Photo By Brigida Sanchez | Harmful algal blooms are a challenging problem that has impacted human and animal...... read more read more
But looking at it through an engineer’s eye I could see perfect conditions for them to slowly multiply and take over the freshwater expanse of the lake, and slowly suffocate the native ecosystem.
I am spending the morning with the Opera- tional Water Research Team of the U.S. Army Engineer Research and Development Center (ERDC), Construction Engineering Research Laboratory (CERL) in Champaign, Illinois, searching for algal blooms that were swept away in Lake Okeechobee by wind and current.
Our boat stops in what seems to be the center of the lake to gather samples of the drifting Harmful Algal Blooms (HABs). Members of the team are wearing N-95 masks and latex gloves, and carrying a massive case of equipment to collect water samples from various locations on the 730 square miles of water.
The HABs team needs as many specimens as possible to identify the type of bloom and determine a way to intercept, treat and transform the algae as a part of a research demonstration study.
The blooms found on the lake sometimes produce toxins, but they can also have other impacts. Harmful algal blooms are essentially overgrowths of naturally occurring algae, part of the natural cycle of nutrient transport in the environment. When excessive nutrients become coupled with environmental conditions that favor algae growth, algal blooms become the primary driver of water body degradation, a process called eutrophication that decreases oxygen levels and generates foul odors.
Nutrient pollution and harmful algal blooms cost the nation an estimated $1 billion yearly.
The Florida Department of Health estimates the economic impact of HABs at $22 million annually, including medical expenses and lost wages.(1)
In 2019 alone, Florida allocated $17.3 million of its $19 million research and response budget to dealing with HABs. According to the Florida Department of Environmental Protection’s Algal Bloom Sampling Status Dashboard, within the past 30 days there have been 114 observations of various types of HABs in Florida.(2)
Considering the widespread nature of the HAB threat, Martin Page PhD, Operational Water Research Team lead at the U.S. Army Engineer Research and Development Center (ERDC), Construction Engineering Research Laboratory (CERL) in Champaign, Illinois said, “Cyanobacteria and harmful algal blooms are one of the greatest environmental challenges that our country is facing. They are occurring across the nation, and these algal blooms impact many areas. They have both environmental and economic impacts on the communities where they are happening.”
And that’s what brought Page and his team to Lake Okeechobee, to set up the 2020 demon- stration of the Harmful Algal Bloom Intercep- tion, Treatment and Transformation System, known as HABITATS. They are testing the new HAB mitigation process through which the harmful blooms are intercepted, treated and transformed into benign and useful products such as biofuel. This year the team was experimenting to improve fuel yields by incorporating various environmentally friendly organic chemicals in the treatment process, and increasing the system’s scalability and ease of deployment.
Page said the team had to consider and pre- pare for a wide range of factors when planning the demonstration study. Weather always plays role in the field, so they were prepared for every- thing, or so they thought, including hurricanes, but what they could never have anticipated was a global pandemic.
COVID-19 was just one of the challenges that the team, mostly traveling to Florida from out of state, would have to overcome in their 2020 study. Nonetheless, they persisted. They adapt- ed the study to accommodate travel restrictions for some members and succeeded in mobilizing most of the team to the Port Mayaca spillway on Lake Okeechobee in July, which is when blooms tend to be present.
But strong windy conditions had dispersed the algae from the lake’s permitted test site, making demonstration testing infeasible. So the resilient HABITATS team moved quickly, re-mobilized and, working closely with the Corps’ Jacksonville District and its Florida state partners, found an alternate location to set up and pilot the demonstration.
The team moved and re-established the HABITATS at Saddle Creek in Polk County. Their flexibility and ability to shift quickly to a site some three hours down the road led them to success.
“Algae is a moving target,” said Page. “It is a challenge because a lot of planning goes into these projects, and the technology is always advancing, so we are constantly learning and adjusting. We worked very closely with the Florida Department of Environmental Protection to make sure we could conduct our work safely.”
Driving north from the lake to Saddle Creek, I could see how HABs had overgrown some small lakes adjacent to housing developments. I stopped to capture photos and this time there was nothing remotely mystical to what I wit- nessed. My camera and I confronted a toxic, stagnant, green blanket of growth covering the small body of water. I was left feeling over whelmed, standing there camera in hand, painfully aware of the urgency of the team finding a solution to the problem spread out before me.
There are three elements to the HABITATS approach: interception, treatment and transfor- mation. Interception focuses on getting as many algal blooms out of the water efficiently, using as little energy as possible. Treatment consists of pushing the water through treatment systems at high processing rates, again conserving as much energy as possible. The algae and the water are separated into a concentrated, almost paste-like form.
In this condition, the concentrated algal blooms constitute biomass waste that is potentially toxic, depending on the algae it contains. This is the substance the team is working to convert into a safe and sustainable product, which bring us to the third element of HABITATS - transformation.
This year the team is investigating hydrothermal liquefaction on a pilot scale, said Page. They are attempting to concentrate thousands of gallons of the harvested algae slurry paste into a bio- crude fuel through the hydrothermal liquefac- tion process. Once optimized, the process can be net energy positive, and the bio-crude can be upgraded for various uses.
“This work is very challenging, and it is a dy- namic system,” said Page. “We don’t have control all the time about what the environment is going to do. It presents problems in terms of project execution, but technically we are focused on putting the puzzle pieces of the HABITATS process together and optimizing our efficacy.”
The HABITATS team does not work alone, Page pointed out. It is one element of a collective force of scientists, engineers, outreach coordi- nators, government and not-for-profit agencies, contractors and businesses of many sizes. In much the same way as tiny algae particles can dance and grow into a large scale threat to the environment, the HABITATS collaborators are a collective of synchronized strength developing its own dance to clean polluted water and create a safer, healthier biosphere that sustains ecosystems and allows societies to enjoy the beauty of the natural world.
The U.S. Army Corps of Engineers Operation Research team’s priority is to clean the water and discharge it back into the environment. The pro- cess is challenging, but the urgent need to find an ecologically sustainable solution propels the team forward to find solutions for our nation’s water systems.
References:
1. Florida Department of Health, Harmful Algal Blooms-Economic Impacts . http://www.florida- health.gov/environmental-health/aquatic-tox- ins/_documents/economic-impacts.pdf
2. Florida Department of Environmental Protec- tion’s, Algal Bloom Sampling Status Dashboard. https://floridadep.gov/AlgalBloom
| Date Taken: | 07.25.2020 |
| Date Posted: | 12.31.2020 17:24 |
| Story ID: | 386315 |
| Location: | OKEECHOBEE, FL, US |
| Hometown: | BARTOW, FL, US |
| Hometown: | JACKSONVILLE, FL, US |
| Hometown: | PALM BEACH, FL, US |
| Web Views: | 77 |
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This work, The Synchronized Dance of Sustaining our Ecosystems, by Brigida Sanchez, identified by DVIDS, must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
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