N-Methylpyrrolidone (NMP) is a cyclic nitrogen-containing organic chemical used to replace more volatile and toxic organic solvents in paint coating and cleaning applications. The Marine Corps Multi-Commodity Maintenance Center was concerned that the high NMP and organic levels in process water would upset treatment processes at the Industrial Process Water Plant (IWP). The NMP contaminated process water was oxidized by a semicontinuous advanced oxidation reactor to reduce the organic concentration. The oxidative byproducts of NMP were identified by GC/MS and tested for their toxicity. A toxicity test, utilizing the Microtox toxicity assay, revealed that methylsuccinimide was the most toxic identifiable product of NMP oxidation. The toxicity of the process water was reduced as methylsuccinimide and was further oxidized to succinimide and other amine products. The results indicate that NMP contaminated process water should be oxidized past the N-methylsuccinimide compound prior to standard industrial process water treatment procedures, so as to reduce toxicity concerns associated with NMP contaminated process water.
An enclosed flow-through system using airborne ozone for disinfection and which removes the ozone with a catalytic converter was tested with a strain of Escherichia coli. Petri dishes containing the microorganisms were inserted in a chamber and exposed for 10-480 min to ozone concentrations between 4 and 20 ppm. Death rates in excess of 99.99% were achieved. Survival data is fitted to a two-stage curve with a shoulder based on the multihit target model. Ozone was removed from the exhaust air to nondetectable levels using a metal oxide based catalyst. The possibility of using ozone as an airborne disinfectant for internal building surfaces and catalytically removing the ozone on exhaust is demonstrated to be feasible. A model for the decay of Bacillus cereus under ozone exposure is proposed as an example for predicting the sterilization of buildings contaminated with anthrax. The potential for disinfecting airstreams and removing ozone to create breathable air is also implied by the results of this experiment.
Experiments were conducted on arsenic and lead volatility from simulated slags containing either arsenic or lead. Samples were exposed to temperatures up to 900 C and atmospheres that were inert, oxidizing, reducing, or contained hydrogen chloride. Both arsenic and lead deposited within the system during the experiment, requiring a cleaning procedure to remove and capture the metal for measurement. Arsenic or lead volatility increased with increasing treatment time, temperature, and CO concentration. Lead volatility also increased with increasing HC1 concentration. The arsenic volatilized was two orders of magnitude less than lead for the same experimental conditions. The results show that under conditions similarly occurring in a hazardous waste incinerator, arsenic in a slag is relatively involatile, and only a small fraction of either arsenic or lead is volatilized.
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