A screening protocol for bioremediation of contaminated soil

Bioremediation of oil‐contaminated soil in Kuwait. I. landfarming to remediate oil‐contaminated soil

“…Although most of the PAH reductions were due to losses of the three-and four-ring compounds, considerable reductions were ob- served in the concentrations of five-ring compounds. As reported in the literature, most simple petroleum hydrocarbons, phenols, and lower PAHs are degraded rapidly under aerobic conditions (Rogers et al, 1993;Bradford and Krishnamoorthy, 1991). Although low-molecular-weight PAHs are readily degraded, high-molecular-weight PAHs of five or more rings tend to resist extensive bacterial degradation in soil.…”

“…Many oil components are highly hydrophobic and have relatively low solubilities in water. Low water solubility can also inhibit hydrocarbon degradation, which generally occurs in the aqueous phase where the bacteria are present and whose assimilation of substrate and nutrients can easily occur (Rogers et al, 1993).…”

Hexachlorobenzene dechlorination as affected by nitrogen application in acidic paddy soil

“…2a and b, it seems that proper amount of NH 4 + -N application (0.14 g NH 4 HCO 3 -or CO(NH 2 ) 2 -N) accelerated HCB dechlorination, which was attributed to the following two reasonable explanations. Firstly, NH 4 + -N supply can stimulate biodegradation when soil organic carbon is excessive [15,27,28], and the addition of a proper amount of NH 4 + -N probably adjusted soil C/N ratio to a better level for the degraders' activity than the original C/N value. Secondly, there were microbes which could involve in anaerobic ammonium oxidation process in paddy soil [29,30], thus the additional NH 4 + -N, as a reductant, might accelerate the reductive dechlorination of HCB.…”

Phenanthrene Removal in a Selected Mexican Soil by the Fungus Penicillium frequentans: Role of C:N Ratio and Water Content

“…Inorganic macronutrients, mainly nitrogen (N) and phosphorous (P), must be present in adequate quantities for cell growth in order to stimulate the degradation of hydrophobic petroleum hydrocarbons (Dibble and Bartha, 1979;Rogers et al, 1993;Rojas-Avelizapa et al, 2000), such as phenanthrene. Therefore, N and P are commonly added to contaminated soil when the target contaminant represents a relative excess of carbon source (Rojas-Avelizapa et al, 2000) or in environments where the concentration of inorganic nutrients may be less than optimal for microbial proliferation or metabolism (Manilal and Alexander, 1991).…”