No abstract

Three odorants, geosmin (earthy), MIB (2-methylisoborneol) (musty), and IPMP (2-isopropyl-3-methoxypyrazine) (decaying vegetation/musty) were spiked into raw water taken from the Detroit River and subjected to bench-scale ozonation (with and without hydrogen peroxide). Statistical experiment design was employed to investigate operating variables such as ozone dose, ozone addition point, temperature, odorant spike level, and presence of hydrogen peroxide. Two additional odorants, cis-3-hexenyl acetate (grassy) and trans,trans-2,4-heptadienal (fishy) were also tested. Results showed that ozonation was capable of mitigating the spiked odorants in the Detroit source water. Ozone dose was the single most important factor in removing the odorants. Presence of hydrogen peroxide (without dose optimization) had a limited effect on odorant removal at tested pH and alkalinity conditions. Ozone application point and water temperature had significant impacts on ozone residual, but not on odorant removal. MIB was most difficult to remove by ozonation among the five spiked odorants.

No abstract

Pollutants loading from non-point and diffuse sources can be the most significant in a watershed. Atmospheric deposition in its three forms (ambient, dry, and wet) have been neglected and thus was not included in watershed approach to water resources management. Often regulatory frameworks for water resources protection have not taken into account atmospheric deposition because little or no data is available. The project undertaken is new and unique in its scope and approach to monitor and measure pollutants in atmospheric deposition and its impact on storm water quality.Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or fluxes of mercury (Hg), cadmium (Cd) and polychlorinated biphenyls (PCBs) in ambient air, precipitation, and runoff. The relationship between the atmospheric deposition and runoff on controlled surfaces was explored for the three pollutants, and the impact of the atmospheric deposition to the toxic chemical loading in runoff was investigated. Atmospheric deposition was found to be the primary mass source of Cd, Hg, and PCBs in runoff from the controlled surfaces.

Non-point and diffuse sources can be the most significant sources of pollutants in a watershed. Atmospheric deposition in its three forms (ambient, dry, and wet) has often been neglected and thus was not included in watershed approach for water resources management. Often regulatory frameworks for water resources protection have not taken into account atmospheric deposition because little or no data is available. The project undertaken is new and unique in its scope and approach to monitor and measure pollutants in atmospheric deposition and its impact on storm water quality within a river watershed.Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or masses in ambient air, precipitation, and runoff for twelve trace metals. These metals include mercury (Hg), cadmium (Cd), antimony (Sb), aluminum (Al), arsenic (As), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn). Meteorological parameters including wind speed, wind direction, temperature, and relative humidity were also measured.This study represents the most complete set of atmospheric concentration and deposition data for trace metals and mercury in an urban watershed at this time. Additionally, this is the first time that mercury together with other trace elements in dry deposition and runoff has been measured in a study of this length. The results of this study provide both the critical information and valuable study approaches to monitor trace metal deposition in urban watersheds.