Distribution of intermediates during removal of benzene from aqueous solutions by low energy electron beam

This paper presents results from an experiment that utilizes a low energy electron beam apparatus for the removal of benzene from an aqueous solution. The configuration of the irradiator is briefly described, a significant detail of which is the use of boron nitride windows. Concentrations of benzene and its oxidation by-products including phenols, aldehydes and carboxylic acids were monitored throughout the experiment. No analysis was undertaken for by-products formed from reductive pathways. Phenolic intermediates were formed first followed by the development of organic acid intermediates. Aldehydes were only formed to a minor extent. All of these oxidation by-products together account for nearly 30% of the total organic carbon of the parent compound. However, at the time when benzene was degraded to non detect levels, intermediates were still present in significant amounts. These intermediates were detected in the following relative distribution: 90% were carboxylic acid intermediates, followed by phenols with 9% and aldehydes with 1%.