title: Treatment of petroleum drill cuttings using bioaugmentation and biostimulation supplemented with phytoremediation.
abstract: This study sought to compare the effectiveness of bioaugmentation and biostimulation, as well as the combination of both techniques, supplemented with phytoremediation, in the decontamination of petroleum drill cuttings. Drill cuttings with relatively low concentration of total petroleum hydrocarbons (TPH) and metals were mixed with soil in the ratio 5:1 and treated with three different combinations of the bioremediation options. Option A entailed bioaugmentation supplemented with phytoremediation. Option B had the combination of biostimulation and bioaugmentation supplemented with phytoremediation. While biostimulation supplemented with phytoremediation was deployed in option C. Option O containing the drill cuttings-soil mixture without treatment served as untreated control. Fertilizer application, tillage and watering were used for biostimulation treatment, while spent mushroom substrate (Pleurotus ostreatus) and elephant grass (Pennisetum purpureum) were employed for bioaugmentation and phytoremediation treatment, respectively. The drill cuttings-soil mixtures were monitored for TPH, organic carbon, total nitrogen, pH, metal concentrations, and fungal counts, over time. After 56 days of treatment, there was a decline in the initial TPH concentration of 4,114 mg kg(-1) by 5.5%, 68.3%, 75.6% and 48% in options O, A, B and C, respectively. Generally, higher TPH loss resulted from the phytoremediation treatment stage. The treated options also showed slight reductions in metal concentrations ranging from 0% to 16% of the initial low concentrations. The results highlight the effectiveness of bioaugmentation supplemented with phytoremediation. The combination of bioaugmentation and biostimulation supplemented with phytoremediation, however, may prove better in decontaminating petroleum drill cuttings to environmentally benign levels.
authors.affiliation: a Department of Agricultural and Environmental Engineering , Rivers State University of Science and Technology , Port Harcourt , Nigeria.|b Mechanical Engineering Program, Texas A&M University at Qatar , Doha , Qatar.
authors.forename: Reginald B
authors.initials: RB
authors.lastname: Kogbara
authors.affiliation: a Department of Agricultural and Environmental Engineering , Rivers State University of Science and Technology , Port Harcourt , Nigeria.
authors.forename: Innocent
authors.initials: I
authors.lastname: Ogar
authors.affiliation: a Department of Agricultural and Environmental Engineering , Rivers State University of Science and Technology , Port Harcourt , Nigeria.
authors.forename: Reuben N
authors.initials: RN
authors.lastname: Okparanma
authors.affiliation: a Department of Agricultural and Environmental Engineering , Rivers State University of Science and Technology , Port Harcourt , Nigeria.
authors.forename: Josiah M
authors.initials: JM
authors.lastname: Ayotamuno
mesh_terms: D000363:Agaricales / Q000378:metabolism; D001673:Biodegradation, Environmental; D002244:Carbon / Q000032:analysis; D015169:Colony Count, Microbial; D003666:Decontamination; D005308:Fertilizers; D006838:Hydrocarbons / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D000066388:Oil and Gas Industry; D010316:Particle Size; D031782:Pennisetum / Q000378:metabolism*; D010578:Petroleum; D020076:Pleurotus / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D005308:Fertilizers; D006838:Hydrocarbons; D019216:Metals, Heavy; D010578:Petroleum; D012987:Soil; D012989:Soil Pollutants; D002244:Carbon; D009584:Nitrogen
keywords: Bioremediation; elephant grass; metals; mycoremediation; spent mushroom substrate; total petroleum hydrocarbons