by Ravichandran Purushothaman, President, Danfoss Industries
A Billion Dollar Market
India’s wastewater plant segment is projected to stand at 4.3 billion US dollars by 2025 according to NITI Aayog. While this may seem like a massive opportunity for economic growth, one must consider the socio-environmental effects that comes with it.Spanning across the country, it is estimated that there are 920 sewage water treatment plants, and it is only set to grow in the future with the rising population. A study conducted by the integrated infrastructure finance company indicates that by the year 2051, the gross waste water generated at urban centres would be close to a whopping 120,000 mld (million litres per day). To counter these challenges, cost effective and environmentally sustainable solutions are sought by most urban municipalities within India.
Where does the waste go?
With India being an overpopulated country, the need for preserving sources of fresh water and reusing treated wastewater, especially in large urban areas is crucial for health and safety. Ecologically, the effects of poorly treated wastewater, that hit closer to home, is the Bellandur lake in the southern city of Bangalore that caught fire in 2018. On closer investigation it was found that close to 70 million gallons of untreated sewage water was found in the lake that had completely ruined the ecosystem.
Another example of untreated wastewater that caused a health crisis of cataclysmic proportions was in the city of Flint, Michigan in 2014. The reason for this crisis was the changing of water source from the sewage and water treatment plant to the Flint river. This ended up poisoning thousands of residents with lead and Legionella bacteria. It is therefore imperative for India to invest in wastewater treatment plants that not only aid in saving cost and are sustainable, but also improves the health of residents.These events give an accurate representation of a world without wastewater treatment plants and the subsequent harmful effects.
The path to efficiency
In contemporary times, technological advancements in the field of wastewater treatment plants are aligned towards being energy producers rather than energy consumers. Current methods for carbon neutrality that are undertaken by wastewater treatment plants are the production of biogas from sludge. This biogas is then used as fuel for production of electricity in multi-fuel combined heat and power plants. All wastewater treatment plants around the world run on certain basic components such as pumps, blowers, mixers, chemical dosing, and drives. The effort now is to ensure these componentsare more energy efficient to make these plants net carbon negative.
Pumps are rotating components that are electronically driven by advanced drives which once regulated accurately, as per the demand, result in net energy savings. These drive solutions are digitally controlled and monitored on a regular basis to curb large volumes of discharge constituting of industrial and domestic effluents. These drives also accurately control the use of each one of these components when required and the rpms, instead of letting them run continuously during the treatment process. Therefore, modern control algorithms essentially reduce the net consumption of energy for the whole treatment process.
Science behind sustainability
To facilitate the reuse of water in industries, Danfoss has provided technological solutions such as zero liquid discharge (ZLD) or a minimal liquid discharge (MLD) which can be the answer to the challenges faced by multiple industries that use water resources. ZLD and MLD are digitally controlled wastewater management strategies that reduce industrial wastewater to a minimum value or even down to zero by reuse of wastewater.These technologies essentially work on the use of very high-pressure pumps that have 90% efficiency.
These high-pressure pumps when combined with reverse osmosis membranes are extremely effective in removing effluents from wastewater and are even useful in conversion of sea water to energy. Furthermore, a membrane based effluent removal system is much more energy efficient as compared to traditional thermal based processes and is estimated to reduce energy consumption by around 75%. An example of this highly efficient process is the Arhus water treatment plant in Denmark by Danfoss, a leading supplier of high-pressure pumps and drives. The company’s solutions have brought down leakage in the water treatment plants to just 6% and made it 100% energy neutral. Such innovations are essential for future water treatment plants and India could gain from replicating these global best practices. Furthermore, a push towards scientific excellence can help reduce operational costs, thereby benefitting India economically and ecologically. Similar technology solutions are now being deployed in India as well.
Advanced sensing technologies
The final piece of the puzzle is the monitoring of the effluent quality and delivery of both untreated water to the plant and treated water from the plant. The current trends are the continuous monitoring of quality of the treated water using sensing technologies to ensure safety and ecological responsibility. These sensors flag a drop in the treated water quality immediately when detected and provide inputs to the digital drives that trigger corrective actions. This decreases the time for detection of issues well in advance and helps decrease down time of the treatment plant,essentially increasing overall operational efficiency.
The delivery of the treated water is then taken care of by additional sets of energy efficient drives that optimally distribute the treated water either internally or externally. These drives also control the inflow of untreated water using sewage channelization into the treatment plant with minimal energy consumed.
An equitable water conservative planet
With the combination of current technologies along with digital oversight by advanced algorithms the wastewater treatment industry is poised for transformation. This digital revolution is set to produce 40% more electricity than what is required to run the plant. These plants also produce about 2.5 Gigawatts of heat per year for district heating systems which adds up to 192% of energy produced. This energy produced by the plant would be enough for both treatment of wastewater and the distribution of treated fresh water, thereby making these wastewater treatment plants of the future carbon negative. India, which is a rapidly urbanizing nation would require such technologies of the future to meet its socio-economic, health and environmental goals.
To facilitate efficient wastewater treatment, it is imperative for the world to move towards smart and sustainable technologies. We at Danfoss India have built our wastewater management solutions around environmentally friendly and cost-efficient techniques that cater to all geographies and climates.
India is a land full of potential and opportunity. With the number of industries growing at a rapid pace and the amount of potentially toxic chemicals they could release into the nearby water channels; wastewater treatment is the need of the hour. We believe that catering to this challenge will spur jobs, churn the economy, and most importantly teach our future generation the much needed importance of recycling & reusing these resources.