title: Utilization of phosphogypsum in tannery sludge stabilization and evaluation of the radiological impact.
abstract: The current global trend towards increasingly stringent environmental standards and efforts for efficient utilization and re-use of available by-products and/or wastes, favors the use of low-cost sorbent materials for the treatment of heavy metal-contaminated solid wastes. In this study, the stabilization of tannery sludge, produced from the physicochemical and biological treatment of tannery wastewaters, was examined by the addition of phosphogypsum (PG) at a ratio of 1:1. Characterization of the tannery sludge leachates showed high amounts of chromium which exceeded the acceptable level for disposal in non-hazardous waste landfills, while the dissolved organic carbon (DOC) concentrations exceeded the limits for disposal in landfills for hazardous wastes, according to the EU Decision 2003/33/EC. Leachates of the waste stabilized with PG presented chromium and DOC concentrations below the regulation limits for disposal in landfills for non-hazardous wastes. Moreover, mixing PG with tannery sludge resulted in a stabilized waste with reduced radioactivity.
authors.affiliation: Department of Chemistry, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Pantazopoulou
authors.forename: O
authors.initials: O
authors.lastname: Zebiliadou
authors.forename: F
authors.initials: F
authors.lastname: Noli
authors.forename: M
authors.initials: M
authors.lastname: Mitrakas
authors.forename: P
authors.initials: P
authors.lastname: Samaras
authors.forename: A
authors.initials: A
authors.lastname: Zouboulis
mesh_terms: D002133:Calcium Sulfate / Q000737:chemistry*; D002857:Chromium / Q000032:analysis*; D004553:Electric Conductivity; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005062:European Union; D006256:Hazardous Waste / Q000032:analysis* / Q000331:legislation & jurisprudence; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D010758:Phosphorus / Q000737:chemistry*; D013051:Spectrometry, Gamma; D013633:Tanning; D062065:Wastewater / Q000032:analysis*
chemical_list: D002133:Calcium Sulfate; D002857:Chromium; D006256:Hazardous Waste; D007220:Industrial Waste; D010758:Phosphorus; D062065:Wastewater; C077769:phosphogypsum