Removal of organic compounds from aqueous solutions by electron radiation technique

The paper describes the experiment concerning low and medium energy electron beam water treatment. The design and construction of the lab scale electron beam water treatment apparatus are described. The irradiator can utilize two types of electron permeable windows, namely 15 /spl mu/m or 25 /spl mu/m titanium foils, and 10 /spl mu/m boron nitride ceramic window. The electron beam is generated in high vacuum (<10/sup -5/ Pa). The closed water circulation system enables adjustment of the dose of electron radiation not only by the beam power and flow rate of water but also by varying treatment time. The dependence of relative concentration on absorbed dose of electron radiation is presented for several contaminants, such as trichloroethylene (TCE), benzene, toluene, chloroform and nitrobenzene. The absorbed dose was calculated on the basis of the measurements of the current transmission and electron energy attenuation while the electron beam passes the permeable window. Effect of electron beam power utilization, accelerating voltage and beam current on the removal rate of the contaminants is presented. The obtained results suggest that the relative content of organic contamination decreases exponentially with an increase in the absorbed dose. It has been found that a substantial removal of the investigated contaminants (80-99%) can be obtained for a relatively low voltage range (100-180 kV).