Green Desalination

Water testing

A few weeks ago we covered research published in the Society of Petroleum Engineers’ Journal of Petroleum Technology that laid out the possibilities of mining rare earth minerals from Produced Water, a byproduct of oil and gas production. This week we delve into a company that’s betting on the profitability of another toxic byproduct: Desalination brine. The combination of high operational costs, environmental impact, and the logistical challenges associated with brine disposal has limited the widespread adoption of desalination technology, especially in regions where cheaper alternatives are available. The surge in desalination as a solution to global water shortages has brought about environmental concerns, particularly regarding the energy-intensive processes involved and the disposal of brine byproducts.  
 
However, a pioneering initiative by the startup Capture6 is set to redefine the narrative by integrating carbon capture technology with seawater desalination efforts, promising a sustainable future for both water supply and carbon reduction. Desalination plants, crucial for supplying fresh water in drought-prone regions, face criticism for their environmental impact, notably the production of brine—a toxic byproduct harmful to marine ecosystems—and significant energy consumption contributing to greenhouse gas emissions. The challenge is twofold: supplying fresh water sustainably and mitigating the carbon footprint of such essential operations. Capture6’s venture, dubbed Project Octopus, presents an innovative approach to these challenges. The project, to be piloted in South Korea, aims to capture carbon dioxide from the air using brine from desalination processes. This not only offers a method to reduce the carbon footprint but also tackles the issue of brine disposal by turning it into a resource for carbon sequestration. Furthermore, the process yields an additional supply of fresh water, addressing the water scarcity problem head-on. 

Project Octopus leverages a liquid sorbent derived from the salt in desalination brine to react with atmospheric CO2, producing a stable, limestone-like compound that securely locks away the carbon. This synergy between desalination and direct air capture (DAC) technology could revolutionize how industries perceive and manage their waste, transforming it from an environmental liability into a valuable asset in the fight against climate change. Despite the potential benefits, the energy requirements for DAC and desalination are considerable, with current operations largely dependent on fossil fuels. The environmental viability of such projects hinges on advances in energy efficiency and the transition to renewable energy sources to power these processes. Critics and researchers alike emphasize the importance of ensuring that the net impact of integrated facilities like Project Octopus is a reduction in overall emissions and not merely a redistribution of environmental burdens. 

The ambition of Capture6, supported by collaborations with South Korean water utility K-water and wastewater treatment company BKT, reflects a growing recognition of the need for multidisciplinary solutions to climate and water challenges. While the pilot project’s scale is modest, its aim to expand significantly by 2026 illustrates the potential for scalable solutions that can have a meaningful impact on carbon reduction and water reclamation. Capture6’s innovative integration of carbon capture with desalination waste treatment stands as a beacon of how technology can bridge the gap between industrial necessities and environmental stewardship. As this and similar projects progress, they offer hope for sustainable practices that can simultaneously address the urgent needs for clean water and carbon reduction. For water treatment professionals, this represents a burgeoning field ripe with opportunities for innovation, collaboration, and leadership in environmental conservation. 

ResourcesWaterWorldThe Verge

One Man’s Trash is a Literal Goldmine

Oil rig

The old trope of “One man’s trash is another man’s treasure” is usually reserved for things like antique furniture on the side of the road or perhaps an old Marantz record player at an estate sale. However invaluable treasure is lurking in a substance long considered to be a nuisance among oil and gas producers. Recent research spearheaded by Dr. Hamidreza Samouei at Texas A&M University has brought into focus an unexpected resource in wastewater management — the potential to mine valuable minerals and metals from produced water, the wastewater brought to the surface along with oil and gas during drilling which often contains dissolved minerals, salts, and other chemicals. This revelation could reshape our approach to water treatment and resource recovery, presenting both opportunities and challenges for the industry. 

Produced water, often seen as a relatively useless and dangerous waste byproduct in oil and gas operations, is rich in minerals and elements. Samouei’s research, highlighted in the Society of Petroleum Engineers’ Journal of Petroleum Technology, reveals that produced water contains nearly every element in the periodic table, including critical minerals like lithium, rubidium, cesium, and gallium, vital for advancing technology industries. More common minerals like sodium and potassium are also abundant, offering lucrative prospects for recovery and use in various industries. 

The primary challenge in tapping into this resource is the cost of treating vast volumes of produced water, which is traditionally viewed as waste and disposed of through subsurface injections. The global annual volume of produced water exceeds 240 billion barrels, with Texas alone accounting for a significant portion. The perception of produced water as a waste product, rather than a resource, poses a significant barrier to exploring its potential. 

Samouei proposes a novel approach using CO2 desalination to mine these minerals. This groundbreaking technique involves a series of filtration methods, including ultrafiltration, nanofiltration, and reverse osmosis, to extract valuable minerals in stages before treating the water for other uses. This process not only offers an environmentally friendly solution to deal with produced water but also turns it into a source of revenue. 

Despite the potential, significant research and development are needed to make this process commercially viable. Currently, government and private funding for mineral recovery is focused on more traditional sources, like the sea floor or even asteroids. Dr. Samouei’s research aims to redirect this focus closer to home, highlighting the economic and environmental benefits of mining produced water. 

Transforming the oil and gas industry’s view of produced water from a waste product to a valuable resource requires a shift in perception and investment. Dr. Samouei envisions a future where produced water serves as a key player in the industry’s mining operations, providing essential minerals for various sectors and contributing positively to environmental sustainability. 

The potential of mining minerals from produced water offers a dual benefit — addressing the environmental challenge of wastewater management while unlocking a new source of valuable minerals. As research progresses and perceptions shift, this approach could revolutionize the way we view and utilize produced water. For water treatment professionals, this presents an exciting frontier, one that promises not only to tackle waste management challenges but also to contribute to a circular economy, where every drop of water and its hidden minerals are optimally used. 

Resources: Water OnlineNeo Water treatmentIWA Publishing

California and Arizona Propose Converting Wastewater to Drinking Water, but How Do End Consumers Feel?

drinking water

Last week in a significant move, California water regulators have approved regulations allowing local water agencies to recycle wastewater directly into tap water after extensive treatment. Similarly, the Arizona Department of Environmental Quality has proposed plans to convert treated wastewater into purified drinking water for their residents. This shift towards embracing recycled wastewater comes at a time when freshwater resources are increasingly strained by population growth and environmental factors in the Western United States. However, the success of such initiatives hinges on a critical factor: public perception. 

Public attitude towards drinking recycled wastewater presents a complex picture. A 2015 survey from the University of Pennsylvania indicated a divided stance among Americans, with only 38% willing to try treated wastewater, and 13% refusing to even consider it. This reluctance is often rooted in the “yuck factor,” a natural aversion to the water’s origin. However, educating the public about the rigorous purification process can mitigate this hesitancy. 

Geographical contexts also influence public willingness. A 2013 poll by The Guardian revealed that 63% of its environmentally conscious readership would consider drinking treated wastewater. Research by Nemeroff et al. further delved into preferences for specific treatment processes, underscoring the public’s desire for transparency and thorough purification methods, such as multi-stage filtration and boiling. In California, a 2016 survey by Xylem Inc. showed a more positive outlook, with 90% of respondents open to drinking “purified water” from treated sewage. This change in terminology plays a crucial role in overcoming psychological barriers and emphasizes the importance of effective communication strategies in reshaping public perception. 

As water scarcity becomes a more pressing issue, the environmental benefits of water reuse are gaining recognition. Ongoing research and technological advancements in treatment processes are likely to bolster public confidence in the safety and purity of recycled water. Additionally, societal values are evolving, with a growing emphasis on sustainable and responsible water use. 

Effective communication and education are paramount in altering public perceptions. Discussing the science behind wastewater treatment, emphasizing quality control measures, and presenting recycled water as a sustainable solution are key strategies. Case studies from communities successfully using recycled water can further demonstrate its viability and normalcy. 

The evolving public perception of recycled wastewater is crucial if its implementation as a sustainable water resource is to be taken seriously. As California and Arizona take significant steps towards integrating recycled water into their water supply systems, the focus turns to public acceptance. With the increasing urgency of water scarcity challenges in these states, the role of recycled water in ensuring population stability can’t be understated.  

Sources: Research GateThe GuardianXylem

Modern Contaminants Require Modern Solutions

Water Sample

Pharmaceuticals, personal care products, microplastics, and per- and polyfluoroalkyl substances (PFAS) have become the new frontier of contaminants that traditional treatment methods often fail to fully address, and the detection and removal of these substances are paramount for protecting public health and preserving environmental integrity. 

Emerging contaminants, which include pharmaceuticals, personal care products, microplastics, and PFAS, are often found in trace amounts in water sources. Pharmaceuticals enter waterways through human excretion and improper disposal, while personal care products wash off into sewage systems. Microplastics, derived from the breakdown of larger plastic items and products like cosmetics, pose a significant challenge due to their minute size. PFAS, often referred to as “forever chemicals” due to their persistence, are used in a variety of industrial and consumer products and have been linked to numerous health issues. 

Traditional water treatment systems, designed to handle well-known pollutants like pathogens and heavy metals, often struggle to effectively remove these complex and resilient contaminants. Pharmaceuticals, with their intricate molecular structures, and microplastics, with their tiny size, often bypass standard treatment processes. PFAS compounds, resistant to heat, water, and oil, present a particular challenge due to their chemical stability and persistence. 

The role of enhanced analytical techniques in water treatment has become increasingly significant, especially in the context of emerging contaminants. Advanced methods, such as mass spectrometry, are now pivotal in the accurate identification and quantification of these contaminants, including PFAS, in water sources. These sophisticated techniques offer a higher degree of sensitivity and specificity compared to traditional testing methods, enabling water treatment professionals to detect even trace amounts of harmful substances and make informed decisions about treatment processes. 

Advanced Oxidation Processes (AOPs) are gaining traction as a promising solution for degrading complex organic compounds commonly found in pharmaceuticals and personal care products. These processes, which include techniques like ozonation and photocatalysis, involve the generation of highly reactive species capable of breaking down pollutants into simpler, less harmful compounds. AOPs are particularly effective against contaminants that are resistant to conventional treatment methods, making them a valuable tool in the modern water treatment arsenal. 

In the realm of emerging contaminants, membrane technology has emerged as a key player. Techniques such as nanofiltration and reverse osmosis are proving effective in addressing challenges posed by microplastics and PFAS. These membrane-based methods work by filtering out these minute particles and significantly reducing the concentrations of PFAS in water. Their ability to provide a physical barrier and selectively remove contaminants from water makes them an essential component of advanced water treatment processes, especially in scenarios where traditional filtration methods fall short. 

The regulatory landscape for emerging contaminants like PFAS is still evolving. There is a pressing need for comprehensive guidelines and standards that reflect the latest scientific understanding of these contaminants and their potential health impacts. The presence of emerging contaminants such as pharmaceuticals, personal care products, microplastics, and PFAS in water sources is a growing concern that requires immediate and innovative responses. Advancements in detection methods and treatment technologies are essential in tackling these challenges. Equally important is the development of regulatory frameworks that address these contaminants effectively. For water treatment professionals, staying informed and adaptable is crucial in this evolving landscape, where safeguarding public health and the environment is of paramount importance. 

Nanotech in Water Treatment: Revolutionizing Wastewater Purification

Nanotechnology concept

In the quest for more efficient and effective water treatment solutions, the emerging field of nanotechnology presents a promising frontier. Among the most intriguing developments are micromotors, microscopic self-propelled devices with the potential to transform wastewater purification processes. As water treatment professionals, understanding the capabilities and challenges of this innovative technology is essential for envisioning the future of water treatment. 

Nanorobotics is an emerging field of science and engineering that deals with the design, construction, and operation of robots at the nanoscale. This means that nanorobots are machines or devices that are incredibly small, measuring just a few nanometers in size. For comparison, a human hair is about 75,000 nanometers wide. 

Micromotors are tiny engines, typically a few micrometers in size, that can autonomously navigate through water. Their propulsion is often derived from chemical reactions within the motor, using materials such as metals, polymers, or composites. This self-propulsion is key to their functionality, allowing them to move against water currents and reach areas that are usually hard to access by conventional means. 

The primary appeal of micromotors in wastewater treatment lies in their ability to target specific pollutants. Engineered to bind, absorb, or degrade contaminants, these motors can effectively remove heavy metals, organic compounds, and even pathogens from water. Their enhanced mobility ensures a more thorough and efficient purification process compared to static systems. Moreover, some micromotors are designed with catalytic surfaces, enabling them to initiate chemical reactions that break down pollutants. 

The introduction of micromotors into water treatment offers several advantages over traditional methods. Their small size and autonomous movement allow for targeted treatment of contaminants, leading to reduced processing times and minimizing secondary pollution. However, several challenges must be addressed before micromotors can be widely used in municipal water treatment plants.  

Scalability, recovery and reusability, cost-effectiveness, and environmental safety are all critical factors that need to be considered. Ongoing research is focused on optimizing micromotor design and functionality to ensure they are effective, environmentally safe, and cost-efficient. Collaborations between nanotechnology experts, environmental engineers, and water treatment professionals are essential in advancing this promising technology. 

Micromotors offer a glimpse into the future of water treatment, where nanotechnology plays a pivotal role. Treatment professionals should stay abreast of these developments and contribute to the discourse on their feasibility and integration into the existing system. While challenges remain, the potential of micromotors to enhance the efficiency and effectiveness of wastewater purification is undeniable, heralding a new era in water treatment technology.