Removal of heavy metals from water with forest based materials
For 1.5 to 2.5 billion people in the world, clean water is a critical issue (Lepkowski 1999). In the U.S., it is estimated that 90% of all Americans live within 10 miles of a body of contaminated water (Hogue, 2000). The development of filters to clean our water supply is big business. It is estimated that global spending on filtration (including dust collectors, air filtration, liquid cartridges, membranes and liquid macro-filtration) will increase from $17 billion in 1998 to $75 billion by 2020 (Noble, 2000). The fastest-growing non-industrial application area for filter media is for the generation of clean water. One of the prevalent contaminates in our water is metal ions that come from a wide variety of sources including abandoned hard rock and coal mines, highways and large parking lot runoff and natural erosion of minerals. Most methods to remove metal ions from solution are expensive. However, it has been shown that wood and bark are effective in removing metal ions from water (Bryant et al., 1992; Kumar and Dara, 1980; Laszlo and Dintzis, 1994; Randall, 1977).