Chromium, an element of widespread use, is toxic in some
forms. Improper disposal of waste chromium products has
resulted in contamination of many sites throughout the United
States, including the United Chrome Products Superfund site
in Corvallis, Oregon. A better understanding of chromium
chemistry is needed to facilitate the remediation...
Chromium spills on soils are causing severe groundwater contamination
problems. To increase the performance of cleanup methods, the chemical behavior
of chromium in soils and its transport through soils have to be understood. The
objectives of this research were to investigate the sorption characteristics of
chromium(VI) in soil and to...
Soil column studies were performed on a chromium contaminated soil from the United
Chrome Products Superfund Site currently undergoing a pump-and-treat cleanup process. The
goal of the research was to provide insight into the feasibility of chemically changing the injection
fluid of the pump-and-treat system to enhance hexavalent chromium (Cr(VI))...
A study of phosphorus loading and water quality implications was conducted for
the Oregon coastal lakes. The study was based on existing data for lake total phosphorus
concentrations and for watershed land uses. A phosphorus mass-balance model was
developed to predict lake total phosphorus concentrations from estimated phosphorus
loading from...
Several potential sorbent materials containing iron oxides were prepared and evaluated for potential to remove divalent metals from waste waters. These included a ferrihydrite-coated sand, maghemite incorporated in Dowex[Trademark] ion exchange resin, gothite and two thermally activated ferrihydrites. Attempts to prepare sorbents from steel shot by coating with ferrihydrite or...
The City of Salem, Oregon has an active sewer main chemical grouting
program for the control of groundwater infiltration into the sewer collection
system. The effectiveness of this chemical grouting program is evaluated
by a comparison to other effective chemical grouting programs for control
of inflow/infiltration (I/I). The importance of...
A simple heat exchanger network has been studied as
an example of a dynamically interactive process. The
process is relatively simple, requiring only temperature
measurements and flow rate manipulations. Equations are
presented for the design of a physical process having a
specified steady-state Relative Gain Array and specified
dynamic characteristics....
