title: Electrokinetic-enhanced bioaugmentation for remediation of chlorinated solvents contaminated clay.
abstract: Successful bioremediation of contaminated soils is controlled by the ability to deliver bioremediation additives, such as bacteria and/or nutrients, to the contaminated zone. Because hydraulic advection is not practical for delivery in clays, electrokinetic (EK) injection is an alternative for efficient and uniform delivery of bioremediation additive into low-permeability soil and heterogeneous deposits. EK-enhanced bioaugmentation for remediation of clays contaminated with chlorinated solvents is evaluated. Dehalococcoides (Dhc) bacterial strain and lactate ions are uniformly injected in contaminated clay and complete dechlorination of chlorinated ethene is observed in laboratory experiments. The injected bacteria can survive, grow, and promote effective dechlorination under EK conditions and after EK application. The distribution of Dhc within the clay suggests that electrokinetic transport of Dhc is primarily driven by electroosmosis. In addition to biodegradation due to bioaugmentation of Dhc, an EK-driven transport of chlorinated ethenes is observed in the clay, which accelerates cleanup of chlorinated ethenes from the anode side. Compared with conventional advection-based delivery, EK injection is significantly more effective for establishing microbial reductive dechlorination capacity in low-permeability soils.
authors.affiliation: Civil and Environmental Engineering Department, Northeastern University, Boston, MA 02115, USA. x.mao@neu.edu
authors.forename: Xuhui
authors.initials: X
authors.lastname: Mao
authors.forename: James
authors.initials: J
authors.lastname: Wang
authors.forename: Ali
authors.initials: A
authors.lastname: Ciblak
authors.forename: Evan E
authors.initials: EE
authors.lastname: Cox
authors.forename: Charlotte
authors.initials: C
authors.lastname: Riis
authors.forename: Mads
authors.initials: M
authors.lastname: Terkelsen
authors.forename: David B
authors.initials: DB
authors.lastname: Gent
authors.forename: Akram N
authors.initials: AN
authors.lastname: Alshawabkeh
mesh_terms: D000538:Aluminum Silicates / Q000032:analysis*; D041862:Chloroflexi / Q000235:genetics / Q000378:metabolism; D000077215:Clay; D004563:Electrochemistry; D004787:Environmental Pollution; D052918:Environmental Restoration and Remediation; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000737:chemistry; D010084:Oxidation-Reduction; D010539:Permeability; D060888:Real-Time Polymerase Chain Reaction; D012988:Soil Microbiology; D012997:Solvents; D055549:Volatile Organic Compounds / Q000032:analysis; D014867:Water / Q000032:analysis
chemical_list: D000538:Aluminum Silicates; D006843:Hydrocarbons, Chlorinated; D007773:Lactates; D012997:Solvents; D055549:Volatile Organic Compounds; D014867:Water; D000077215:Clay