Application of Chemically Accelerated Biotreatment to Reduce Risk in Oil-Impacted Soils

Abstract

Our laboratory is studying various forms and factors of chemically accelerated biotreatment (CAB) for hydrocarbons contaminated soils, i.e. polynuclear aromatic hydrocarbons; benzene, ethylbenzene, toluene, and xylenes (BTEX); and aliphatic moieties. As the biodegradation capacity of the contaminated soils is the decisive parameter in the CAB technology, we are investigating the effects of delivering nutrients (nitrogen and phosphorus moieties) to soils under simulated in-situ conditions to maximize biodegradation. Nitrogen and phosphorus containing compounds that are gases under expected field conditions are a major research area. In order to determine effectiveness of these additions it was necessary to first identify candidate soil that is suitably nutrient-limited. Slurry-phase bioreactors were the method to assess nutrient effects on contaminant degradation under "ideal" conditions, i.e. in systems where issues such as nutrient and contaminant bioavailability are minimized. In order to determine whether the Microtox  solid-phase test would be suitable for assessing the potential toxicity of the E&P soils to be used in remediation experiments and in determinations of environmentally acceptable endpoints, this assay was investigated. All procedures were followed according to manufacturer's instructions, and clean coarse sand (the same sand used to dilute the soil for column experiments) was used as a control. Solid-phase Microtox  analyses proved to be applicable to the experimental systems under study. In addition, soil moisture content (a w) was evaluated in both the nutrient study and the Microtox  evaluation.

Pseudomonas aeruginosa PR23 isolated from oil contaminated soil tolerate and degrades mixture of polyaromatic hydrocarbons and express novel proteins

“…GC-MS analysis showed the presence of 4,5-dihydropyrene and 1,9-dihydropyrene as intermediate metabolites of PAHs degradation. Mycobacterium austroafricanum also yield 1,9dihydropyrene as an intermediate in the degradation of pyrene (Paterek et al 2001). Intermediates detected in our study through GC-MS such as hexadecenoic acid, naphtho[2,1-b] thiophene, 6,7benzothiophene, 6,7-benzoquinoline, 2,9-dimethylphenanthroline, eicosanoic acid, octadecanoic acid, and glycidyl palmitate have also been reported in other studies (Keum et al 2008;Zhang et al 2021).…”