With the principles of repair, reuse and reduction, a circular economy aims to reduce waste and pollution. In addition, it lays a strong emphasis on repairing natural systems and fostering regeneration. The principles of a circular economy can be enhanced by implementing efficient waste management practices. In order to achieve a circular economy in the water sector, the government has launched national programmes like the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) and the Jal Jeevan Mission. These missions consolidate efforts towards creating water-secure cities.
Phase II of AMRUT aims to provide tap water connections and universal coverage of septage services to households, among other services, with the support of central funding. Meanwhile, the Jal Jeevan Mission envisions to provide access to safe and adequate drinking water through tap connections to all households in India by 2024. This will be achieved through sustainable ways like recharge and reuse of wastewater, rainwater harvesting and water conservation.
The vision of the government is “Green Growth” which was also highlighted in the budget for financial year 2023-24. The government plans to drive growth through initiatives such as greening of fuel, farming, mobility, buildings and energy access with the aim of reducing the carbon intensity of the economy. To achieve these objectives, the government has increased the allocations to departments and programmes working towards achieving water security in the country. In the latest budget, the Drinking Water and Sanitation Department received an allocation of over Rs 672 billion while the Department of Water Resources, River Development, and Ganga Rejuvenation was allocated around Rs 190 billion. Additionally, Rs 600 billion has been allocated to the Jal Jeevan Mission.
Wastewater recovery and reuse through technologies
A circular economy is a restorative approach to production and consumption that involves redesigning, recovering and reusing products and materials to reduce their environmental impact. The goal is to eliminate wasted resources and utilise all available waste efficiently. To ensure sustainable reuse of treated wastewater, the implementation of decentralised methods of treatment is necessary. These methods, also called decentralised wastewater treatment systems, are cost-effective and include in-situ treatment technologies such as constructed wetlands, waste stabilisation ponds, and anaerobic digesters.
Various technologies have gained traction in the water sector, such as moving bed biofilm reactors, extended aeration processes, sequential batch reactors, membrane bioreactors, bio-towers, and anaerobic baffled wall reactors. For instance, 75 wetlands have been declared as Ramsar sites in India’s 23 states and union territories. The Ramsar site is a wetland of international importance under the criteria of the Ramsar Convention. Wetlands utilise aquatic plants like reeds, duckweed, naturally occurring microorganisms, and a filter bed commonly composed of sand, soils and gravel, which are effective in secondary or tertiary wastewater treatment. Furthermore, in 2022, the Ministry of Environment, Forest and Climate Change launched Mission Sahbhagita to effectively manage the network of these wetlands supporting water security. A special scheme called Amrit Dharohar has been launched in budget 2023-24 to encourage the optimal use of wetlands, which is also a critical part of the green growth component.
Several technologies are being deployed for reuse of water, especially by industries. Recently, Vedanta Aluminium, one of India’s largest producers of aluminium, deployed internet of things (IoT) based technology for cooling water analysis and an overall reduction in water consumption at its power plants in Jharsuguda. These power plants make use of a recirculating cooling system using water, and a cluster of natural draft cooling towers. The IoT technology collects real-time operational data and recommends optimum water quality parameters, thus helping in water conservation. This technology has helped deliver reduced water consumption, improve water quality, reduce scaling and corrosion, and improve other operational parameters that have led to an overall improvement in station heat rate.
Several technologies are being used in desalination plants for making seawater potable and useful for industries. State governments like Gujarat, Maharashtra, Tamil Nadu, Karnataka and Odisha have all constructed desalination plants in their respective states. Emerging solutions like zero-liquid discharge (ZLD) and low temperature thermal desalination (LTTD) have made their way into the Indian market. These technologies are based on the principles of sustainable use, efficient energy consumption and improved performance of desalination plants. ZLD-based desalination mitigates the impact of brine discharge by creating a closed loop of water flow. Meanwhile, LTTD utilises the temperature difference to produce potable water by evaporating the surface seawater at low pressures and condensing the resultant fresh vapour with deep sea cold water.
The exploration of ZLD has been undertaken by a few companies in India such as Aquatech Systems Asia Private Limited, Hubert Enviro Care Systems Private Limited and IDE Technologies India Private Limited. They have used the technology of thermal evaporation, crystallisation and concentrators to implement ZLD solutions in various projects.
Further, the in-situ treatment of sewage has gained traction in India. With the launch of N-treat, a sustainable technology by the Society for Innovation and Entrepreneurship at IIT-Bombay, the Brihanmumbai Municipal Corporation (BMC) is preventing sludge and sewage, from 25 stormwater drains between Bandra and Dahisar, from flowing into the seawater. This technology is a seven-stage process of treatment that uses gates, silt, traps, screens, a curtain of coconut fibres for filtration, and sodium hypochlorite for disinfection. Furthermore, this technology is a cost-effective solution that does not need manual pumping, resulting in savings on electricity, maintenance, and overall cost. It lowers the requirement for additional space as it is installed in the nullah channels on the site itself. Going forward, BMC has planned to leverage this technology for a collective water flow of around 0.11 million kilolitres per day.
The government is undertaking many advanced digital initiatives in the water sector. It is also encouraging private sector participation in the sector. The Ministry of Housing and Urban Affairs, on September 9, 2022, announced the India Water Pitch-Pilot-Scale Start-Up Challenge to address challenges in the urban water sector while identifying viable technological and business innovations. A financial support of up to Rs 2 million each is being provided to the selected startups for work in the fields of water supply and water management, among others.
Water Vision 2047
The Government of India is taking significant steps to achieve water security, with the Water Vision 2047 expected to be a major contributor to the country’s development. The state governments’ efforts towards water conservation are also expected to help in achieving collective water security goals.
India is projected to surpass the harvestable component of water resources soon, and the central government is working towards overcoming this challenge. One of its initiatives is to efficiently recycle and reuse wastewater. The government’s 5P mantra, which includes political will, public financing, partnerships, public participation and persuasion for sustainability, is a key factor in achieving these goals.
India’s water requirement is expected to increase significantly, but the country lacks the necessary infrastructure for treating the wastewater being generated in the country. According to the latest updates from the Central Pollution Control Board, the country treats less than 50 per cent of the wastewater generated. Bridging the gap between demand and supply will require recycling and reusing treated wastewater, as well as adopting new technologies.