The fate of diesel hydrocarbons in soils and their effect on the germination of perennial ryegrass

Abstract

Hydrocarbon contamination in soils may be toxic to plants and soil microorganisms and act as a source of groundwater contamination. The objective of this study was to evaluate the fate of diesel in soils with or without added nutrients. The soils examined either had or had not a previous history of hydrocarbon contamination. Particular aspects examined were soil respiration, changes in microbial population, breakdown of diesel hydrocarbons, and phytotoxicity to the germination of perennial ryegrass. Soil respiration was measured as evolved CO2. Bacterial population was determined as colony forming units in dilution plates and fungal activity was measured as hyphal length. The fate of individual hydrocarbons was determined by gas chromatography-mass spectrometry after extraction with dichloromethane. When diesel was added to soil with no previous history of hydrocarbon contamination at rates up to 50 mg/g, the respiration response showed a lag phase of 6 days and maximum respiration occurred at day 11. The lag phase was 2 days and maximum respiration occurred at day 3 in soil with a previous history of hydrocarbon contamination. After the peak, respiration decreased up to about 20 days in both soils. Thereafter, respiration become more or less constant but substantially greater than the control. N and P addition along with diesel did not reduce the lag phase but increased the respiration over the first 20 days of incubation. Diesel addition with or without N and P increased the bacterial population 10- to 100-fold but fungal hyphal length did not increase. Diesel addition at a rate of 136 mg/g did not increase the microbial population. Removal of inhibition to germination of perennial ryegrass was linked to the decomposition of nC10 and nC11 hydrocarbons and took from 11 to 30 days at diesel additions up to 50 mg/g depending on the soil. Inhibition to germination of perennial ryegrass persisted to more than 24 weeks at the 136 mg/g of diesel addition.

Effects of motor oil pollution on soil and seedling growth of parkinsonia aculeata l.

“…The release of crude oil into the environment by oil spills is receiving worldwide attention (Millioli et al, 2009). The toxic effects of spent engine oil on germination of perennial rye grass, Amaranthus hybridus and maize growth performance was reported (Isirimah et al, 1989;Odjegba and Sadiq, 2002;Siddique and Adams, 2002). This study demonstrated that motor oil application at high concentration in soil has significant effect on the seedling growth performance of P. aculeata.…”

Impact of hydrocarbons from a diesel fuel on the germination and early growth of subantarctic plants

“…During hydrocarbon exposures, acute toxicity is likely caused by lighter, more volatile hydrocarbons with a lower equivalent carbon number; heavy fractions with a high equivalent carbon number are more likely to cause chronic toxic effects [34][35][36][37]. Toxicity of petroleum hydrocarbons is strongly correlated with hydrocarbon fractions that have lower boiling points and octanol-water coefficients [log(K ow )], especially those within the nC10-nC19 range [12,[37][38].…”

Isolation and characterization of an n-hexadecane degrading Acinetobacter baumannii KSS1060 from a petrochemical wastewater treatment plant

“…Soil and water remediation by non-biological technologies are expensive and incomplete (Medina-Bellver et al 2005;Siddiqui and Adams 2002). Moreover, bioremediation technology, the use of microorganisms to remove or detoxify contaminations, is a cost-effective and noninvasive method (Siddiqui and Adams 2002) and is highly efficient and can remove even trace levels of contaminants (Okoh 2006).…”

“…Moreover, bioremediation technology, the use of microorganisms to remove or detoxify contaminations, is a cost-effective and noninvasive method (Siddiqui and Adams 2002) and is highly efficient and can remove even trace levels of contaminants (Okoh 2006). However, it has been revealed that natural populations of microorganisms are able to remove environmental hydrocarbon pollutants including the products of petroleum industry, due to their diverse metabolic capabilities (Barin et al 2014).…”