title: A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process for decentralized wastewater treatment.
abstract: Nitrogen discharges from decentralized wastewater treatment (DWT) systems contribute to surface and groundwater contamination. However, the high variability in loading rates, long idle periods and lack of regular maintenance presents a challenge for biological nitrogen removal in DWT. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process was developed that combines nitrate (NO3(-)) adsorption to scrap tire chips with sulfur-oxidizing denitrification. This allows the tire chips to adsorb NO3(-) when the influent loading exceeds the denitrification capacity of the biofilm and release it when NO3(-) loading rates are low (e.g. at night). Three waste products, scrap tire chips, elemental sulfur pellets and crushed oyster shells, were used as a medium in adsorption, leaching, microcosm and up-flow packed bed bioreactor studies of NO3(-) removal from synthetic nitrified DWT wastewater. Adsorption isotherms showed that scrap tire chips have an adsorption capacity of 0.66 g NO3(-)-N kg(-1) of scrap tires. Leaching and microcosm studies showed that scrap tires leach bioavailable organic carbon that can support mixotrophic metabolism, resulting in lower effluent SO4(2-) concentrations than sulfur oxidizing denitrification alone. In column studies, the T-SHAD process achieved high NO3(-)-N removal efficiencies under steady state (90%), variable flow (89%) and variable concentration (94%) conditions.
authors.affiliation: Department of Water Technology & Environmental Engineering, Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic; Department of Civil & Environmental Engineering, University of South Florida, 4202 E. Fowler Ave, ENB 118, Tampa, FL 33620, USA.
authors.forename: Lucie
authors.initials: L
authors.lastname: Krayzelova
authors.affiliation: Department of Civil & Environmental Engineering, University of South Florida, 4202 E. Fowler Ave, ENB 118, Tampa, FL 33620, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Lynn
authors.affiliation: Department of Civil & Environmental Engineering, University of South Florida, 4202 E. Fowler Ave, ENB 118, Tampa, FL 33620, USA; Department of Civil Engineering, University of Jordan, Amman 11942, Jordan.
authors.forename: Qais
authors.initials: Q
authors.lastname: Banihani
authors.affiliation: Department of Water Technology & Environmental Engineering, Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Bartacek
authors.affiliation: Department of Water Technology & Environmental Engineering, Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Jenicek
authors.affiliation: Department of Civil & Environmental Engineering, University of South Florida, 4202 E. Fowler Ave, ENB 118, Tampa, FL 33620, USA. Electronic address: sergas@usf.edu.
authors.forename: Sarina J
authors.initials: SJ
authors.lastname: Ergas
mesh_terms: D000327:Adsorption; D019149:Bioreactors; D058440:Denitrification; D009566:Nitrates / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D062611:Solid Waste; D013455:Sulfur / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000191:economics / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D009566:Nitrates; D009584:Nitrogen; D062611:Solid Waste; D013455:Sulfur; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Decentralized wastewater systems; Denitrification; Nitrate adsorption; Scrap tire chips; Sulfur oxidation