title: Combining in situ chemical oxidation, stabilization, and anaerobic bioremediation in a single application to reduce contaminant mass and leachability in soil.
abstract: Laboratory batch reactors were maintained for 32 weeks to test the potential for an in situ remedy that combines chemical oxidation, stabilization, and anaerobic bioremediation in a single application to treat soil from a manufactured gas plant, contaminated with polycyclic aromatic hydrocarbons (PAH) and benzene, toluene, ethylbenzene, and xylenes (BTEX). Portland cement and slaked lime were used to activate the persulfate and to stabilize/encapsulate the contaminants that were not chemically oxidized. Native sulfate-reducing bacteria degraded residual contaminants using the sulfate left after persulfate activation. The ability of the combined remedy to reduce contaminant mass and leachability was compared with NaOH-activated persulfate, stabilization, and sulfate-reducing bioremediation as stand-alone technologies. The stabilization amendments increased pH and temperature sufficiently to activate the persulfate within 1 week. Activation with both stabilization amendments and NaOH removed between 55% and 70% of PAH and BTEX. However, combined persulfate and stabilization significantly reduced the leachability of residual BTEX and PAH compared with NaOH activation. Sulfide, 2-naphthoic acid, and the abundance of subunit A of the dissimilatory sulfite reductase gene (dsrA) were used to monitor native sulfate-reducing bacteria, which were negatively impacted by activated persulfate, but recovered completely within weeks.
authors.affiliation: Department of Geosciences, Western Michigan University, Kalamazoo, MI 49008, USA. Electronic address: daniel.cassidy@wmich.edu.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Cassidy
authors.affiliation: CH2M HILL, 125S Wacker, Ste 3000, Chicago, IL 60606, USA. Electronic address: vipul.srivastava@ch2m.com.
authors.forename: Vipul J
authors.initials: VJ
authors.lastname: Srivastava
authors.affiliation: We Energies, 333W Everett St., A231, Milwaukee, WI 53203, USA. Electronic address: frank.dombrowski@we-energies.com.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Dombrowski
authors.affiliation: Electric Power Research Institute (EPRI), 4927W Willow Road, Brown Deer, WI 53223, USA. Electronic address: jlingle@epri.com.
authors.forename: James W
authors.initials: JW
authors.lastname: Lingle
mesh_terms: D000693:Anaerobiosis; D001554:Benzene / Q000032:analysis; D001555:Benzene Derivatives / Q000032:analysis; D001673:Biodegradation, Environmental; D003252:Construction Materials; D060587:Groundwater; D006863:Hydrogen-Ion Concentration; D009281:Naphthalenes / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D012972:Sodium Hydroxide / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D013431:Sulfates / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry; D013696:Temperature; D014050:Toluene / Q000032:analysis; D014873:Water Pollutants / Q000032:analysis; D014992:Xylenes / Q000032:analysis
chemical_list: D001555:Benzene Derivatives; D009281:Naphthalenes; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D013431:Sulfates; D013440:Sulfides; D014873:Water Pollutants; D014992:Xylenes; D014050:Toluene; D012972:Sodium Hydroxide; D001554:Benzene; C004912:ethylbenzene; C030037:2-naphthoic acid; D010100:Oxygen
keywords: BTEX; Leachability; PAH; Persulfate; Stabilization; Sulfate-reducing bacteria