title: Effective remediation of grossly polluted acidic, and metal-rich, spoil heap drainage using a novel, low-cost, permeable reactive barrier in Northumberland, UK.
abstract: A permeable reactive barrier (PRB) for remediation of coal spoil heap drainage in Northumberland, UK, is described. The drainage has typical chemical characteristics of pH<4, [acidity]>1400 mg/L as CaCO3, [Fe]>300 mg/L, [Mn]>165 mg/L, [Al]>100mg/L and [SO4]>6500 mg/L. During 2 years of operation the PRB has typically removed 50% of the iron and 40% of the sulphate from this subsurface spoil drainage. Bacterial sulphate reduction appears to be a key process of this remediation. Treatment of the effluent from the PRB results in further attenuation; overall reductions in iron and sulphate concentrations are 95% and 67% respectively, and acidity concentration is reduced by an order of magnitude. The mechanisms of attenuation of these, and other, contaminants in the drainage are discussed. Future research and operational objectives for this novel, low-cost, treatment system are also outlined.
authors.affiliation: Hydrogeochemical Engineering Research and Outreach Group, Institute for Research on Environment and Sustainability, Devonshire Building, University of Newcastle, Newcastle upon Tyne NE1 7RU, UK. a.p.jarvis@ncl.ac.uk
authors.forename: A P
authors.initials: AP
authors.lastname: Jarvis
authors.forename: M
authors.initials: M
authors.lastname: Moustafa
authors.forename: P H A
authors.initials: PH
authors.lastname: Orme
authors.forename: P L
authors.initials: PL
authors.lastname: Younger
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D004739:England; D004784:Environmental Monitoring / Q000379:methods; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007501:Iron; D019216:Metals, Heavy; D008906:Mining; D010539:Permeability; D011891:Rain; D013431:Sulfates; D018505:Waste Management; D014872:Water Movements; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D019216:Metals, Heavy; D013431:Sulfates; D014874:Water Pollutants, Chemical; D007501:Iron