Phytoremediation: The solution for arsenic contamination

. More recently scientists have discovered an application to clean up a hugely controversial contaminant: arsenic. This discovery may give phytoremediation the publicity it needs to move forward as an effective and reliable technology in the United States.

By Sanya Sahi, Research Analyst, Environmental Health and Safety, United States

Although phytoremediation has been around since the beginning of time, only recently have scientists, engineers and business people come together to fine tune this relatively simple concept: that plants can actually clean-up toxic pollutants in soil and groundwater naturally. Interest in commercial phytoremediation only truly began in the early 1990s. A significant turning point for this technology was its use to decontaminate soil and groundwater at Chernobyl, Ukraine in 1986. After phytoremediation proved successful in this instance the market for these toxin-eating plants began to grow as new applications were discovered. More recently scientists have discovered an application to clean up a hugely controversial contaminant: arsenic. This discovery may give phytoremediation the publicity it needs to move forward as an effective and reliable technology in the United States.

With the large amount of controversy pertaining to the arsenic rule put out by the EPA, and the recent reconsideration of this rule by the Bush administration, this issue has been making headlines across the US. A large part of this controversy is due to the costly cleanup needed to meet the standards determined by the EPA. Many of the communities that the standard is directed at are small in population with less than 3,300 people, with very limited financial ability to afford compliance or lobby against the rule. In order for the many small communities to meet the standards they would be forced into very expensive treatment.

A possible solution to this issue may be the consideration of phytoremediation. Phytoremediation may be the perfect solution to the controversial arsenic dilemma. For years the site remediation industry has been searching for a cost-effective, ethical method to clean up contaminated sites, and now they may have found it. Researchers from the University of Florida discovered that a common brake fern, or Pteris vittata, is the first plant found to hyperaccumulate arsenic. This plant has proven highly efficient in soaking up arsenic, showing levels as much as 200 times higher in the fern than the concentrations in the soil where it is growing. Recognizing that these ferns may potentially present a huge market for the cleanup of arsenic all around the world scientists are now fine tuning their research to concentrate on how the plant takes up, distributes and detoxifies the arsenic. The Pteris vittata is likely to be a large player in the phytoremediation industry due to its ability to accumulate such high concentrations of the toxin. Other phytoremediation plants have not proven as successful as this one.

Although the process of phytoremediation sounds simple, there is a bit more preparation involved than simply planting trees around a toxic waste site and letting them do their thing. Rather, a significant amount of preparation and research is involved before an engineer can actually determine which plants to use and how the plants break down the contaminants that are being targeted. For instance, there are occasions where plants may break down a product and produce even more hazardous bi-products. With this in mind, the implementation and effectiveness of phytoremediation processes is only as good as the research and preparation done before hand. The emphasis on understanding the basics of contaminant break down are crucial for developing phytoremediation solutions. Other concerns when determining which plant to use might be the climate or environment in which the contaminant is being treated. For example, some plants that might flourish in Florida may not grow at all in the colder less humid climates. Additionally the depth or location of the contaminant must be considered.

According to D. Glass Associates, the overall phytoremediation market will reach revenues between $214 million to $370 million by 2005. With this proven ability to clean up arsenic, it is now more likely than ever before that the phytoremediation market will become a more important part of the overall remediation market, thus revenues for this market may be higher than originally thought. It is likely that companies already involved in natural clean up technologies will want to develop a phytoremediation component to add to their line. Phytoremediation companies are smaller regional manufacturers that will realistically have to partner with larger engineering firms to work on contaminated sites. This is mainly due to the fact that there are very few sites that can be cleaned up solely by phytoremediation. Rather, like most cleanup technologies, they have to be coupled with others in order to be totally effective.

Therefore, small phytoremediation technology developers will likely lack the necessary resources to be successful on their own in the site cleanup industry. By partnering with large engineering firms or licensing out their technology they will penetrate the market more easily. These companies will likely aid phytoremediation to become more widely accepted within the remediation community. As developers and end-users become more familiar with the advantages of phytoremediation, begin to understand the possibility of new applications, and discover technologies that help meet regulatory standards- this market is set to see positive growth.

Whether or not the arsenic standard is ultimately passed in the United States there will still be a significant market for the Pteris vittata all around the world. Arsenic has become a problem in many parts of the world as a result of leaching from mine tailings and being used as a pesticide in the US, Canada, Mexico, Thailand and Japan. Recently Bangladesh was determined to be one of the most highly contaminated countries in the world. The United Nations states that around 25 million Bangladeshis are at risk of disability or death from arsenic poisoning from the country's drinking water. The World Health Organization claims that the level of arsenic poisoning in Bangladesh is one of the largest ever. With this massive worldwide market for the cleanup of arsenic the Pteris vittata plant is likely to drive the phytoremediation market towards a long and healthy future.

(c) 2001 Frost & Sullivan, All Rights Reserved.

More in Technologies