CHARACTERIZATION OF PHOSGEN-FREE MIC WASTE-WATER

A high strength wastewater containing persistent compounds is generate d from the phosgen-free MIC(methylisocyanate) process. To get some bas ic information prior to developing effective treatment methods, the wa stewater was characterized by identifying the components, evaluating t heir biodegradabilities, and toxicities. Four components were extracte d from the wastewater and found to be tirmethylisocyanurate (TMIC), tr imethylbiuret (TMBU), dimethylurea (DMU), and tetramethylurea (TMU) by comparing the GC-MS and FTIR spectra of them with those of the propos ed authentic compounds. Their toxicities by Microtox test were not so serious that their effect on the aquatic environment were expected ins ignificant. The biodegradability test results showed that TMIC, TMBU a nd TMU were rarely degraded biologically while DMU was readily decompo sed releasing ammonia as a metabolite.