Study of alfalfa phytofiltration technology to clean heavy metal contaminated waters

Kirk Jon Tiemann, University of Texas at El Paso

Abstract

Heavy metal contamination of the environment has become a serious concern. Traditional methods which are currently used are costly and may prove prohibitive for some contaminated sites. Therefore, there is a need for the development of a cost effective remediation system for the removal and recovery of these contaminants. If a remediation system can be made that is profitable, more industries will clean their effluents and protect the environment and remediation of current sites could be achieved. The main objective of this project is to determine the ability of alfalfa biomass to bind different heavy metal ions under a variety of harsh conditions in order to develop an innovative filtration system using alfalfa for the economical removal of toxic heavy metal ions from contaminated waters in a recyclable form for industrial reuse.^ Results of these studies have shown that alfalfa is not only effective at removing contaminants from waters, but also possesses the unique ability to allow for recovery of these contaminants in a usable form for industrial recycling. In addition, we have determined that high levels of calcium and magnesium which typically foul conventional commercial systems are do not greatly hinder the binding of some of the metal ions studied. Previously performed column experiments have proven that silica immobilized alfalfa has the capacity to be reused over twenty applications and still remain efficient and practical for the removal and recovery of copper ions from water. These results show that alfalfa is effective for removal of copper, cadmium, chromium, nickel, lead, and zinc from aqueous solutions. Even with mixed-metal containing solutions, the alfalfa phytofiltration system has shown remarkable metal recovery. Also, studies were performed to determine the heavy metal binding mechanism through chemical modification and X-ray absorption spectroscopy. Since silica-immobilized alfalfa is biodegradable it will not harm the environment. In addition, the alfalfa biomass has a unique ability to reduce gold(III) to gold(0) through a different binding mechanisms which could allow for the separation of gold ions from other heavy metals. These studies will be important in creating an economical system to clean heavy metals from contaminated waters and industrial effluents. ^

Subject Area

Chemistry, Biochemistry|Environmental Sciences|Engineering, Environmental

Recommended Citation

Tiemann, Kirk Jon, "Study of alfalfa phytofiltration technology to clean heavy metal contaminated waters" (1998). ETD Collection for University of Texas, El Paso. AAI9832816.
http://digitalcommons.utep.edu/dissertations/AAI9832816

Share

COinS