Chemistry Project 2008
ECoS Faculty: Ken Feldman and Jackie Bortiatynski
ECoS Undergraduate Mentor: Ryan Bisbey
Environmental Remediation
The removal of contaminants from water favorably impacts both the quality of the water
and the quality of life for all of the organisms that use that water. This broad user group extends
from humans, or course, all the way down to fish and other aquatic life. One of the commonly
used technologies for impurity removal from water reservoirs involves passing the water through
a bed of Granular Activated Carbon (GAC), which has pores and surface properties that favor
binding of many organic contaminants, leading to their removal from the water stream. This
technology is employed from a massive scale for potable drinking water production to a small
scale for cleaning up aquarium water in people's fish tanks. In this laboratory-scale experiment,
you will use GAC's prepared from different sources to remove colored dyes from water. These
colored dyes have structural similarities to actual common water impurities, and their bright
color makes them easy to visualize and measure. The dye removal in your water reservoir will
be monitored by UV/VIS (ultraviolet-visible) spectroscopy as a function of time. The data
collected will be fit to a mathematical model for dye removal, and this data fitting will allow
calculation of a single number that expresses the rate (speed) by which dye is removed by the
GAC: this number is called a "rate constant". Comparing rate constants from different dye
molecules and the same GAC will permit conclusions about which type of chemical impurity is
removed from water the fastest; in addition, comparing rate constants between different GAC
samples with the same dye will allow conclusions to be drawn about which GAC is the fastest (=
best) at removing that dye. Overall, you will learn (1) about how the chemical (structural)
characteristics of a molecule can affect its ability to bind (= adhere) to a surface, (2) how to run a
UV/VIS spectrophotometer, (3) about mathematical models for physical processes, and why
modeling is useful for drawing scientific conclusions, and (4) presenting scientific data and the
derived conclusions to a non-scientific audience.