Tag: algae

The Threat of Toxic Algae and Aquatic Dead Zones

The Swamp Stomp

Volume 14, Issue 43

The last few decades have seen an increase in efforts to better understand the toxic algae and oxygen-hungry aquatic dead zones that have been appearing around the world. These threats are currently two of the largest dangers facing the world’s oceans and fresh water reserves. Little benefit has emerged from increased research, however. In fact, recent evidence suggests that such algae and dead zone hotspots are growing in size, and pose greater threats to fisheries and consumable drinking water.

Studies published in Science, a respected scientific journal, suggest that both phenomena are effects of the increased amounts of fertilizer, manure, and wastewater running into lakes, rivers, and oceans. Such studies have received backing from the U.S. National Science Foundation and other similar institutions.

August 2014 saw the drinking water plant in Toledo, Ohio, one of the largest cities located on the Great Lakes, close due to a toxic bloom. This was the first time that a large American city has faced such an incident. However, since 2004 toxic algae infestations have shut down water supplies to more than 3 million people over 3 continents. Outbreaks to Australia’s Murray River, China’s Lake Taihu, and Kenya’s Lake Victoria are only a few instances of the problem escalating on a global scale.

When algae blooms die, the areas that they once consumed become dead zones. These low-oxygen areas decompose, causing the fish and other wildlife native to the habitat to either flee or die as a result of the new water conditions. Similar to toxic algae outbreaks, the amount of dead zones are increasing. A 2008 study by the Virginia Institute of Marine Science discovered over 400 dead zones that together cover 245,000 square kilometers worldwide.

If these obstacles are not addressed, then the events that occurred in 2007 to China will act as warning to what the world can expect in the future. A significant algae bloom affected Lake Taihu—a 2,250-square-kilometer lake that supplies water to over 10 million people for consumption, as well as for industrial and agricultural purposes—and left 2 million people without water. It took a month to clean the lake and restore full drinking water service. The inhabitants of the nearby city of Wuxi were forced to only drink from bottled water for the duration of the cleansing period.

Hans Paerl, a professor at the University of North Carolina-Chapel Hill who worked to curb the algae in Lake Taihu, claimed, “We are using Lake Taihu as a looking glass for how bad things could get here [in the U.S.].” He said that “back in the 90’s, the lake had gone through a state change where the blooms initially started appearing but were not too serious.” However, he continued, “Within a matter of 5 to 10 years, the lake shifted to a situation where blooms started to pop up in the spring and persist through the summer. The change is very extreme. Now, blooms start in early May and run all the way into November—more than half the year.”

Paerl concluded that in order to remedy the problem in China, the amounts of phosphorus and nitrogen running into the Lake Taihu must be reduced by 50 percent. Considering the incident at Lake Taihu is viewed as a warning of what may happen to the United States in the future, it is reasonable to expect that similar proposals may be made in the not so distant future as prevention measures.

These phenomena do more than only cause environmental trouble, however—they also prove to be large economic obstacles. The increase in toxic algae blooms and aquatic dead zones cause a loss in seafood sales, higher drinking water costs, losses to livestock, and lower tourism revenues. The National Oceanic and Atmospheric Administration estimates that the U.S. loses 82 million dollars annually due to toxic algae and dead zones on coastal waters—a much lower number than those of Australia and the European coastal countries.

The combination of environmental and economic qualities makes the handling of toxic algae and aquatic dead zones a possible major talking point in upcoming political conversations.

Fuel Benefits of Algae

Swamp Stomp

Volume 14, Issue 37

For years Algae has been used as fertilizers, soil conditioners, and as a source of nutrition for animals. Derived from the first declension Latin word ‘alga’, algae literally means ‘seaweed’, and has generally not been used as much more than that. It captures runoff nutrients from soil deposits, and in turn becomes harvested as a fertilizer itself.

Algae also contains other useful molecules, such as lipids, and thereby has the potential to be used in order to make a number of profitable items, including high-energy fuel. However, the ability to extract these molecules is an arduous and expensive task, and, therefore, has yielded little reward. Until now, that is.

Algae Systems, a company based in Nevada, owns a pilot plant in Alabama that is used to generate behavioral information on algae. It is a smaller facility that is intended to identify a specific focus for algae study before larger plants are devoted to the cause. Subsequently, it claims to have found a way to produce diesel fuel from algae.

The process works by performing three separate tasks. First, municipal sewage, a treatment used to fertilize algae, must yield clean water. Second, a carbon-heavy residue must be used as fertilizer for the algae. Finally, valuable credits for advanced biofuels must be generated. If these tasks are completed in conjuncture with one another, then Algae Systems claims that a greater level of carbon will be extracted from the atmosphere then is added during the consumption of fuel.

The system works by heating the algae, along with the other solids found in the sewage, to temperatures in excess of 550 degrees Fahrenheit, at 3,000 pounds per square inch. This produces a liquid that appears similar to crude oil from a well. The chief executive of Algae Systems, Matt Atwood, refers to this as a “hydrothermal liquefaction” system.

Once produced, the liquid was studied by scientists at Auburn University, who, acting in line with the common procedure for oil refinement, added hydrogen to the liquid. This, subsequently, produced diesel fuel, which was later confirmed by Intertek, an independent laboratory, to meet all of the industries specifications.

The intriguing aspect of Algae Systems’ process is the means by which they separate the individual molecules from the algae. The high level thermal process they implement is a new system in algae treatment. It produces the potential to greatly reduce the amount of energy exerted on extracting molecules from algae.

Halil Berberoglu, an assistant professor of mechanical engineering at the University of Texas at Austin, is also researching this area of algae treatment—separate from Algae Systems—and is excited by the prospect of such a “hydrothermal liquefaction” system. He described the older system as being “very energy-intensive,” whereby one must “dewater the algae, poke holes in the cell walls, and do all kinds of separation technologies.”

The high thermal process would not only allow the separation of lipids from the algae, but also the separation of proteins and carbohydrates, which may lead to further uses of algae.

Many obstacles remain in the advancement of such a process, for example the possible incorporation of heavy metals, nitrogen, and sulfur in crude oil compounds. Nonetheless, Algae System’s new perspective on algae treatment is both promising and refreshing.