Abstract |
The U.S. Environmental Protection Agency (EPA) has been examining the potential for combining sonication with other technologies for monitoring specific classes of organic pollutants in water. Pollutants are decomposed into ions which can be detected using known electrochemical techniques. An increase in concentration of the target ion after sonication indicates the presence of the pollutant. The paper presents additional results on the use of sonochemistry in monitoring carbon tetrachloride, chloroform, and trichloroethylene (TCE) in water. Relationships were examined for changes in chloride ion and pH upon sonication versus concentration of the individual organochlorine pollutants. Another issue deals with the effect of various humic acids (at different concentrations) on changes in Cl-pH, and conductivity, as a result of sonicating solutions of the pollutants. Linear relationships with excellent correlation coefficients were found between increases of Cl- (after sonications) and 3-80 ppm concentrations of CCI4, CHCI3 and TCE in water. The pH was found to decrease in all cases, and the relationships were nonlinear. Three different humic acids were examined in concentrations up to 400 ppm for effects on Cl- yield, pH changes, and conductivity changes. There were no differences in Cl- yield relative to control solutions of chlorinated hydrocarbons in deionized water. However, conductivity and pH changes were smaller. |