Investigation into the use of chicken manure to enhance the biodegradation of total petroleum hydrocarbons.

The use of chicken manure to enhance the biodegradation of total petroleum hydrocarbons (TPH) in composting bioremediation was investigated to help develop an improved understanding of the chemical, biological and toxicological processes involved. Treatability studies combined with an extensive suite of laboratory analyses were designed and undertaken whereby naturally contaminated oil refinery sludge was either amended with chicken manure or left unamended for a total duration of 90 days. The effects of chicken manure on the biodegradation of fractionated aliphatic and aromatic hydrocarbons, differentiation between biostimulation and bioaugmentation effects of chicken manure, and the potentially detrimental effects of chicken manure on the bioremediation process through the introduction and adverse proliferation of non-hydrocarbon degrading microorganisms and the potential introduction of compounds that may elicit toxic effects on hydrocarbon degrading microorganisms were monitored over the duration of the treatability studies using a combination of chemical, toxicity and microbial laboratory analyses. This study found that the addition of chicken manure enhanced the degradation of C9-C12 aliphatic hydrocarbons. It was found that this reflects a combination of biostimulation and bioaugmentation effects and that volatilisation was minimal. This investigation also found that the addition of chicken manure can have positive effects on bioremediation as evident by the enhancement of conditions for microbial growth and/or activity, introduction and enhanced growth of potential hydrocarbon degrading bacterial populations, and the enhanced reduction in toxicity of methanol extractable hydrocarbons. However, it was found that the addition of chicken manure was seen to cause an increase in toxicity of total leachable compounds, which may present a risk to TPH biodegradation through potential toxic effects on hydrocarbon degrading microorganisms. It is concluded from this study that there is a potential for the use of chicken manure to enhance TPH biodegradation, but that this is likely restricted to low molecular weight hydrocarbons