One researcher is delivering a vision for smarter, energy-positive pumps in wastewater treatment, advancing sustainability and global growth opportunities for the pump industry.
“I love the environment, and I love water,” said Dr Haoran Duan, a senior lecturer at the University of New South Wales Sydney (UNSW). “I like to see dirty water turning into clean water. That’s a natural driving force for me to study environmental engineering and my love for nature.”
Dr Duan is originally from China and has a PhD from the University of Queensland. His passion for wastewater treatment has carried him to a leading role at UNSW Sydney. Dr Duan is at the forefront of innovative wastewater treatment technologies that minimise environmental impact.
Dr Duan’s work goes beyond clean water, encompassing solutions to complex challenges in emission reduction, nutrient recovery, and sustainability in urban water management. His research combines environmental engineering fundamentals with advanced data science tools like deep learning to model and manage greenhouse gas emissions in wastewater systems. This area is of growing interest for industries that rely on extensive water handling and purification processes, including those in the pump sector.
Pumping up a sustainable future
Achieving global carbon reduction targets requires a transformation in wastewater treatment, an energy-intensive process that contributes to greenhouse gas emissions yet plays a critical role in sustainable water management.
“While current technologies are widely adopted, they are far from optimised for today’s climate goals,” said Dr Duan. “Wastewater treatment itself is energy-intensive.”
His work focuses on reducing the energy footprint of these processes, making them more profitable and environmentally sustainable without relying solely on regulatory pressure. Dr Duan’s approach aims to make wastewater treatment self-sustaining and “not just driven by policy.”
Advanced pumps and other energy-efficient technologies that drive wastewater processes toward a net-zero, energy-positive future are vital to this transition. Pumps, essential components in moving and treating large volumes of water, offer significant potential for improvement. Optimising pump efficiency directly reduces energy consumption, while innovations in recovery technologies allow facilities to harvest biogas and other resources from the wastewater itself, transforming treatment plants from energy consumers into resource recovery hubs.
Challenges for pumps in wastewater
Pumps are essential workhorses in the wastewater industry. They move wastewater from households and enterprises to treatment plants and circulate it through various treatment stages. Pumps are everywhere in wastewater management, from transporting wastewater to providing the essential aeration that drives natural biological processes within treatment systems. The evolving demands for net-zero emissions and energy efficiency present new challenges and opportunities for pump technology in this sector, mainly as wastewater utilities increasingly aim to achieve ambitious sustainability goals.
Wastewater treatment relies on aerobic and anaerobic biological processes to clean and purify water. Pumps facilitate these processes by delivering the necessary flow, mixing, and aeration levels.
“Essentially, the wastewater treatment process is just an engineered solution of natural processes,” said Dr. Duan. “We are using engineered approaches to facilitate the aerobic process, to facilitate the anaerobic process. Aeration, for example, is particularly energy-intensive, and maintaining the right levels is key to both treatment efficacy and controlling greenhouse gas emissions.”
With the rise of climate commitments, utilities in Australia and worldwide are increasingly pledging to reach net-zero emissions within the coming decade. This goal adds pressure to optimise pump performance and integrate more intelligent control systems. Many Australian utilities, for instance, aim to achieve net-zero emissions as early as 2025, requiring better energy management and sophisticated process controls to reduce emissions and improve energy recovery. The challenge is to ensure that pumps are not merely passively controlled by existing supervisory control and data acquisition (SCADA) systems but actively integrated as intelligent components in the treatment process.
“Pumps are controlling many parameters such as hydraulic retention time, sludge retention time, and dissolved oxygen levels,” said Dr Duan.
Smarter pumps
This push for smarter pumps has implications for the entire wastewater treatment infrastructure. Beyond their traditional roles, next-generation pumps could interact directly with process models, sensors, and data systems, enabling real-time adjustments that optimise energy efficiency and emissions reduction.
Dr. Duan and his colleague Professor Bruce Bing-Jie Ni are exploring mathematical models that enhance process control, and their results are promising. One previous collaborative study between the University of Queensland and SA Water reduced greenhouse gas emissions by controlling the air pump. The changes to the air pump looked specifically at dissolved oxygen levels, showing how precise pump control can contribute to emission mitigation efforts.
However, this evolution toward “smart” pumping requires pumps to respond to complex wastewater treatment processes’ complex variables. Dr. Duan envisions a future where pumps become actively engaged in wastewater control, adjusting automatically based on real-time data rather than passively executing preset commands.
“The pump industry or pump itself should be more actively engaged in such control,” he said. “Future pumps might dynamically regulate flow and aeration in response to changing conditions within the treatment process.
Managing nitrous oxide emissions
Nitrous oxide (N₂O) emissions pose a significant challenge for the wastewater treatment industry due to their potent impact on climate change. Although nitrous oxide makes up only about 5 per cent of global greenhouse gas emissions, it can account for as much as 50-80 per cent of a wastewater treatment plant’s carbon footprint due to its high global warming potential.
Through advanced control and integration, pumps can substantially reduce nitrous oxide emissions. By adjusting flow rates, mixing intensities, and dissolved oxygen levels, smart pumps can help optimise the aeration process, potentially lowering N₂O emissions.
“Advanced control is needed to reduce nitrous oxide,” Dr Duan said. “The gas’s emission pathway is difficult to manage, and the challenge lies in finding control strategies that limit its release without compromising treatment efficiency.”
One promising approach is to integrate pumps with real-time monitoring systems and intelligent process controls that adjust operations based on the microbial activity influencing N₂O production. By modulating aeration based on real-time data, pumps can help maintain oxygen levels that minimise the specific microbial pathways known to produce N₂O. This type of control is more feasible now due to recent advancements in digital technology and data-driven solutions that enable pumps to respond dynamically to changing treatment conditions.
Smart pumps can enable better control over hydraulic retention time (HRT) and sludge retention time (SRT) in treatment plants. By optimising these variables, plants can improve the efficiency of nitrogen removal processes and potentially reduce conditions that lead to higher N₂O emissions.
While traditional pumps execute commands based on set parameters, next-generation smart pumps can adjust operations continuously to minimise energy use and emissions, making the entire wastewater treatment process more sustainable and cost-effective.
Opportunities for the pump industry
Dr Duan sees many exciting opportunities for the pump industry in Australia, particularly in taking a leading role in addressing international needs. He recently participated in a research trip to Indonesia thanks to the University of Technology Sydney (UTS).
“There’s a lot of potential for pump manufacturers to enter a range of emerging markets, such as Indonesia,” he said. “During the trip, I discovered that only around twenty per cent of Indonesia’s population is connected to sewer infrastructure. They have a bold plan of increasing that portion to a significantly higher level in the next decades, and pumps could be central to this transformation.”
Australia’s established role in providing equipment and expertise to Indonesian treatment facilities makes the opportunity for the Australian pump industry clear. “What can the Australian pump industry do there?” he asked. “There is enormous potential for Australian pump manufacturers to adapt their designs to meet local climate and economic conditions.”
Other countries in the region, such as the Pacific Island nations, represent an underserved market for reliable wastewater management technology. These areas often lack centralised treatment systems, leading to sanitation and public health challenges. For Dr Duan, this is where Australian pump expertise could make a meaningful impact.
“A lot of meaningful work needs to be done in these regions, where many systems are either poorly, unsafely managed or are treated on-site in ways that lack rigorous safety standards,” he said. “By creating adaptable, cost-effective pump solutions, the industry could expand the application to those emerging markets, addressing essential needs while building new business opportunities.”
Within Australia, the focus shifts to developing the “next generation” of pumps that integrate more sophisticated control systems and improve energy efficiency. Dr Duan believes there is potential in incorporating the pumps into the control or making the pump more energy efficient. This aligns with the increasing demand for intelligent systems in wastewater treatment, which can reduce energy consumption, adapt to real-time data, and contribute to the sector’s net-zero goals. By investing in advanced technology, Australian manufacturers can continue to lead the market and offer high-value solutions domestically and abroad.
An energy-positive future
Dr Duan emphasises the importance of shifting from an energy-intensive model to an energy-positive and environmentally sustainable one in envisioning a sustainable future for the wastewater industry.
“Wastewater treatment is really like a foundational pillar of modern society,” he said. “Despite its essential role, the industry still carries a significant carbon footprint and relies heavily on energy. This dependence strains the grid and contributes to ongoing environmental issues. I believe in a future where wastewater treatment minimises its energy consumption and produces more energy than it uses.”
According to Dr Duan, the key lies in harnessing the chemical energy embedded within wastewater.
“This energy is often overlooked, but it offers a powerful opportunity for transformation,” said Dr Duan. “By optimising treatment processes, wastewater facilities can convert organic materials into energy, turning the plants into energy-positive assets for their managers.”
Dr Duan and his team at the University of Queensland have already demonstrated that this vision is achievable. They have proven that wastewater treatment can generate surplus energy when efficiently managed.
He was recently involved in a global research project that sought to find new pathways for advanced resource recovery from waste. The team found that there are many emerging technologies for transforming waste into high-value commodities, including the recovery of cellulose, biopolymers, and proteins from waste. By properly utilising the right pump technology, these materials could be extracted downstream to create value for wastewater facilities, thereby increasing economic sustainability.
Beyond energy positivity, Dr Duan also stresses the importance of achieving net-zero carbon emissions. This dual goal—minimising energy consumption and offsetting unavoidable emissions—represents the next frontier in sustainable wastewater management. To reach this objective, the industry must reduce its emissions and explore solutions like carbon sequestration, which captures and stores carbon, offsetting the impact of necessary operations.
Dr Duan believes an energy-positive, net-zero wastewater treatment industry would be transformative. This would make these facilities economically attractive and environmentally sustainable. By achieving this vision, wastewater plants could support broader societal goals for sustainability, contributing to climate change mitigation and resource efficiency.
“The future I see for wastewater treatment is not just to reduce energy use, but to become an energy-positive process and a net-zero emitter.”
