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USE OF SONOCHEMISTRY IN MONITORING CHLORINATED HYDROCARBONS IN WATER
Citation:
Orzechowska, G. E., E. J. Poziomek, V. F. Hodge, AND W. Engelmann. USE OF SONOCHEMISTRY IN MONITORING CHLORINATED HYDROCARBONS IN WATER. Environmental Science and Technology 29(5):1373-1379, (1995).
Description:
The U.S. Environmental Protection Agency (EPA) has been examining the potential of combining sonication with available measurement technologies for monitoring chlorinated hydrocarbons in water. The chloride ion (C1-) concentration, conductivity, and pH were measured before and after sonication. C1- could be detected in aqueous solutions of 3-80 ppm carbon tetrachloride (CC14), chloroform (CHC13), and trichloroethylene (TCE) after 1 min of sonication. The increases of C1- were accompanied by increases in conductivity and decreases in pH. The conductivity changes were higher than expected based on measured C1-. Ion chromatography of solutions before and after sonication showed that formate ion (HCOO-) was also formed. Other ions may have formed as well, but the concentrations were too low to allow their detection relative to HCOO- and C1-. The results achieved serve as proof-of-principle and form a base of information which can be used to develop ultrasound monitoring methods for these compounds. Aromatic and polyaromatic chloro compounds represented by chlorobenzene (Ph-C1)and polychlorobiphenyls (PCBs), respectively, did not release C1- upon sonication as readily as did CC14, CHC13, and TCE. The PCB solutions gave no measurable changes in either C1-, conductivity, or pH under the conditions of the experiments described.