at land-constrained locations to recycle water at small scale. As outlined earlier there is in general a high demand in India for reliable and robust decentralized wastewater treatment plants.

Scope of replication and upscaling: The plant will be locally constructed with the involvement of BMC. Hence, excellent stakeholder visibility will greatly enhance the scope of replication within India.

Pilot 3 – BioKube Mars packaged wastewater treatment plant

Location: Jaipur (Rajasthan)/ Kishangarh (Rajasthan)
Pilot Leaders: BioK/MNIT; BioK/CURAJ
Pilot Status: Both the units are installed and working well.

Water challenge in this location: The location in Jaipur has medical wastewater which can be contaminated with a variety of pathogens. The location at CURAJ is typical for cities across India that have no wastewater treatment plants for smaller residential areas.

Benefits of the Technology: Mars plants are ready to install packaged wastewater treatment plant (and hence can be quickly and easily installed) that can be operated in a fully automatic and energy efficient way. Apart for the removal of phosphorous no consumables (chemicals) are required for operation. The filter media is of high quality and can be easily lifted for cleaning purpose. It further features a self-cleaning system using air lift pumps for the post settling. The system is well designed with no moving parts, which translates into very low operational expenditures. It has a guaranteed 25 year lifetime.

Potential for India: As outlined in previously, India is lacking reliable decentralized (smaller-scale) wastewater treatment plants that can meet stricter effluent standards. Hence there is a large demand for such reliable package plants. In particular in situations with clinical wastewaters reliable treatment plants are required.

Scope of replication/upscaling across India: Biokube is already cooperating with Waterneer in India which are selling the plants in India. Hence, upon successful piloting the technologies can be quickly replicated an upscaled across India.

Main outcomes: Monitoring and evaluation is in progress.