Technical Assistance. Mass Spectrometer Oil Monitoring System

The results of field testing of currently available hardware for the treatment of oily bilge and ballast wastewaters and experimental hardware employing ultraviolet radiation in the presence of ozone are presented in this two-part report. Samples of untreated bilgewater and treated bilgewater processed through off-the-shelf oil-water separators (coalescers) were collected from 10 different Army watercraft including large ships, landing craft, tugs, and barges. The samples were analyzed for suspended and dissolved pollutants. The results showed that generally the untreated bilgewater from the larger ships contained suspended pollutants in lower concentrations than the other classes of watercraft. It is speculated that the easier maintenance and larger bilgewater volume on these vessels accounts for the difference. The oil-water separators were effective in reducing the suspended pollutant levels in bilgewater. On the average, 77.8% of the suspended pollutants were removed by the process. However, there exists a wide disparity in the performance of the oil-water separators from watercraft to watercraft. The data suggest that the varied performance may be due to procedural variations between watercraft (e.g., bilge cleaning procedures, bilgewater handling procedures, maintenance procedures), or because of faulty oil-water separator elements. Recommendations are made that would lead to identifying the factors causing poor performance and eliminating them so that all oil-water separators will consistently produce high-quality bilgewater effluent.