Influence of Crude Oil and Refined Petroleum Products on Soil Dehydrogenase Activity1
- W. T. Frankenberger and
- J. B. Johanson2
The effects of crude oil, leaded gasoline, kerosene, diesel fuel, and motor oil on soil dehydrogenase activity were investigated by contaminating three soils at three loading rates (20, 40, and 60% w/w oil/dry soil) and monitoring the activity up to 30 d of incubation. The levels of dehydrogenase activity in the contaminated soils were dependent on the amount and type of oil added. The highest level of dehydrogenase activity in all soils was observed with a 60% loading rate of crude oil 30 d after incubation. Dehydrogenase activity in soils contaminated with the refined oils (leaded gasoline, kerosene, diesel fuel, and motor oil) was extremely low when compared with the crude oil-treated soils. When all soils were considered, the maximum activity of the dehydrogenase reaction (expressed in µg formazan/g soil per 24 h) was as follows: crude oil, 1,180; leaded gasoline, 56; kerosene, 32; diesel fuel, 56; and motor oil, 37. Generally, the maximum level of activity was observed at 30 d of incubation in the presence of crude oil, and at 7 d in the presence of refined oils. The increase in dehydrogenase activity was in proportion to the rates of oil application, in that activity increased with increasing loading rates. The lowest level of dehydrogenase activity (0.5 µg formazan/g soil per 24 h) was observed in the kerosene-treated soils. These results suggest that any influence the oils may have on soil dehydrogenase activity is dependent on the chemical composition of the oil itself. The additives present in refined oils may have a major influence on the dehydrogenase reaction in soils.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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