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New asphalt binder alternative is less toxic, more sustainable than conventional blend

September 18, 2023

Bio-based patch from ASU will lead to safer travels and recreation

Asphalt is primarily known for use in roadways, but it's also used to pave playgrounds, bicycle paths, running tracks and tennis and basketball courts — all platforms for activities where breathing toxic fumes can be dangerous. Outdoor use on driveways, rooftops and parking lots, especially in the Arizona sun, also can lead to toxic fume exposure.

A team from Arizona State University, led by Associate Professor Ellie Fini in the School of Sustainable Engineering and the Built Environment (SSEBE), has developed AirDuo, a new, patent-pending asphalt binder that not only diminishes toxic fumes of the overall asphalt-surfaced area, but also increases sustainability. 

But perhaps most importantly for Fini, it reduces health hazards for those exposed to asphalt-surfaced areas, especially for those performing the installation.

AirDuo's first local trial was initiated in late August as a patch in ASU's Gammage Auditorium parking lot. Frank Castro, associate director of Facility Maintenance, helped get the research out of the lab and into the parkig lot, facilitating the lab-to-market transition. On the morning of the install, the Parking and Transit Services team, led by Assistant Manager David Triana, completed the patchwork in a few hours.

Attendees of a theater production at Gammage the same night gave the patch a workout as they arrived and departed, and Castro reported to Fini the next day that the patch had “held up great.”

Fini envisions the new low-carbon, bio-based binder will ultimately be used for all asphalt paving products, not just patches.

The U.S. Department of Labor’s Occupational Safety and Health Administration notes that about a half-million workers annually are exposed to fumes from asphalt, with health effects that include headache, skin rash, fatigue, throat and eye irritation, cough and skin cancer.

Asphalt binder is the glue that holds together the stones, sand, gravel and other aggregates in asphalt pavements. The AirDuo binding mixture is composed of low-carbon, bio-based materials that are an alternative to more toxic petroleum products, also known as bitumen. Moreover, AirDuo acts as a toxicity filter for the overall product.

After the traditional blend of aggregates and binder is laid on the roadways, the stress from heat, sun, weather and traffic causes the release of breakdown products — molecules that vaporize — some of which are odorous, highly toxic or both.

“We breathe 11,000 liters of air per day,” Fini said. “But our nose isn’t smart enough to know when the air may be dangerous for our health. That new-car smell people like? That may not be good for your lungs. We run away from a smelly trash can, but the pleasant smell or fumes from certain materials can be far more toxic.”

Fini and Judith Klein-Seetharaman, a professor in both ASU’s College of Health Solutions and School of Molecular Sciences, collaborated to review literature about the health effects of various asphalt mixtures and mapped the effects on a network of biomarkers. Citing specific contaminants present in asphalt, the team discovered that all are not created equal and that different formulas have different levels of toxicity — the majority of which have not been studied comprehensively.

According to Klein-Seetharaman, there have not been sufficient studies of the long-term effects of asphalt-related toxins on the body.

“To give justice to the complexity of the problem, we need a systems-level view of the interactions between asphalt fume components and their biological targets,” Klein-Seetharaman said. "There are thousands of molecules present in asphalt, as well as thousands of biomolecular targets inside the human body that can bind to these molecules and respond to their presence with downstream biological effects, some of which can lead to adverse health outcomes.”

Fini has conducted ongoing research to investigate alternative asphalt binders, including a study on how iron-rich biochar absorbs volatile organic compounds from asphalt surfaces, and how it is both an eco-friendly and cost-effective alternative to bitumen components.

“When we use algae to make AirDuo, as we did from last year’s November harvest from ASU’s Center for Algae Technology and Innovation (AzCATI), it can be carbon negative,” said Fini, who collaborated on the algal components of the project with Peter Lammers, a research professor in SSEBE; Taylor Weiss, a Polytechnic School assistant professor; and Shuguang Deng, a professor in the School for Engineering of Matter, Transport and Energy (SEMTE).

“The use of algae in the AirDuo binder provides a critically important environmental benefit,” Lammers said. “As algal photosynthesis removes carbon dioxide from the air, the AirDuo manufacturing process retains that carbon in an improved asphalt product relative to petroleum-derived binders.” 

“We plan to scale up the process by growing algae on wastewater, thus providing an additional ecosystem service," he said of future plans for substituting algae for petroleum products in other roadway projects.

Other bio-based materials the team has used include biochar from fire-reduction efforts in California and northern Arizona. Process sustainability depends on the feedstock sourcing and, in the case of AirDuo, the use of biomass waste from forest residue, according to Fini.

“This promotes resource conservation and waste valorization, as well as enhances public health and safety — all while providing a more sustainable pavement material.”

SSEBE Professor Mahour Parast oversaw sourcing and supply chain to enable scale-up for AirDuo. DPE Materials, the team’s partner based in Yuma, brought 10, 40-pound bags of AP1 (AirDuo Paving) for the patch at Gammage.

“AirDuo represents a complete sustainability package,” Fini explained. “We are using biomass as our feedstock — it has already pulled CO2 from the air prior to harvesting. The AP1 helps create a sustainable built environment and provides reduced health risks to both asphalt workers and those using asphalt-surfaced areas.”

Fini’s lab studies showed a nearly 70% reduction in emission when AirDuo was used. While not a one-to-one translation to the field, according to Fini, it clearly illustrates toxic fume reduction. The mix also had notably less smell than any other mix made in the plant. 

The research on bitumen asphalt binder alternatives began with a 2019 grant from the National Science Foundation on algae-derived products. A grant from the U.S. Department of Agriculture with a focus on emission reduction and environmental health supported the research and also helped with the lab-to-market transition.

“Our next steps are larger projects on the ASU campus, and then perhaps in Flagstaff and Tucson. Our team invites other states and institutions to join the AP1 (AirDuo Paving) campaign and test it on their sites, too,” Fini said.

But Fini and her team are delighted ASU is leading the effort. 

“It is an Arizona-born technology inspired by Arizona’s sun and heat,” Fini said. “Arizona is ideal for growing our feedstock algae, and also a great testbed for AirDuo. With 320 days of sun in the Valley, the smell of asphalt-surfaced areas never stops.

“You can verify this the next time you get out of your car in an open parking lot in summer.”

SSEBE students and postdocs engaged with AirDuo research include Sand A A Aldagari, Abdullah Aloraini, Mohammadjavad Kazemi, Anna Melis, Masoumeh Mousavi, Albert Hung and Farideh Pahlavan.

Top photo: ASU’s Ellie Fini surveys the ASU Gammage Auditorium parking lot site where the first trial of AirDuo, a low-carbon asphalt binder, was used for a recent patch. AirDuo has the potential to be used for many asphalt paving processes, not just patches. Photo by Bobbi Ramirez/ASU

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New probes gather real-time algae information in CAP canals

June 23, 2022

Immediate information valuable for agricultural farmers

Taylor Weiss lowers the probe into the bottom of the canal and waits for the conversation to begin.

“Hey, how are you feeling today?” the probe says to the algae. “Are you happy? Or are you not?”

The answer to those questions enables Weiss and his team at the Arizona Center for Algae Technology and Innovation, or AzCATI, to detect algae blooms in real time in the canal system, information that is critical to homeowners and agricultural farmers throughout Arizona.

“The whole part of our sensor system is you can see the problems as they’re coming,” said Weiss, a senior global futures scientist at Arizona State University’s Julie Ann Wrigley Global Futures Laboratory and assistant professor in the Polytechnic School, part of the Ira A. Fulton Schools of Engineering. “It’s like a weather forecast. Just by letting people know when an event is going to hit, they can adjust.”

Through a partnership with Burge Environmental, which developed the new technology, AzCATI has a half-dozen probes testing the water in the 336 miles of the Central Arizona Project canal system, as well as Lake Pleasant.

The probes, powered by solar energy and connected to a computer terminal that sends out data like a cell phone, are essential because drought conditions brought on by climate change — “everything that could make the situation worse is now happening,” Weiss said — can create “extremely problematic” algae changes, and previously there was no way to gather immediate information.

“There was no practical way without having an army of people grabbing samples physically across 300 miles of canal,” Weiss said, adding that it’s impossible to keep algae from blooming in the CAP canals. “Not just monthly, not even weekly, but daily, to even establish a pattern. And then what tests are you going to run? Now we have a real-time potential measure of biological activity in the environment.

“Fundamentally, what we can now say with much greater confidence — is the algae growing slow? That’s because it was cold yesterday. So, it’s a cloudy day, they’re growing slow and that’s fine. Or, if they’re growing slow and we think they should be growing faster, we need to find the reason because that’s an opportunity for improvement.”

The continuous, real-time testing of the algae bloom is vital for several reasons. First, if the algae Cymbella – often called “rock snot” for its sticky, yellow, clumpy form – grows too quickly, it can reduce the efficiency of water flow. While a sticky canal may not seem like a big deal, that energy loss could instead be powering thousands of homes each year, Weiss said.

“The state of Arizona spends 4% of its annual energy on this canal,” Weiss said. “So, you start doing the math and very quickly it’s a gross inefficiency.”

It’s also important to know what type of algae is growing in the canal system. Some algae create “odor and taste issues that people drinking water don’t enjoy.”

The real-time information is also helpful to agricultural farmers, who depend on a consistent water supply from the canals.

“If they know a problem is coming, like the intakes being clogged, a problem at 9 a.m. on Monday is an easy problem to solve, while a problem at 2 a.m. on Sunday is difficult,” Weiss said. “Because we don’t have the manpower in place across a very large area, you’re ill-prepared, which means the system will be running inefficiently and it’s going to disrupt users.

“So knowing the problem and understanding how to predict it, this is algae forecasting. The hard part of our job now is we’re in the stages of taking relatively simple data and trying to break it down to something as simple as a weather forecast. Like a map where you have sensor platforms, we’ll have a number from one to five saying how bad the algae is in this region based on water flows. And if we know they’re breaking loose in one place, we can say, ‘Hey guys, in 48 hours this problem could be at your doorstep.’”

Weiss hopes the new sensor system can be used beyond the CAP canals. He said he recently met with the Mesa city council; Mesa gets approximately one-third of its water from CAP, one-third of its water from Salt River Project and one-third of its water from groundwater sources.

“We’re absolutely looking to go straight to some of the municipalities,” Weiss said. “Right now, there’s no one-stop shop to bring this puzzle together. Ultimately, for the state of Arizona, that’s what we want to develop.”

Top photo: Duane Barbano, a doctoral student in biological design, attaches a battery and telecommunications equipment to a tower railing on April 11 at Lake Pleasant. The crew, led by Assistant Professor Taylor Weiss, installed both a floating and a fixed probe network from a secure pumping station at the CAP-fed reservoir. The probes, which range throughout the 160-foot lake depth, measure the biochemical activity of the environment, especially in response to nutrients as they flow. For example, the data will show when there are algae blooms, which will allow the CAP to adjust the Valley’s delivery operations system. Photo by Charlie Leight/ASU News

Scott Bordow

Reporter , ASU News

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Zero waste water

November 30, 2021

ASU researchers see potential in wastewater

When you think about wastewater — if you do at all — you probably think of reeking, worthless sewage that you flush down the toilet or sink and never think about again. When Bruce Rittmann thinks about wastewater, he sees potential.  

Rittmann is a researcher at Arizona State University who is leading a project using the greenhouse gases produced through wastewater treatment to generate electricity, create biofuel and possibly even make ice cream — all thanks to microalgae.  

The three-year project, funded by the Department of Energy, is culminating in a six-week trial with the city of Mesa’s Northwest Water Reclamation Plant in Sloan Park near the Salt River. 

“The city of Mesa has anaerobic digesters, is located close to ASU, is always eager to try out advanced technologies, and has been a great research and development partner with our center for some years,” says Rittmann, a Regents Professor in the School of Sustainable Engineering and the Built Environment and director of the Swette Center for Environmental Biotechnology at the Biodesign Institute. 

Rittmann has been involved in research using gas-transfer membranes — the basis for this project — for 20 years and has been using this technology with microalgae for over a decade. By pairing up with the city and getting access to their anaerobic digesters, which treat wastewater, his team has been able to scale the project up massively. 

Not only does wastewater smell bad, it’s also a major problem for the environment. Wastewater treatment produces biogas made up of methane and carbon dioxide (CO2), the biggest contributors to climate change.  

Typically, wastewater treatment facilities burn the biogases they produce. This eliminates the methane, which converts to carbon dioxide in the burning process. 

“So now you're just emitting CO2. Of course, I think we're all familiar now with CO2 being a problem,” says Justin Flory, an associate director of research in ASU’s Center for Negative Carbon Emissions and project manager of the trial. “It's less of a problem than methane, but it's still a problem.” 

People are not going to stop producing wastewater. In fact, as the population grows, we’re probably only going to produce more of it. But the very problem that wastewater treatment creates could provide value instead. 

This project proposes a better solution with no burning required. The researchersThe ASU team also includes Rosa Krajmalnik-Brown, Yen-Jung Lai, Michelle Young, Zoe Frias, John McGowen, Robert Stirling and Jason Quinn, with the added support of Carole Flores. Several city of Mesa team members were instrumental in making this possible, including Tom Sheber, Roy Van Leeuwen and Jesus Mendez. take the carbon dioxide produced by treating wastewater and feed it to microalgae, which can then be turned into a variety of products. The process also takes the methane produced and generates purer biomethane, which is a high-value product. 

“It’s a great opportunity to partner with ASU to develop technologies that will help us meet our sustainability goals while ASU meets their goals of continuing to lead the world in innovation,” says Scott Bouchie, the city of Mesa’s director of environmental management and sustainability. 

Capturing greenhouse gases with green goo 

If the heart of this project is to convert greenhouse gases into useful products, microalgae is the stomach.  

Wastewater treatment at Northwest Water Reclamation Plant involves anaerobic digestors. These are large, dome-shaped reactors filled with microorganisms — like bacteria — that break down organic material in the biosolids produced as part of wastewater treatment. One output of anaerobic digestion is biogas, which is a mixture of methane and carbon dioxide.  

The water reclamation facility captures and compresses those gases for storage in tanks. Normally it is burned to generate heat, which emits carbon dioxide into the atmosphere. For the ASU project, they deliver some of that biogas to three, 270-square-foot algae ponds located near the digesters.  

The ponds were designed by staff at ASU’s Arizona Center for Algae Technology and Innovation and fabricated by students with the assistance of Everett Eustance, an assistant research scientist in the Swette Center who is also the lead researcher running the cultivation trial. 

The biogas is delivered directly through thin, hollow fibers placed directly in the ponds. The carbon dioxide diffuses through the membranes of the fibers into the water, where the microalgae consume it for their photosynthetic growth.  

The process can deliver carbon dioxide to the microalgae with nearly 100% transfer efficiency — this means that nearly all of the carbon dioxide present in the biogas is used instead of being released into the atmosphere. The carbon dioxide delivery also increases the microalgae’s growth rate and lowers the cost of its production. 

“The CO2 content of the atmosphere is too low to support high productivity, which means that delivering concentrated CO2 is one key aspect of increasing microalgae productivity and lowering the costs of the products derived from the microalgae,” Eustance says. 

What happens to the methane? Most of it goes out the end of the fibers, where it is captured for later use. Because almost all the carbon dioxide has been removed, the exiting gas is a purer form of biomethane.  

“The city of Mesa just passed a council-approved Climate Action Plan that has aspirational goals of carbon neutrality, 100% renewable energy and waste diversion of 90% by 2050,” Bouchie says. “The project we’re working on today will help us take a step towards those goals.” 

Three algae ponds at a wastewater treatment facility

Biogas captured from wastewater treatment is delivered to these three ponds, where it is used to grow algae. The ponds were designed at ASU's Arizona Center for Algae Technology and Innovation. Photo by Andy DeLisle.

Turning waste into valuable commodities 

The whole process keeps the biogases out of the atmosphere. But what can be done with the end products? 

“That enriched methane can be used to make electricity or it can run your gas stove in your house or fuel those natural gas buses that run around town,” Flory says. 

The microalgae grown from the CO2 can be used in a wide variety of products. 

“We can convert that biomass into many different things,” Flory says. “Some microalgae are high in protein and omega three fatty acids and can be used to feed animals or fish. There are even compounds in microalgae that we use today in ice cream.”  

Microalgae can also be converted into biofuels.   

“Think about how fossil fuels are created — heat and pressure underground over time converts old organic material, like plants, into fossil fuels. That takes millions or thousands of years, but there is technology being developed that can do it in minutes,” Flory says. 

The microalgae can be mashed down into a slurry and be pressured cooked until it becomes a crude biofuel. Biofuels are non-toxic and a renewable source of energy. They also create a closed cycle — the biofuel will still release some carbon dioxide, but it can be eaten by new microalgae grown to make more biofuel.  

The city of Mesa is enthusiastic about the positive financial effects this project could have on their water reclamation facilities. 

“We are grateful to have ASU’s involvement in this research project,” said Mesa City Councilmember Mark Freeman. “The possibility of reducing the plant’s operating costs by using biogas to generate electricity is an exciting prospect.” 

Going from a lab to the real world  

The researchers know that all these things are possible in theory, but can they work in practice? Scaling up from a lab using synthetic gases to a working treatment plant presents a less consistent — but more realistic — environment. Partnering with the city of Mesa is monumentally important to the scientific process, helping to identify real-world challenges and how to overcome them.  

Since this process relies on the effective growth of microalgae, the team needs to keep the same things in mind that the average plant-parent does at home. Plants need sun, water and the right climate. Algae are no different, and inconsistencies and other issues with these three things can affect how well the algae grows. 

In general, Arizona is a good location because of how much sunlight is available year-round. Even so, sunlight brings its own problems. 

“Sunlight needs to reach the bottom of the pond to be effective. If you have a very dense culture, that sunlight can’t penetrate it,” Flory says. 

This puts a limit on the amount of microalgae that can be grown in each pond. To get around this, the team has determined the optimal density for the microalgae that will still allow a sufficient amount of it to be grown.  

“Water is a rare resource in the desert, so that’s another challenge we face,” Flory says. 

Fortunately, at a wastewater reclamation plant, water is openly available, and that water can’t be used for drinking.  

Weather could further affect the microalgae’s growth. In a lab, it’s relatively easy to have a consistent environment, but outdoor weather naturally changes. 

“Algae do well in warm climates. As it starts to cool down here, the microalgae will grow slower and won’t take up as much CO2,” Flory says. 

As we edge into wintertime, the impact of the project and the products generated may slow down. Although cold weather could mean less carbon dioxide is consumed, there is still an overall decrease from what would normally be released. 

To address this concern, the team has run the trial through the end of November, utilizing strains of algae that can thrive in cooler weather. 

Looking toward the future ​​​​​​​

After this project ends, the team is hoping to conduct another trial with the city of Mesa early next year. 

The next time around, the team plans to include another waste stream that the wastewater treatment process generates. This waste stream contains leftover liquid from the anaerobic digestors that would provide necessary nutrients like nitrogen and phosphorus for the microalgae to grow — and it can be pumped directly into the microalgae ponds. 

“It would be the whole shebang. We’d be getting our nutrients from the wastewater and the CO2​​​​​​​​​​​​​​ to feed the microalgae,” Flory says. 

This would mean the project would truly be a closed cycle. Essentially every waste produced by the treatment process would be used up.  

“Innovative programs like this one could create new opportunities to improve Mesa operations on behalf of our residents,” says Mesa Mayor John Giles. “We’re really proud to be working with them on this research project, which is also another positive step toward our climate action plan goals.” 

This trial is a good jumping off point to show other cities that there’s a solution for cutting back on greenhouse gas emissions by wastewater treatment facilities.  

“Residents of Arizona see a need to really change the way we operate today,” Bouchie says. “It seems like there’s a lot of things we call waste that truly are not waste — they're resources.”  

Written by Elise Lange

Top photo: Everett Eustance, an ASU assistant research scientist, leads the algae cultivation trial at Mesa's North West Water Reclamation Facility. Photo by Andy DeLisle.

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Algae bloom may be behind mysterious California deaths

August 26, 2021

ASU algae expert explains one of the deadliest toxins on the planet

On a remote trail in California’s Sierra National Forest called the Devil’s Gulch, a family of three and their dog were recently found dead. Authorities were at a loss to explain what happened.

"I've worked in different capacities, but I've never seen a death like this," the county sheriff told the press.

It turns out the family might have been exposed to a poison deadlier than nerve gas: toxic algae, one of the deadliest toxin on the planet.

Unofficially, it is called Very Fast Death Factor. The CIA reportedly uses it in suicide pills for agents likely to be captured by the enemy. It has caused entire towns along the Italian coast to be evacuated. And it may have been the cause of a mass die-off of an African elephant herd.

Last month, the Sierra National Forest — part of the U.S. Forest Service — announced that "a high concentration of algae bloom" had been found in the Merced River.

"The Sierra National Forest (SNF) would like to inform those visitors who like to enjoy this area of the Merced River and SNF, not to swim, wade or allow their pets to enjoy the water," the agency announced.

ASU News talked to Taylor Weiss, an Arizona State University assistant professor in environmental and resource management in the Polytechnic School and a member of the Arizona Center for Algae Technology and Innovation — where research is being done to harness algae technology to produce renewable energy, food, feed and other valuable products, while performing environmental services to support a more sustainable future for society — about this deadly substance. 

Question: My first thought was, I didn't know that algae could kill.

Answer: It is among the most deadly toxins on the entire planet. If you made a list of like the top 10, VX gas-synthetic (a nerve agent) would only be one of the top 10. All the rest are held by algae. ...

The tidbit of history that people gloss over is that the CIA actually stopped issuing cyanide capsules a long time ago. But we know for a fact that U-2 pilots who flew over Russia were issued fake coins with needles in them laced with saxitoxin to kill themselves in the event of torture. So we know what they do. We know the most highly effective chemical weapons designed mimic their activities. They accomplish the same goal. They are paralytic agents that paralyze your nerves that control your skeletal muscles. They lead to your diaphragm becoming unable to move, which means you suffocate, as almost certainly what seems to have happened to this particular family on this occasion.

When (authorities) were concerned about toxic gases for mines and immediately they'd say they were looking for carbon monoxide poisoning, it's just that they died quickly and suffocated. Many of the other toxins that most of the time we pay attention to — which are liver toxin, hepatotoxins, like a poisonous mushroom — those take days or weeks usually to kill. But literally saxitoxin’s unofficial name is Very Fast Death Factor. It kills very quickly. So you should have it in the same mindset as a chemical weapon.

Q: So this family was out with their dog. Would they be next to a creek or a puddle?

A: It’s the same reason why pets die from it, especially dogs. The dogs go in the water, they swim in it and they come back with the algae sticking to their fur in particular, and then they lick it off or people wipe their hands on the dog or something like that. We had pet deaths in Arizona earlier this year from the same thing. ... Some of these compounds, they volatilize. They can literally just be off-gas in the air. So you don't need to go into the water to be exposed to it.

There were major blooms of some of these toxins off of Italy about five years ago. Entire villages were evacuated because the air was poisoning them enough that everybody was affected. These are no joke. And you don't know that they're there. They’re ephemeral, so they come and go. However, blooms are natural. The toxins are natural. But having lots of algae producing lots of the toxin, and there's certainly grades of toxins, it's difficult to keep track of. It's not very common. It’s one of these incredibly high-risk but low-probability events that just is very difficult to sort of get and stay on top of.

Q: If you were out on a hike, what would be some warning signs that it was nearby?

A: I would look to regulations on the books. So the World Health Organization issued regulations about 10 years ago on the standard by which advisories any country anywhere should basically make actions for, recreational and drinking and other uses like that. Basically, if there's a lot of algae in the water, there's a lot of chlorophyll, i.e. the algae are very active, so they'll be able to make lots. And then number three is, are they cyanobacteria? Other types of algae can be toxic, but the cyanobacteria are the most common. (Cyanobacteria is blue-green and smells like freshly cut grass.) So those three standards, basically, you keep track of them.

And so in an event where you have lots of cyanobacteria, and they're doing a lot of photosynthesis and they're there in high numbers very rapidly, you should be very concerned. We do not have federal guidelines in the United States. The problem is somewhat unequally spread between states. It means state regulators are really responsible for monitoring and enforcing things ... and so it also varies by state. Obviously in California, they do monitor areas where people come into contact with water on a more routine basis. But if it's in a more rural area, this is where we hear these stories all the time. It's basically, the water's not monitored and people, their pets or animals come into contact with it. Nobody's paying attention, and on rare occasion, these very bad things happen.

Q: So a good rule of thumb would be if you see a pool or a pond or a puddle with a lot of algae, stay away from it.

A: If a regulator has put up warning signs saying to avoid the area, follow them. ... I would take the warnings more strongly than even (what) the regulators themselves often post. There is always pushback on a recreational side. Cities don't want to declare suddenly you can't go swimming and spend summer dollars and vacation. They don't like that. And because these events can be very ephemeral, right? Maybe it's one day it's harmful, but you're killing the whole rest of the summer. There's always that conflict. So regulators will be very cautious, but they're kind of putting responsibility on you.

If there isn't an issued warning and you're out in nature and things like that, the problem is with these very toxic algae, you may not see any problems. It may appear to be free and clear water. There could be a bloom somewhere else, but just carrying the toxins downstream. ... There is no great rule of thumb, except if you don't know the water, don't trust the water. And in particular, what I would say is, in the summertime it is more likely to be cyanobacteria, so to be more cautious. This is why swimming is the bigger problem. People don't tend to swim in the water in the winter, but that's also the safer time.

Top image by Gina Janosch from Pixabay

Scott Seckel

Reporter , ASU News

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Algae engineering: A stepping stone to sustainable solutions

November 6, 2020

Among ways being explored to combine biology and engineering to remedy a range of growing global environmental problems, algae-based solutions look especially promising.

The encouraging viewpoint stems from progress in research that is revealing how the properties of algae can be harnessed to become the driving force for a slew of productive biotechnological pursuits.

Some of the research findings have been the result of efforts based at the Arizona Center for Algae Technology and Innovation, or AzCATI, embedded in the Ira A. Fulton Schools of Engineering at Arizona State University.

Algae is an abundant and widely varied group of aquatic organisms capable of producing oxygen through photosynthesis and thereby harvesting energy from sunlight to grow and produce a range of biochemicals.

That capability and related characteristics can make algae a useful component in the development of advanced systems for effectively treating wastewater, producing cleaner energy and new biofuels, reducing harmful carbon dioxide emissions and improving decontamination and pollution control techniques.

Engineers and scientists say the chemical components in algae can also strengthen materials used to build transportation systems and other public infrastructure — while sequestering carbon in the process to substantially boost the sustainability of both natural and built environments.

An essential testbed site for algae-related industries

group of students wearing green I love algae shirts

A group of recent and current student research assistants pose in their lab team T-shirts at the AzCATI facility. More than 150 ASU students have gotten valuable research experience at the Fulton Schools algae research center during its 10 years of operation, including those in degree programs in chemical engineering, human systems engineering, biochemistry and bioengineering, environmental resource management, sustainable food systems, natural resource ecology and astrophysics. Photo courtesy of AzCATI

AzCATI launched in 2010 with a multimillion-dollar investment from Science Foundation Arizona, a nonprofit with the mission of diversifying Arizona’s economy by aligning university research with the needs of industry.

The foundation’s support financed the development of several acres of algal growth ponds on ASU’s Polytechnic campus — located close to biochemical and molecular biology labs with resources available for use in AzCATI’s projects, particularly the cultivation of algal biomass for biofuels.

Before long, the center became one of the major testbeds for algae biotechnology-derived products, including nutraceuticals, biofuels, food and feed and high-value pharmaceuticals — all from algae biomass. This was possible due in large part to the Department of Energy-funded ATP3 consortium, which is designed to accelerate research and development of algae-based technologies.

“We’ve become basically the algae farmers for many public and private ventures that need to make advances in algae cultivation and productivity to reach their goals and our goals,” said John McGowen, AzCATI’s director of operations and an ASU sustainability scientist. “We collaborate with industry and academics to ‘road-test’ technology, and use data being generated by our testbed site to contribute to reducing technology risk and helping to propel the success of these enterprises.”­­­­­

The center now has longstanding working relationships with major U.S. research facilities, including the National Renewable Energy Laboratory, the Pacific Northwest National Laboratory, Los Alamos National Laboratory and Sandia National Laboratories.

“Most of the national labs don’t have access to their own outdoor testing facilities, so they can come to us,” McGowen said. “Recently, through the DOE-funded DISCOVR consortium, we’ve achieved some of the highest outdoor algae cultivation productivity rates ever.”

Expanding applications of algae research and development

people looking at algae tanks

AzCATI’s leaders say many students and others who have worked at the center have gone on to use what they learned from the experience in their careers. Professor Peter Lammers (at right) is pictured in 2017 at the center’s testbed facilities with (left to right) Nick Csakan, a former AzCATI technician now working in a large California dairy converting manure to compressed natural gas to fuel buses; Thinesh Selvaratnam, a former postdoctoral researcher from Sri Lanka, now a professor at Lamar University in Texas; and Wonkun Park, a former postdoctoral researcher who is now a professor at Sangmyung University in Seoul, South Korea. Photo by Jessica Hochreiter/ASU

AzCATI is part of ASU’s LightWorks, an accelerator that focuses on advancing solar energy generation and other sources of sustainable energy, fuels and related products. The center is also part of the School of Sustainable Engineering and the Built Environment, one of the six Fulton Schools.

Through its connection to LightWorks and the school, AzCATI has been able to draw on a broad array of engineering and science resources and expertise, helping the center attract close to $70 million from public agencies, industry and foundations — as well as partnering with startups to obtain small business innovation grants — leading to significant expansion of AzCATI’s activities during its first decade.

Over that time, the use of algae in products has notably increased. Algae is now an ingredient in foods (for humans and animals), cosmetics, nutritional supplements like omega-3 oils, antioxidants, coloring agents, dyes for fabric, sunblock lotion, printing ink, flour and paper, among many other consumer products.

Beyond those uses, algae is a key ingredient in materials essential to a variety of industries. It’s often a key component of bioconcrete, the source of many bioplastics, and a growing source of agricultural biostimulants and fertilizers. Algae is used in aquaculture as feed for fish and shrimp, naturally imparting healthy antioxidants and omega-3 oils, along with appetizing colors, that don’t come from typical soymeal.

Looking at possibilities for expanding and improving the use of algae-based processes and technology to advance not only economic interests but also the greater societal good is the main thrust of research led by the three Fulton Schools faculty members on AzCATI’s leadership team. Each is contributing to innovation in what is called the Algae-Food/Energy/Water Nexus.

Research Professor Peter Lammers studies algae from acidic hot springs, applying his knowledge of molecular biology and environmental chemistry to create large-scale carbon-foundries that will fuel the future carbon economy.

Assistant Professor Taylor Weiss concentrates on making biochemical and biophysical advances, using synthetic biology and novel sensors to create and control the production of renewable biochemicals, sustainable agricultural additives, algal biofuels and products to improve human health.

Professor Shuguang Deng utilizes chemical engineering principles to develop adsorbents, catalysts and membranes for systems and technologies providing sustainable energy, chemicals, fuels and construction materials.

Attracting support from a range of public and commercial sources

hand holding algae

Algae has myriad uses in a wide variety of industrial processes, biofuel production, food and health supplements, bioplastics, fertilizers, pollution control, waste treatment and ecosystem repair. Work at AzCATI is focusing on enhancing those uses while exploring new and impactful applications of algae-based technologies and systems. Photo courtesy of AzCATI

Research by Fulton Schools colleagues outside of AzCATI meshes with the center’s goals and helps support its ongoing projects.

Associate Professor Elham Fini is using an additive derived from algae to boost the resilience and reduce the emissions of asphalt — which is especially important in hot and sunny Arizona.

Professors Bruce Rittman and Rolf Halden’s work focuses on finding more effective methods of protecting and restoring the health of ecosystems.

In his Center for Negative Carbon Emissions, Professor Klaus Lackner is developing carbon capture technology to help pull harmful greenhouse gases out of the atmosphere.

Research capabilities in these and related areas over the years have brought AzCATI more than a dozen major projects funded by the U.S. Department of Energy, along with other projects supported by the Small Business Innovation Research programs of the U.S. Department of Agriculture and the National Institutes of Health.

Funding has also come from the Department of Energy’s Advanced Research Projects Agency-Energy, the Central Arizona Project — the aqueduct and canal system that brings water to much of central and southern Arizona — as well as numerous companies such as Xylem, a major multinational innovator in water technology.

Research collaborators rely on AzCATI’s expertise and creativity

Longtime AzCATI collaborators in industry, government agencies and research universities say the center has played an essential role in their research and development success.

Matthew Posewitz, a professor of chemistry at the Colorado School of Mines, has been in algae research field for more than 20 years and has worked on algae biofuels and related projects with support from the National Renewable Energy Laboratory and the Department of Energy.  

“Some algae technology advances were pioneered at ASU dating back decades ago,” Posewitz said, “and the people at AzCATI continue to perform that level of work. They have been consistently at the forefront of algae testbed productivity. We have always been able to rely on the competence and creativity of the people there.” 

Philip Pienkos has that same level of confidence in AzCATI’s researchers and technicians.

“I have always trusted them to do outstanding work and I always will,” said the biologist and recently retired emeritus scientist with the National Renewable Energy Lab.

His assertion is based on collaborations he was involved in with AzCATI since its early days, finding its leadership especially motivated to make breakthroughs in algae research.

“Once we decided what it was going to take to accomplish what we wanted to do, we could count on them getting the work done,” Pienkos said.

He recalls the first project he worked on with AzCATI researchers being an especially rewarding accomplishment. Together they provided the basis for a concept of an algae-based biorefinery, which led to the development of algae-based polyurethane, a plastic material with a plethora of practical uses.

Today, Pienkos is in the process of getting his own startup venture off the ground as a platform for commercializing urethane technology.

Helping to reverse direction on our unsustainable path

woman posing next to algae tanks

Madison Clar is pictured overseeing the processing of algae through a photobioreactor at the AzCATI research facilities. Clar began working at the center as an undergraduate and after earning her bachelor’s degree in applied biological sciences was hired as a staff member. She recently moved on to to a position at a cancer research institution. Clar’s path follows that of many student research assistants whose work with AzCATI has been a springboard to career opportunities. Photo courtesy of AzCATI

From a big-picture perspective, Lammers and Weiss say, solutions to the environmental threats posed by the increasing amounts of detritus — decomposing waste and debris — that is created by modern civilization lie at the nexus of AzCATI’s endeavors and related ASU research projects.

For example, conventional activated sludge treatment of municipal wastewater leads directly to 24 billion tons of carbon emitted as carbon dioxide. The AzCATI team is researching ways of using algae to turn wastewater treatment into a renewable carbon foundry that would replace petroleum as the primary feedstock for industrial carbon commodities. 

AzCATI’s leaders say that engineering algae can help society change its unsustainable course. Algae-based technologies and systems could provide alternatives to wasteful and unsustainable practices that are causing environmental deterioration.

The researchers envision such an advance enabling development of effective and economical methods to clean up the damage that has already been done, while also spurring the development of new products — along with creating new jobs to better support communities and economies in an ever-growing world.

LightWorks Director Gary Dirks, who led the effort to establish AzCATI, says the center is at the leading edge of realizing the full potential of algae-based technology “to turn what is in those waste streams into valuable products.”

Such advances can contribute to creating “more sources of fuel, food, raw materials and chemical feedstocks to improve life in the future,” Dirks said. 

Ram Pendyala, director of the School of Sustainable Engineering and the Built Environment, shares that outlook. AzCATI’s work “will lead to transformative algae-based technologies that fuel our societies and clean our environments in the years ahead,” Pendyala said.

Top photo: Research at the Arizona Center for Algae Technology and Innovation, or AzCATI, on Arizona State University’s Polytechnic campus is laying groundwork for algae-based technologies and systems to provide cleaner fuels, efficient wastewater treatment, environmental restoration and renewable chemical feedstocks. The center is part of ASU’s Ira A. Fulton Schools of Engineering. Photo courtesy of AzCATI

Joe Kullman

Science writer , Ira A. Fulton Schools of Engineering


image title

The Wizard of Ooze

Algae as fuel, fertilizer and food — for animals AND us? ASU prof thinks so.
It's not easy being green — but algae could be a major player in sustainability.
May 11, 2016

Polytechnic prof Milton Sommerfeld exploring the possibilities of algae as super food, fuel, fertilizer and more

Milton Sommerfeld can see the future in puddles.

One of the nation’s top experts on algae, Sommerfeld has spent almost 50 years cracking dozens of uses for the plant. In Sommerfeld’s future, you will fill your tank with it; feed it to livestock; fertilize crops, lawns or flowers; clean up wastewater with it; and eat it.

One of the best strains he ever found was in a puddle after a storm in Phoenix.

“We picked it up and it started growing, and it produced over 50 percent of its weight as oil,” Sommerfeld said. “You never know where you’re going to find an algae strain that has value for a different type of product.”

There are about 75,000 different types of algae, ranging from microscopic specimens to kelp a hundred feet long and as big around as a baseball bat. It can look like lime Kool-Aid, black or brown crude oil, or hearty burgundy.

“It’s a very broad-spectrum use,” said Sommerfeld, professorSommerfeld is a professor in the Environmental and Resource Management Program in the Polytechnic School, which is part of the Ira A. Fulton Schools of Engineering. Sommerfeld is also a senior sustainability scientist in the Julie Ann Wrigley Global Institute of Sustainability. in the Polytechnic School and co-director of the Arizona Center for Algae Technology and Innovation.

“The focus has been on biofuels,” he said. “It’s believed that the petroleum we take out of the ground had its origin in algae millions of years ago. If you look at the chemistry of algae oil, the lipids, it pretty much matches petroleum. Anything you can use petroleum for, you can pretty much use algae oil. That means not only fuel in terms of diesel, gasoline and jet fuel — you also have the specialty products that can be made, like plastics and so on.”

ASU algae expert Milton Sommerfeld

ASU professor Milton Sommerfeld is co-director of the Arizona Center for Algae Technology and Innovation. He has studied algae for 48 years and says there is much yet to be discovered. Photo by Ken Fagan/ASU Now

Algae has some surprises in its membranes, like Omega-3 fatty acids, which are believed to help cardiovascular health, among other benefits. Omega-3 is usually referred to as a fish oil. It’s actually an algae oil. Algae oils will eventually replace Omega-3 supplements found in health-food stores.

“The fish have simply accumulated them by eating little animals that ate algae,” Sommerfeld said. “We always say, ‘Let’s cut out the middle fish and go right to the algae for those specialty products.’ ... We just haven’t used the algae to its fullest extent. More and more people are looking at the algae as the source for some of these specialty products that actually now comes from a plant source.”

Sommerfeld grew up on a farm in Texas. His father made him clean the algae out of the cattle trough. Every week, he cleaned it out. Every week, it came back.

“I kept wondering why it grew so fast,” he said. “That was how I first related to the algae.”

One of the major focus areas of Sommerfeld’s lab is how to relate algae to the water-energy-feed nexus. Algae can be grown in dairy wastewater or in sludge from water treatment plants, stuff that’s usually trucked to landfills. Grow algae in that, take out the oil, and you’re left with a nitrogen-rich biomass perfect for fertilizer.

“It’s high-protein,” Sommerfeld said. “Now you have a high-protein source for animal feed, or even potentially human food.”

The biggest immediate impact from algae will be bioremediation — cleaning up environmental threats — and producing specialty chemicals, according to Sommerfeld.  Why not fuel, if it’s so readily extracted? Sommerfeld has cooked up biodiesel in his lab from algae. Why hasn’t ExxonMobil built giant ponds?

The problem is taking algae farming to a large scale. Most work with algae has been at small scale, although some people have tried unsuccessfully. There are huge challenges in introducing a new crop to industrialized agriculture. 

“Just think about trying to introduce a new crop at large scale,” Sommerfeld said. “We don’t do that now.

“If you look at our crop plants, they started on small farms and got bigger and we learned how to do it and got bigger machinery and bigger this and bigger that, all kinds of improvements in seed because through a different process because there was a big market for food or whatever you get out of the grain.

“Now you’re trying to do this with a product that’s a commodity product: oil. It’s a commodity product. It’s cheap. Now you’re trying to compete with an industry that’s been here more than 100 years.”

On a four-acre site directly across the street from Sommerfeld’s lab on ASU’s Polytechnic campus in Mesa, he is working on bringing algae cultivation to a production scale. In the baking sun sit racks of panels with algae bubbling in them and long test beds lined with white plastic where mill paddles churn scarab-green and wine-dark water. Four years ago the U.S. Department of Energy invested $15 million to find out how to grow algae outdoors in a production setting.

There’s a lot more to it than simply transferring what you did inside in a test tube to a 300,000-liter test bed outside. Sometimes that works, Sommerfeld said. Sometimes it doesn’t.

“One of the things that happens we’re finding when we started to begin to scale up and do it outdoors, it’s that there are a lot of little animals that get in,” he said. “We have the same kinds of problems that farmers have with insects.

“Now you have these creatures that blow in with the wind and the dust storms, and they love to eat the algae. They cause what we call algal crash. All of a sudden the cells begin to come together and turn brown and settle down. It’s sort of like they’re dead, and you have to almost restart the system, which is very expensive on a large scale. One of the things we’ve been doing recently is really trying to detect and identify those organisms and look at how do we control them like insects. We’re having a little success in doing that.”

ASU algae expert Milton Sommerfeld and a colleague.

Dr. Emil Puruhito (left) and Dr. Milton
Sommerfeld stand by one of the algae
research ponds at the Arizona Center
for Algae Technology and Innovation
at the Polytechnic campus.

Photo by Ken Fagan/ASU Now

Controlling crashes can be done physically or chemically. Sommerfeld’s lab works on both, but leans towards chemical solutions.

“The treatment for different organisms is different,” he said. “We’re trying to sort that out. ... It’s like anything else. If a farmer detects boll weevils, he sprays and then inspects again. ... You look for resistant species. Then you look at it, OK, this is one we really want to grow. Now how do we keep it in a viable way?”

Despite a lifelong fascination with the plant and 48 years studying every facet of it, much remains to be learned.

“One of the great things about science is every time you think you know something, you really do, but there’s another question out there that leads to something interesting,” Sommerfeld said. “You’re never at the end point.”

Top photo by Charlie Leight/ASU Now

ASU In the News

ASU develops algae fuel source at Polytechnic campus

Writer Mike Sakal from the East Valley Tribune asks in a recent article: "Can Arizona State University's Polytechnic campus be a world leader in developing an alternate fuel source for transportation?"

"Directors of its Arizona Center for Algae Technology and Innovation (AzCati) lab believe that it can," writes Sakal. "Right now, it's simply being called Arizona Crude." Download Full Image

Sakal reports on ASU's recent dedication of the Polytechnic campus' expanded AzCati center. He talks with leading algae researcher Milt Sommerfeld, who is co-director of the AzCati lab, and Tom Dempster, manager for the AzCati lab.

"Although making fuel from algae is not a new concept for alternative fuel sources, as it was first conceived during the Middle East's oil embargo on the United States in the late 1970s, AzCati plans to cement future partners into its ecosystem to advance the project," Sakal writes. "It currently has about 50 worldwide partners in the research and development project as well as numerous local organizations."

Access entire article below.

Article Source: East Valley Tribune