title: Performance of a sequential reactive barrier for bioremediation of coal tar contaminated groundwater.
abstract: Following a thorough site investigation, a biological Sequential Reactive Barrier (SEREBAR), designed to remove Polycyclic Aromatic Hydrocarbons (PAHs) and BTEX compounds, was installed at a Former Manufactured Gas Plant (FMGP) site. The novel design of the barrier comprises, in series, an interceptor and six reactive chambers. The first four chambers (2 nonaerated-2 aerated) were filled with sand to encourage microbial colonization. Sorbant Granular Activated Carbon (GAC) was present in the final two chambers in order to remove any recalcitrant compounds. The SEREBAR has been in continuous operation for 2 years at different operational flow rates (ranging from 320 L/d to 4000 L/d, with corresponding residence times in each chamber of 19 days and 1.5 days, respectively). Under low flow rate conditions (320-520 L/d) the majority of contaminant removal (>93%) occurred biotically within the interceptor and the aerated chambers. Under high flow rates (1000-4000 L/d) and following the installation of a new interceptor to prevent passive aeration, the majority of contaminant removal (>80%) again occurred biotically within the aerated chambers. The sorption zone (GAC) proved to be an effective polishing step, removing any remaining contaminants to acceptable concentrations before discharge down-gradient of the SEREBAR (overall removals >95%).
authors.affiliation: EERC, School of Planning Architecture and Civil Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom. o.gibert@qub.ac.uk
authors.forename: Oriol
authors.initials: O
authors.lastname: Gibert
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Ferguson
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kalin
authors.forename: Rory
authors.initials: R
authors.lastname: Doherty
authors.forename: Keith W
authors.initials: KW
authors.lastname: Dickson
authors.forename: Karen L
authors.initials: KL
authors.lastname: McGeough
authors.forename: Jamie
authors.initials: J
authors.lastname: Robinson
authors.forename: Russell
authors.initials: R
authors.lastname: Thomas
mesh_terms: D000327:Adsorption; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D002244:Carbon / Q000737:chemistry; D003033:Coal Tar; D006841:Hydrocarbons, Aromatic / Q000737:chemistry / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D006841:Hydrocarbons, Aromatic; D009566:Nitrates; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D013431:Sulfates; D014874:Water Pollutants, Chemical; D002244:Carbon; D003033:Coal Tar; D009584:Nitrogen