The purpose of this study was to determine the conditions under which removal of the tasteand odor-causing compounds geosmin and 2-methylisoborneol (MIB) by powdered activated for effective removal of MIB and geosmin, carbon (PAC) was most efficient. It was observed that a PAC dosage as low as 5 mg/L could l a study of the effects of initial reduce commonly occurring concentrations of these organics (up to 20 rig/L)) to acceptable concentrations of the organics on relevels. Chlorine and monochloramine residuals appeared to have an adverse effect on the moval efficiency, l adsorption of geosmin and MIB by PAC, as did the presence of background humic acid.

No abstract

Motorized recreational watercraft were the predominant mode of contamination in reservoirs. Methyl tertiary butyl ether (MTBE) is a common fuel oxygenate used in motor vehicle fuels to control emissions and boost octane. It is more water‐soluble than other fuel constituents and does not adsorb well to substrates such as soil. It can contaminate groundwater supplies through leaking underground fuel storage tanks and pipelines, and through spills, urban storm runoff, and precipitation. It can also contaminate open water reservoirs through exhaust from motorized watercraft. The Metropolitan Water District of Southern California surveyed six reservoirs that supply drinking water in Southern California. Recreation on these reservoirs ranged from none at all to high activity with personal watercraft. It was found that motorized watercraft can contribute a significant amount of MTBE to the water supply.

A pilot-scale study of ozone and PEROXONE (ozone in combination with hydrogen peroxide) for the removal of the odorous compounds 2-methylisoborneol (MIB) and geosmin in drinking water has been conducted at the Metropolitan Water District of Southern California. The study investigated the effects of ozone dosage, ratio of hydrogen peroxide to ozone (H202/03), and contact time. It was found that MIB and geosmin removal increased with higher applied ozone doses, but longer contact times over the range of 6-12 min were not significant. It was determined that 80-90 percent removal could be achieved with an ozone dose of approximately 4.0 mg/l, as compared to an ozone dose of approximately 2.0 mg/l at a H202/03 ratio of 0.2. Also investigated were the effects of alternative contactor configurations, ferrous sulfate as an alternative coagulant, bromide and ammonia addition, and simulated turbidity on the removal efficiencies of the two odorous compounds.

The purpose of this study was to determine the conditions under which removal of the taste‐ and odor‐causing compounds geosmin and 2‐methylisoborneol (MIB) by powdered activated carbon (PAC) was most efficient. It was observed that a PAC dosage as low as 5 mg/L could reduce commonly occurring concentrations of these organics (up to 20 ng/L) to acceptable levels. Chlorine and monochloramine residuals appeared to have an adverse effect on the adsorption of geosmin and MIB by PAC, as did the presence of background humic acid. Filtration rate and contact time did not significantly affect removal efficiency.