Kinetic modeling of carbon tetrachloride, chloroform and methylene chloride removal from aqueous solution using the electron beam process

An innovative treatment process using high energy electrons has been shown to be effective for the destruction of various toxic (regulated) organic chemicals. This paper presents data for the destruction of chlorinated methanes, carbon tetrachloride, chloroform and methylene chloride in treated groundwater. The studies were conducted at pilot scale, using a 75 kW electron beam at a flow rate of 0.38 m3 min−1. This study examined the effect of solute concentration and total alkalinity on removal efficiency. A kinetic model was used to describe the results of single solute experiments of the three chlorinated methanes. These model predictions were then compared to experimental results and showed a varying degree of predictability for the three compounds. These calculations suggest that the initial reactions which eventually lead to the mineralization of the three chlorinated methanes result primarily from aqueous electron initiated reactions. The subsequent reaction between O2 and the carbon centered radicals with the formation of alkyl peroxides also appears important for their ultimate decomposition.