Biodegradation by activated sludge from a municipal wastewater plant of an organophosphonate hydrolysis product of VX: . . . But not a drop to drink (pp.33-35)
Citation:
Schuldt, S. J., A. Janeczko, E. Walters, S. Willison, M. Magnuson, AND L. Racz. Biodegradation by activated sludge from a municipal wastewater plant of an organophosphonate hydrolysis product of VX: . . . But not a drop to drink (pp.33-35). Edition 1, Gwyn Winfield (ed.), CBRNe World. Falcon Communications LTD, Winchester, Uk, 8(1):33-35, (2013).
Impact/Purpose:
Organophosphate chemical warfare agents (CWA) have been used in the past and continue to remain a threat to both national and homeland security. In the event of a CWA attack, it is possible that resulting response efforts will lead to CWA-impacted decontamination wastewater entering a municipal wastewater treatment plant. The fate of CWA compounds in a wastewater treatment plant is not well understood. This study investigated the fate of ethyl methylphosphonic acid (EMPA), a hydrolysis product of VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate), in activated sludge from a laboratory scale sequencing batch reactor. The reactor was fed peptone and sodium acetate to simulate wastewater. Sorption kinetics, sorption equilibrium isotherm and degradation batch experiments demonstrated that EMPA did not sorb to the biomass. Degradation results showed that approximately 30% of the initial concentration of 1 mg L-1 EMPA was degraded, with the degradation limited by a threshold effect. In addition, the results suggest that the nitrifying bacteria may be responsible for the degradation via co-metabolism. Therefore, unless a suitable microbial population is present, possible CWA, degradation products, like EMPA, and similarly sorbed and biodegraded compounds may pass through an activated sludge wastewater treatment plant largely unchanged. These results demonstrate that it cannot be assumed that any particular activated sludge will contain the requisite microbial population.
Description:
Journal Article
