The Energy-Water Nexus: Optimizing Water Treatment for Sustainability

Every living thing, from the tiniest sapling to the new-age homo sapiens, needs water to survive. It is required in almost every sector of life- from growing food to ensuring a healthy lifestyle, everything depends on it. Living beings cannot survive without fresh water. Nevertheless, the methods used to purify water for drinking are commonly high in energy consumption. Water and energy are essential resources that help bring comfort and contribute to the development of civilization. This establishes a meaningful connection between water and energy, known as the energy-water nexus.

Comprehending this connection is essential for reaching sustainable water management practices. We can turn this interaction between water and energy into a sustainable dance by modifying water treatment methods, switching to energy-saving technologies, and incorporating renewable energy sources. This article delves into the connection between water and energy usage in water treatment and examines approaches for reducing the energy usage of treatment plants.

Every drop counts, but so does every watt:

Water treatment plants, vital for providing clear tap water, consume large amounts of energy. Each step in the process, from extracting water to treating it, depends on pumps, filters, and other methods that consume large quantities of energy. However, the hidden thirst for power has a dual impact. Excessive energy usage results in costly expenses for treatment centers, potentially resulting in higher water expenses for customers.

The release of greenhouse gases caused by burning fossil fuels in wastewater treatment plants to clean water negatively impacts the environment. So, the process designed to protect our environment (clean water) can indirectly harm it (climate change). Water treatment involves several stages, each requiring energy to function.

Water is initially taken from its origin, such as rivers, lakes, or reservoirs, using pumps that consume substantial energy. Screens or filters eliminate big debris, such as branches and leaves. Chemical additives induce small suspended particles to aggregate and create clusters known as "flocs." The chemicals themselves do not require much energy, but energy consumption increases during mixing because pumps and stirrers are often used. Further, energyintensive pumps are necessary during sedimentation to remove the settled sludge. Water is then filtered through sand or membrane filters to eliminate any remaining particles. Using extra energy is required when backwashing filters to remove built-up material.

Disinfection methods such as chlorination and ultraviolet (UV) treatment eliminate dangerous bacteria and viruses. Although chlorination uses less energy, ozone disinfection has a high energy requirement. The storage and distribution process involves storing treated water in reservoirs and then pumping it through a system of pipes to deliver it to homes and businesses. Energy is also necessary for pumping in this last phase.

Optimizing Existing Systems:

Fortunately, there are several strategies available currently for water treatment facilities to reduce their energy footprint and promote sustainability:

? Process Audits: Conduct comprehensive energy audits following industry standards. These audits will detect inefficiencies in equipment performance, highlight high-energy usage areas, and evaluate the potential for system optimization.

? Upgrade Equipment: Focus on replacing aging equipment with high efficiency models that meet relevant certifications (e.g., Energy Star, Hydraulic Institute certifications). Upgrade pumps with outdated impellers and blowers with excessive pressure drops and address filtration systems experiencing high headloss.

? Intelligent Controls: Imagine having a fancy control panel that monitors everything at the treatment plant, like a flow meter that checks water pressure and a unique gauge that tracks energy use. This is what SCADA and HMI systems do. They even work with other equipment to automatically adjust things and save energy!

? Variable Speed Drives (VFDs): VFDs precisely regulate the speed of pumps and blowers. This ensures their utmost operational efficiency and decreases energy consumption compared to fixed-speed operation. For further optimization, consider incorporating advanced VFD features like soft starts and sleep modes.

? Sequencing Batch Reactors (SBRs): SBRs are activated sludge systems with cyclical operation that offer several advantages over conventional continuous flow systems. They optimize aeration and mix cycles and thus reduce energy consumption.

? Optimization of Backwash Cycles: Backwashing filters are essential for maintaining performance, and implementing optimized backwash cycles effectively decreases the frequency and length of backwashes, leading to water and energy conservation.

Advanced Technologies: This section discusses ways to save energy at wastewater treatment plants, such as membrane bioreactors, anaerobic digestion, electrocoagulation, and microbubble aeration.

? Membrane Bioreactors (MBRs): MBRs combine biological treatment with membrane filtration to clear wastewater in one go, like super powered strainers. Because they are minuscule, they are also space savers.

? Microbubble aeration: Microbubbles have a greater surface area to volume ratio, similar to using millions of tiny bubbles instead of a few big ones for cleaning and filtering purposes. It improves oxygen transfer efficiency and uses less energy than conventional coarse bubble aeration systems. Fine bubble diffusers can generate aeration microbubbles (less than 100 microns).

? Anaerobic Digestion(waste-to-fuel): Imagine a machine that turns leftover waste from cleaning water into fuel! Anaerobic digestion does this by capturing biogas from wastewater treatment processes and utilizing it in a combined heat and power (CHP) set up to generate electricity and heat for the facility, lessening reliance on outside electricity sources and powering the treatment plant itself.

? Electrocoagulation (EC): This method uses electrical current to destabilize pollutants in water, clumping them together and floating them for easier removal. It can handle a broader spectrum of pollutants and is better for the environment compared to typical chemical coagulation techniques.

Apart from the simple solutions and advanced technologies discussed above, installing small hydropower turbines for water treatment plants near rivers or streams is also viable. This will allow the plant to harness renewable energy from gushing water and further reduce its reliance on traditional energy sources. Besides, utilizing acoustic leak detection systems to pinpoint leaks and prompt repairs can diminish the possibility of water loss and associated energy demand for additional treatment.

In essence, water treatment plants can significantly decrease energy usage, operational expenses, and environmental effects by incorporating a comprehensive strategy combining all the discussed techniques, paving the way for a more sustainable future in water treatment.

How can Aquamech help in devising sustainable water solutions?

We tackle sustainable water treatment in the below-mentioned ways:

1. Reduce, reuse, recycle: We focus on helping industries and institutions use water more efficiently. This involves treating wastewater so it can be reused for specific applications, reducing the need for freshwater consumption.

2. Minimized waste production: Our commitment to environmental responsibility is evident in our design of high-purity water systems. These systems play a crucial role in minimizing water waste during processes like pharmaceutical production by converting wastewater into cleaner effluent or potentially reusable water, thereby reducing water contamination and the need for disposal.

3. Optimization of Energy Use: Our expertise in energy-efficient solutions is at the Heart of our service offerings. Recognizing that water treatment can be energy-intensive, we design cold storage solutions that use less energy, indirectly contributing to sustainability. Our Commitment to designing and building facilities involves selecting and recommending energy-efficient treatment methods, significantly lowering the environmental impact.

4. Responsible Disposal: Drainage Solutions involves helping clients properly dispose of wastewater that can't be reused. This ensures environmentally responsible practices and prevents pollution.

5. Adoption of sustainability standards: We focus on adhering to sustainable water treatment practices and regulations, which ensures responsible water management.

Overall, we approach water treatment holistically, considering ways to reduce water usage, minimize waste, and optimize energy use in related systems.

This all contributes to a more sustainable approach to water management. For any free consultation you can get in touch with our Design Head Mr. Navdeep Singh Sethi at [email protected]