Use of Silica-Supported Adsorbents, Modified Silica Gel, Modified Montmorillonite KSF and Magnetite in the Remediation of Selected Heavy Metals from Aqueous Media

Pollution of the earth\u27s water resources, including freshwater sources such as lakes and rivers, by heavy metals have been a detriment to the environment for as long as the industrial age of man. As these metallic pollutants accumulate in the supply of precious groundwater and drinking water the need for clean-up technologies to combat the increasing threat is becoming of more importance to government and industry alike. Previous work has established the possibility of using known chelating agents, such as LIX-54® supported on silica gel in the removal of selected heavy metal ions such as copper(II), nickel(II) , and cadmium(II) from standard aqueous solutions (Norris and coworkers, 1996). Remediation of heavy metals using coordinating agents such as dithiooxamides and aliphatic amines has also been an environmental cleanup technology that has proven to be effective in the uptake of selected heavy metals from aqueous media (Poore and coworkers, 1996). The current study illustrates the effectiveness of using relatively inexpensive coordinating agents such as aliphatic amines and aliphatic thiols supported on silica gel and other solid supports to remove selected monovalent and divalent metals from aqueous standard solutions to achieve similar results. This study also reports the significance and results of an investigation involving the use of bifunctional compounds, such as 2-mercaptoethanol, to chemically attach and modify the silica gel, montmorillonite KSF, and magnetite, and subsequently be used in the uptake of selected heavy metals such as copper(II), cadmium(II), lead(II), nickel(II) and silver(I) ions