(610a) A Study On Using Pulsed Corona Discharges to Degrade Humic Acid From Drinking Water Sources with and without Titanium Dioxide

One of the possible key organic contaminants for drinking water sources is humic acid; in particular this contaminant is usually found in lakes, rivers and other surface-based drinking water sources [1]. Pulsed Corona Discharges (PCD) has been shown to be effective in the degradation of organic molecules of relative small size such as, for example, phenol. Larger contaminants such as dairy products (mostly proteins-based) also have been shown that can be degraded by the use of high oxidation methods such as PCD (Ibanez, 2004). An example of the next type of contaminant in increasing sizes is the humic acid; preliminary analysis (Camp, 2004) showed minor degradation but not all the parameters were studied. In this research, we focus on a combination of pH, conductivity, and physical aspects of the corona-generating system such as input power, frequency, and electrode distance. Furthermore, the addition of titanium dioxide nanoparticles was also investigated. In order to conduct the analysis, a PCD Reactor of a batch type (well mixed) and with point-to-point electrodes was used. The system has the capability of changing the power as well as the frequency. The electrode chamber allows for the streamer/sparks visualization and electrode-to-electrode distance variation.

It has been found that one of the key physical parameter for a successful degradation of humic acid, for the case of direct PCD, is the electrode-to-electrode distance provided that other parameters are in the "optimal range" of favorable values. To our best knowledge this is the first reported humic acid degradation based on high oxidation methods. In addition, the utilization of titanium dioxides particles does not seem to add any further degradation under the experimental conditions used. In this presentation we will report key aspects of the experiments conducted and offer reasons for the successful degradation as well as possible causes of why the addition of titanium dioxide particles are not able to increase the degradation action under the conditions studied. Further research will be also outlined.