title: Remediation of oil-based drill cuttings through a biosurfactant-based washing followed by a biodegradation treatment.
abstract: In this study, oil-based drill cuttings were washed by a rhamnolipid solution and then subjected to bioremediation in stainless steel boxes using sawdust as bulking agent. A mixed bacterial culture, mainly containing Pseudomonas, Acinetobacter, Alcaligenes, Agrobacterium, and Comamonas, was used as inoculums. Approximately 83% of organics were removed after washing under optimal conditions (liquid/solid ratio, 3:1; washing time, 20 min; stirring speed, 200 rpm; rhamnolipid concentration, 360 mg/L; temperature, 60 °C), and the total petroleum hydrocarbon concentration of the cuttings dropped from 85,000 to 12,600 mg/kg. In the bioremediation stage, concentrations of saturated and aromatic hydrocarbons decreased to 2140 and 1290 mg/kg, respectively, after 120 days. Ultrahigh-resolution mass spectrometry demonstrated that oxygen- and nitrogen-containing compounds had undergone biodegradation. The results of this study indicate that this two-stage remedial system can reduce treatment time and increase treatment efficiency as compared with a single bioremediation or washing treatment.
authors.affiliation: State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yan
authors.forename: Mang
authors.initials: M
authors.lastname: Lu
authors.forename: Yueming
authors.initials: Y
authors.lastname: Guan
authors.forename: Weimu
authors.initials: W
authors.lastname: Zhang
authors.forename: Zhongzhi
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005452:Fluoresceins / Q000737:chemistry; D006017:Glycolipids / Q000737:chemistry; D009930:Organic Chemicals / Q000302:isolation & purification; D010578:Petroleum / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D005452:Fluoresceins; D006017:Glycolipids; D009930:Organic Chemicals; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D013501:Surface-Active Agents; C418382:rhamnolipid; C018506:diacetylfluorescein