In early July, parts of Florida were dealing with massive algal blooms, which closed many beaches in southern regions through the Fourth of July and continue to pose a threat to aquatic life in the area. For residents, algal blooms do pose some health concerns, not to mention the putrid smells caused by the dying algae contained in these blooms. On June 29th, Florida Governor Rick Scott declared a state of emergency in the counties of Martin and St. Lucie because of algal blooms. The next day, Lee and Palm Beach counties were also added to the state of emergency order. The blooms were caused by water discharges from Lake Okeechobee released by the U.S. Army Corps of Engineers to relieve flooding risks from that lake which, according to reports, has taken in enough water this year to cover the state of Delaware.
Algal blooms are caused when algae living in seas or freshwater grow uncontrollably because of the presence of nutrients like phosphorus or nitrogen; high temperatures and the underwater penetration of light also play roles in the process. Various species of phytoplankton can cause blooms, although a typical bloom doesn’t contain many species, and at their highest concentrations they can reach hundreds of thousands of cells per milliliter of water. Fish and other marine life, including plants, can die from lack of oxygen and nutrients. Algae can also release toxins into the air, causing respiratory ailments. A study published in 2009 by Environmental Health Perspectives pegged the costs of treating respiratory problems caused by blooms up to $4 million.
Public health costs, however, are dwarfed by the price tag which algal blooms can put on industries requiring clean water, such as seafood, tourism and restaurants. Every year, harmful algal blooms (HABs), the toxic variety currently seen in Florida, cost about $82 million in lost economic output according to statistics published by the National Oceanic and Atmospheric Administration (NOAA). Last year, algal blooms on the West Coast caused beaches in Washington State to close, preventing razor clamming at an estimated economic cost of $9 million over one month.
One technique currently being explored to combat the spread of algal blooms is removing the nutrients which allow those blooms to thrive. Algae control programs often focus on nutrient reduction but those long-term management plans only show results after many years. One water treatment offering a short-term solution is known as Phoslock, a chemical composition including lanthanum which can bind to free reactive phosphorus in bodies of water and then drag it to the bottom. This algal bloom treatment was developed at the Australian science agency Commonwealth Scientific and Industrial Research Organisation (CSIRO). Phoslock Water Solutions, the company that now markets the phosphorus removal technology, does have U.S. intellectual property protecting the treatment. U.S. Patent No. 6350383, titled Remediation Material and Remediation Process for Sediments, was issued in February 2002. It protects a method for remediating matter selected from sediments and effluents by removing phosphorus and oxyanion pollutants with the use of an aluminosilicate clay.
Phosphorus removal is also a focus at the Florida-based Green Technologies, a firm involved in researching and developing systems for recycling nutrients from wastewater. Last September, the company was chosen as a recipient of a Small Business Innovation Research (SBIR) grant made available through the U.S. Environmental Protection Agency (EPA). The technology, developed at the University of Florida and optioned by Green Technologies, can treat stormwater or runoff on the order of tens of thousands of gallons per day for phosphorus removal. The $100,000 in Phase I funding will help Green Technologies commercialize its phosphorus removal and recycling innovation.
Although it’s unclear whether this is the patent optioned by Green Technologies, we did find a University of Florida patent related to phosphorus filtration systems. U.S. Patent No. 8002984, entitled Green Sorption Material Mixes for Water Treatment, issued in August 2011 and claims a sorption media comprised of recycled material such as tire crumb or wood sawdust as well as a naturally occurring media like sand, limestone or peat. The stormwater and wastewater treatment can control nitrogen and alkalinity levels along with phosphorus.
Water picks up many of the chemical nutrients that fuel algal blooms when it travels through soil as groundwater. A septic system biofilter developed by researchers at the Center for Clean Water Technology at Stony Brook University could reduce nitrogen released into the ground by up to 95 percent. The nitrogen removing biofilter is composed of a mixture of sand and wood pulp and septic waste and achieved nitrogen removal rates of 85 percent to 95 percent in early tests. Installation costs on a residential property were reported to be $10,000.
Algal blooms can soak up great amounts of dissolved oxygen in the water, causing the destruction of much marine life in its wake. BlueInGreen of Fayetteville, AR, is a developer of gas delivery systems for water management and maintaining water quality. In late June, the company completed its 25th installation of systems capable of delivering up to 7,800 pounds of dissolved oxygen per day, or treating up to 5 million gallons of water per day. The company was also preparing for its first international installation of a gas delivery system in Alberta, Canada, by the end of this summer.
BlueInGreen holds one U.S. patent which it received this April, U.S. Patent No. 9315402, which is titled Systems and Methods for Wastewater Treatment. It protects a system for treating wastewater including a bioreactor receiving untreated wastewater, a membrane module, a gas source and a dissolution tank for dissolving oxygen into the untreated wastewater. This technology overcomes limitations in conventional membrane bioreactor (MBR) systems in which oxygen dissolution becomes impractical when the concentration of solids in wastewater is greater than three percent.
Over in Europe, the European Union-sponsored DRONIC Project seeks to develop autonomous vehicular systems for the removal of algal blooms. The robotics project, scheduled to last 30 months, will encompass the creation of two unmanned surface vehicles (USVs), one that will assess water quality and map algal blooms and another which will treat algal blooms using ultrasound waves. Ultrasonic technologies have been employed in the past to control either blue-green or green algae as ultrasound waves can destroy algae on a cellular level without affecting other marine life, including people. LG Sound, a Netherlands-based company involved in the DRONIC Project has created ultrasonic water treatment systems in the past which could treat water within a diameter of 500 meters (1,640 feet).
Reports from last November from multiple media outlets discussed a similar algae removal concept designed by a Swedish student which relies on the use of drones. The concept is designed specifically to treat algal blooms forming in the Baltic Sea and also relies on drones serving in two different roles. One drone would vacuum up algae and then transfer it to a second drone which dries the algae and turns it into drone fuel to dispose of the collected algae. In a follow-up piece, we’ll also look at how algae from algal blooms can be repurposed as biofuels and other kinds of consumer products.