ABSTRACT
Residual oil contents of coastal and estuarine surface waters must be determined to establish an oil pollution data base, monitor changes in oil content with time and relate these changes to polluting sources. A simple flow-through device has been developed which, in conjunction with a skimmer and pump, can process 100 to 200 liters or more of surface water, removing any oil present in a separate phase. Thus concentrated, the oil can be extracted at a laboratory, its quantity and nature determined, and when related to the volume of water processed through the sampler, provide oil concentration data on a time-integrated basis.
Key to the development of this device was identification of a sorbent material which would quantitatively remove oil from a moving water stream and permit simple extraction of that oil in a laboratory. A laboratory apparatus was designed to generate a flowing water stream containing parts per million (ppm) quantities of oil. A number of sorbent materials were examined with this apparatus and several were found effective. Effort was concentrated on the most promising one. Experiments showed that 5–25 ppm oil in a flowing water stream is quantitatively absorbed by the sorbent. The concentrated oil is easily removed from the sorbent with carbon tetrachloride used as solvent and a Soxhlet extractor. The sorbent is regenerated by this process and can be reused many times. Concentration of the extracted oil is determined by infrared spectrophotometry.