title: Combined coagulation-flocculation and sequencing batch reactor with phosphorus adjustment for the treatment of high-strength landfill leachate: experimental kinetics and chemical oxygen demand fractionation.
abstract: The treatability of high-strength landfill leachate is challenging and relatively limited. This study examines the feasibility of treating high-strength landfill leachate (chemical oxygen demand [COD]: 7,760-11,770 mg/L, biochemical oxygen demand [BOD5]: 2,760-3,569 mg/L, total nitrogen [TN] = 980-1,160 mg/L) using a sequencing batch reactor (SBR) preceded by a coagulation-flocculation process with phosphorus nutritional balance under various mixing and aeration patterns. Simulations were also conducted to define kinetic parameters and COD fractionation. Removal efficiencies reached 89% for BOD5, 60% for COD, and 72% for TN, similar to and better than reported studies, albeit with a relatively lower hydraulic retention time (HRT) and solid retention time (SRT). The coupled experimental and simulation results contribute in filling a gap toward managing high-strength landfill leachate and providing guidelines for corresponding SBR applications.
  
  
  CONCLUSIONS
  The treatability of high-strength landfill leachate, which is challenging and relatively limited, was demonstrated using a combined coagulation-flocculation with SBR technology and nutrient balance adjustment. The most suitable coagulant, kinetic design parameters, and COD fractionation were defined using coupled experimental and simulation results contributing in filling a gap toward managing high-strength leachate by providing guidelines for corresponding SBR applications and anticipating potential constraints related to the non-biodegradable COD fraction. In this context, while the combined coagulation-flocculation and SBR process improved removal efficiencies, posttreatment may be required for high-strength leachate, depending on discharge standards and ultimate usage of the treated leachate.
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering and Architecture, American University of Beirut, PO. Box 11-0236, Beirut 1107 2020, Lebanon. mfadel@aub.edu.lb
authors.forename: M
authors.initials: M
authors.lastname: El-Fadel
authors.forename: F
authors.initials: F
authors.lastname: Matar
authors.forename: J
authors.initials: J
authors.lastname: Hashisho
mesh_terms: D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D005591:Chemical Fractionation; D005427:Flocculation; D007700:Kinetics; D010758:Phosphorus / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus