Aeration Solutions

working to solve the adverse effects of algae blooms and have developed a prototype aeration system that will help limit algae growth.  Check out our aeration prototype.

 

 

EAS Solutions for Reducing Algae

Algae blooms prove to be a nuisance in Ohio water bodies during the warmer months. The blooms exhibit adverse effects on the aquatic environment and can be visually unappealing and foul-smelling.  In addition, algae blooms (cyanobacteria) create a toxin called microcystin which causes nausea, diarrhea, vomiting, headaches and liver damages if ingested by humans. 

 

Environmental Analysis and Solutions (EAS), LLC has developed two solar-powered prototype aeration systems. These systems will help keep a pond from going anoxic and prevent phosphorus from being released back into the water column for use as a nutrient.  The systems provide oxygen to the water preventing the phosphorus from being re-released into the water column.

The Problem

Algae blooms prove to be a nuisance in Ohio water bodies during the warmer months of the spring, summer, and fall seasons. The blooms exhibit adverse effects on the aquatic environment and can be visually unappealing and foul-smelling in some cases.  In addition, some algae blooms (cyanobacteria) create a toxin called microcystin which causes nausea, diarrhea, vomiting, headaches and liver damages if ingested by humans. 


The presence of cyanobacteria in Ohio lakes results in posted warning notices limiting contact with water. In August 2014, the city of Toledo shutdown their drinking water supply system since their water source (Lake Erie) was contaminated with cyanobacteria.  In September 2015, a swim across the Ohio River near Cincinnati was cancelled due to the presence of algae in the River.  Algae blooms in Ohio water bodies are a recurring issue each year in spite of attempts to resolve the problem.

Background

Algae blooms typically occur during the spring and summer months when nitrogen (N) and phosphorus (P) from fertilized fields, some sewage treatment plants, and septic systems wash into a body of water during rainfall events.  The N and P provide nutrients for algae to reproduce and bloom.  Over the last five years, a number of different methods have been used to address the algae problems in some Ohio water bodies.


The state of Ohio’s effort focuses on reducing the source of N and P from entering water bodies by controlling run-off during precipitation events.  Millions of dollars have been spent over the last five years to control run-off of fertilizers from farmers’ fields and using algae treatment methods.  The control of run-off is certainly an effective and necessary method to limit N and P from entering a watershed system. Unfortunately, the implementation of the run-off controls may take up to several decades before results of limiting algae blooms are seen due to the amount of fertilizers used for the last 50 years in Ohio.  


The state of Ohio has also used chemical treatments, bottom sediment dredging, isolated aeration, and trash fish harvesting as methods to combat algae blooms on Grand Lake St. Mary’s (the largest man-made lake in Ohio).  All of these methods proved successful in reducing algae blooms on a limited basis at combined costs of millions of dollars.  However, these methods were used at various times over the last several years and blooms continue to occur because of the size of the lake and the total amounts of N and P present in the lake.

Aeration from EAS

Although both N and P are the main nutrients used by algae, our study focused on P since that chemical can be retained by the bottom sediment of the water body whereas N (usually in the form of ammonium and nitrate) is not.  Unless the water body bottom is dredged to remove the P entrained with the sediment or treated chemically to bind P, P is re-released every year once the lake goes anoxic [no dissolved oxygen (DO) content].  Algae contribute to low DO conditions when die-off occurs in the fall/winter.  Algae decompose during the fall/winter (using oxygen in the process) and become deposited in the sediment bottoms of the lake. The growth and die-off cycles begin again the next year.


Environmental Analysis and Solutions (EAS), LLC developed two prototype solar-powered  mixing/aeration systems that will help  keep small  ponds  from going anoxic.  The systems provide oxygen to the water body and prevent P from being released back into the water column for use as a nutrient again.  By preventing the re-release of P back into the water column, the algae growth is limited. 


Prototype Systems

Environmental Analysis and Solutions, LLC developed two prototype solar powered mixing/aeration and agitation systems to combat algae formation in small ponds.   The systems were developed to mix/aerate surface water (contains high dissolved oxygen content) with the deeper lower dissolved oxygen content water residing on the pond bottom.  The systems float on the water surface and use a motor for both agitation and propulsion.


The first system developed and tested from May 2018 through September 2018 operated successfully on a 0.4 acre pond in Indiana.  The depth of the pond was about 18 feet. The system consisted of a “pond hopper” boat, batteries, controllers, timers, pump, and a motor.  All the equipment was “off-the-shelf.” The boat was tethered in the middle of the pond but is able to drift in radial distances around the tether line. Two solar panels recharged the system’s batteries,  keeping the pump and motor operating for approximately 8 hours per day.   After 6 weeks of successful testing, the batteries, controllers and timers were removed from the boat to see if the equipment could function solely on solar power.  The next testing period used only power from the solar panels wired directly to the pump and motor.  That testing period lasted until the end of September. A second prototype system consisting of a “floating dock” platform  was launched the last week of September. The dock platform remained in the pond for 3 weeks of testing.  That unit used the same solar panels, pump, and motor that were used with the boat.


Both systems functioned well and provided valuable information on how solar power can be used to combat algae formation in small ponds.  (Note:  Somewhat ironic considering how sunlight powers the photosynthesis process which is needed to drive algae growth).  Both aeration systems offer a natural alternative at competitive costs to chemical treatments and an AC powered aeration system.  Since the  components functioned without any maintenance over the 5-month test period, the same systems will be deployed in 2019 with no additional capital expenses.  Testing is planned in 2019 for ponds or canal areas that have experienced more severe algae growth to determine effectiveness.  So if you have an algae problem and would like EAS to deploy a prototype unit for use (no charge since we’re still testing) in your pond or canal, just contact me at the phone number or email address listed below.