Denitrification of Nitrate-Containing Heavy-Metal-Filtrate Solutions

摘要

Applying the basis of Oak Ridge Y-12 Plant's development program of biodenitrification of high strength nitrate wastes, the Paducah Gaseous Diffusion Plant (PGDP) has extended that technology to encompass usage of a concentrated nitrate-containing heavy metal filtrate as the feed solution. The results of this paper indicate that while biodenitrification of the PGDP heavy metal wastes has reduced the nitrate concentration from 129,000 ppM to 10 ppM, the rate of denitrification attained in the Y-12 experiments has not been duplicated. Although batch treatment of the heavy metal filtrate proved successful at a low denitrification rate, continuous operation was not accomplished due to the accumulation of heavy metals in the sludge and the high metal content of the feed solution. Effects of the heavy metal solution filtrate as the biodenitrification feed solution are presented in this report in relation to reactor operation and performance. An economic evaluation of a typical plant scale biodenitrification system, using present generation rates, would result in a disposal cost of greater than $250/barrel. Current conditions suggest that sale of this waste to a metals recovery firm or reuse within the Nuclear Division should be explored as an alternative to biodenitrification. (ERA citation 06:034379)